0001346302-21-000026 | 10-K | XBRL Viewer | Xeris Pharmaceuticals INC

DEI Document - USD ($) $ in Millions	12 Months Ended
DEI Document - USD ($) $ in Millions	Dec. 31, 2020	Feb. 28, 2021	Jun. 30, 2020
Document and Entity Information [Abstract]
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Voluntary Filers	No
Entity Ex Transition Period	false
Document Period End Date	Dec. 31, 2020
Entity File Number	001-38536
Entity Address, Address Line One	180 N. LaSalle Street
Entity Address, Address Line Two	Suite 1600
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
City Area Code	844
Local Phone Number	445-5704
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Trading Symbol	XERS
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		59,764,999
Entity Listing, Par Value Per Share	$ 0.0001
Entity Public Float			$ 118.4
Document Annual Report	true
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-3352427
Entity Address, Postal Zip Code	60601
Security Exchange Name	NASDAQ
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Document Type	10-K
Entity Central Index Key	0001346302
Entity Registrant Name	XERIS PHARMACEUTICALS, INC.
Entity Shell Company	false

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 37,598	$ 19,519
Short-term Investments	96,190	56,030
Trade accounts receivable, net	6,875	4,693
Inventory	8,353	2,176
Prepaid expenses and other current assets	3,196	5,065
Total current assets	152,212	87,483
Investments	0	13,231
Property and equipment, net	6,707	7,853
Other assets	232	420
Total assets	159,151	108,987
Current Liabilities
Accounts payable	3,117	5,603
Other accrued liabilities	15,895	18,119
Accrued trade discounts and rebates	5,984	1,375
Accrued returns reserve	2,889	1,957
Other current liabilities	322	284
Total current liabilities	28,207	27,338
Long-term debt, net of unamortized debt issuance costs	87,021	58,305
Long-term deferred rent	6,629	7,076
Other liabilities	3,533	1,832
Total liabilities	125,390	94,551
Commitments and contingencies (Note 9)
Stockholders' Equity
Preferred stock, par value $0.0001	0	0
Common stock, par value $0.0001	6	3
Additional paid in capital	371,134	260,635
Accumulated deficit	(337,385)	(246,245)
Accumulated other comprehensive income (loss)	6	43
Total stockholders' equity	33,761	14,436
Total liabilities and stockholders' equity	$ 159,151	$ 108,987

Consolidated Balance Sheets Parenthetical - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position Parenthetical [Abstract]
Preferred Stock, Par Value Per Share	$ 0.0001	$ 0.0001
Common Shares, Par Value Per Share	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Common Stock, Shares Authorized	150,000,000	150,000,000
Preferred Stock, Shares Issued	0	0
Common Shares, Shares, Issued	59,611,202	27,214,523

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net sales	$ 20,155	$ 1,627
Grant and other income	280	1,095
Cost of goods sold	9,328	1,603
Gross Profit	11,107	1,119
Operating expenses
Research and development	20,921	60,438
Selling, general and administrative	73,732	63,061
Total operating expenses	94,653	123,499
Loss from operations	(83,546)	(122,380)
Other income (expense)
Interest and other income	2,965	2,813
Interest expense	(10,660)	(7,163)
Change in fair value of warrants	(9)	692
Other income (expense)	(7,704)	(3,658)
Net loss before benefit from income taxes	(91,250)	(126,038)
Benefit from income taxes	110	458
Net loss	(91,140)	(125,580)
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on investments	(10)	93
Foreign currency translation adjustments	(27)	2
Comprehensive loss	$ (91,177)	$ (125,485)
Net loss per common share - basic and diluted	$ (2.14)	$ (4.81)
Weighted average common shares outstanding - basic and diluted	42,642,901	26,110,297

Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital [Member]
Common Stock, Shares, Outstanding		20,808,366
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value $0.0001		$ 2
Additional paid in capital			$ 196,121
Accumulated other comprehensive income (loss)	$ (52)
Accumulated deficit	(120,665)
Stockholders' Equity Attributable to Parent	75,406
Net loss	(125,580)
Issuance of common stock upon equity offerings, shares		6,201,202
Issuance of common stock upon equity offerings, value	57,227	$ 1	57,226
Exercise and vesting of stock options, shares		128,307
Exercise and vesting of stock options, value	254		254
Exercise of warrants, shares		3,041
Exercise of warrants, value	18		18
Stock-based compensation	6,484		6,484
Issuance of common stock through employee stock purchase plan, shares		73,607
Issuance of common stock through employee stock purchase plan, value	532		532
Accumulated Other Comprehensive Income (Loss)	95
Common Stock, Shares, Outstanding		27,214,523
Common stock, par value $0.0001	3	$ 3
Additional paid in capital	260,635		260,635
Accumulated other comprehensive income (loss)	43
Accumulated deficit	(246,245)
Stockholders' Equity Attributable to Parent	14,436
Net loss	(91,140)
Issuance of common stock upon equity offerings, shares		18,809,769
Issuance of common stock upon equity offerings, value	61,514	$ 2	61,512
Issuance of common stock upon conversion of convertible notes, shares		13,171,791
Issuance of common stock upon conversion of convertible notes, value	$ 39,937	$ 1	39,936
Exercise and vesting of stock options, shares	(100,866)	100,866
Exercise and vesting of stock options, value	$ 172		172
Stock Issued During Period, Shares, Vesting Of Restricted Stock Units		21,449
Payments Related To Tax Withholding For Share Based Compensation, RSUs	(63)		(63)
Stock-based compensation	8,273		8,273
Issuance of common stock through employee stock purchase plan, shares		292,804
Issuance of common stock through employee stock purchase plan, value	669		669
Accumulated Other Comprehensive Income (Loss)	(37)
Common Stock, Shares, Outstanding		59,611,202
Common stock, par value $0.0001	6	$ 6
Additional paid in capital	371,134		$ 371,134
Accumulated other comprehensive income (loss)	6
Accumulated deficit	(337,385)
Stockholders' Equity Attributable to Parent	$ 33,761

Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statement of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (91,140)	$ (125,580)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	1,467	1,078
Amortization of investments	84	(686)
Amortization of debt issuance costs	980	948
Stock-based compensation	8,273	6,484
Loss on conversion of convertible debt	2,124	0
Loss on extinguishment of debt	443	2,324
Change in fair value of warrants	9	(692)
Changes in operating assets and liabilities
Trade accounts receivable	(2,182)	(4,693)
Prepaid expenses and other current assets	925	(960)
Inventory	(5,143)	(2,176)
Accounts payable	(2,486)	4,737
Other accrued liabilities	(2,207)	8,912
Accrued trade discounts and rebates	4,609	1,375
Accrued returns reserve	932	1,957
Deferred rent	(447)	1,012
Other	3,201	1,614
Net cash used in operating activities	(80,558)	(104,346)
Cash flows from investing activities
Capital expenditures	(377)	(1,107)
Purchases of investments	(101,773)	(102,472)
Sales and maturities of investments	74,745	101,196
Net cash used in investing activities	(27,405)	(2,383)
Cash flows from financing activities
Proceeds from equity offerings	65,891	61,692
Payments of equity offering costs	(4,315)	(4,465)
Proceeds from issuance of debt	94,839	60,000
Repayment of debt	(25,089)	(35,000)
Payments of debt issuance costs	(5,603)	(2,381)
Payments of debt conversion costs	(400)	0
Proceeds from issuance of employee stock purchase plan shares	669	532
Proceeds from exercise of stock awards	135	152
Repurchase of common stock withheld for taxes	(63)	0
Net cash provided by financing activities	126,064	80,530
Effect of exchange rate on cash and cash equivalents	(22)	2
Increase (decrease) in cash and cash equivalents	18,079	(26,197)
Cash and cash equivalents, beginning of period	19,519	45,716
Cash and cash equivalents, end of period	37,598	19,519
Supplemental schedule of cash flow information
Cash paid for interest	4,555	3,717
Supplemental schedule of non-cash investing and financing activities
Tenant improvement allowance	0	5,658
Issuance of stock for conversion of debt	37,812	0
Accrued debt issuance costs	$ 347	$ 1,800

Organization and Nature of the Business	12 Months Ended
Organization and Nature of the Business	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of the Business	Organization and Nature of the Business Nature of business Xeris Pharmaceuticals, Inc. ("Xeris" or the "Company") is a specialty pharmaceutical company that was incorporated in Delaware in 2005. Xeris is dedicated to the development of ready-to-use injectable and infusible drug formulations that address important unmet medical needs, are easier to use by patients, caregivers and health practitioners, and reduce costs for payors and the healthcare system. Since its inception, the Company has devoted substantially all of its resources to research and development initiatives, undertaking preclinical studies of its product candidates, conducting clinical trials of its most advanced product candidates, organizing and staffing the Company, raising capital and commercializing its first product, Gvoke®, which was approved by the FDA in September 2019. Gvoke delivers ready-to-use glucagon via a commercially available pre-filled syringe or auto-injector for the treatment of severe hypoglycemia, a potentially life-threatening condition. The Company commercially launched Gvoke pre-filled syringe ("Gvoke PFS") in November 2019 and auto-injector ("Gvoke HypoPen®") in July 2020. The Company has financed its operations primarily through the issuance of its common stock, convertible debt, convertible preferred stock, and debt financing. The Company has incurred operating losses since inception and has an accumulated deficit of $337.4 million as of December 31, 2020. The Company expects to continue to incur net losses for at least the next 12 months. Based on the Company’s current operating plans and existing working capital at December 31, 2020, the Company believes its cash resources are sufficient to sustain operations and capital expenditure requirements for at least the next 12 months. The Company is subject to a number of risks similar to other specialty pharmaceutical companies, including, but not limited to, successful commercialization and market acceptance of its products and any future products, if and when approved, successful development of its product candidates, the development of new technological innovations by its competitors, and protection of intellectual property. The ongoing global outbreak of the novel coronavirus disease (“COVID-19”) has resulted in significant governmental measures being implemented to control the spread of the virus and has caused the Company to modify its business practices (including remote work for most of its employees). While we cannot predict their scope and severity, these developments and measures could materially and adversely affect our business, our results of operations and our financial condition. We are closely monitoring the impact of the COVID-19 pandemic on all aspects of our business and are taking steps to minimize its impact on our business. However, the extent to which COVID-19 impacts our business, results of operations or financial condition will depend on the extent and severity of the continued spread of COVID-19 globally, the effectiveness of actions taken to contain the pandemic or treat its impact, and the resulting economic consequences, among others. Furthermore, if we or any of the third parties with whom we engage were to experience shutdowns or other business disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially or negatively affected, which could have a material adverse impact on our business, results of operations and financial condition. Basis of presentation The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). In the opinion of management, the accompanying consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, considered necessary for a fair presentation of the Company’s financial position and its results of operations and cash flows for the periods presented. The results of operations for such periods are not necessarily indicative of the results that may be expected for any future period. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) issued by the Financial Accounting Standards Board (“FASB”). Basis of Consolidation These consolidated financial statements include the financial statements of Xeris Pharmaceuticals, Inc. and its subsidiary, Xeris Pharmaceuticals Australia Pty Ltd. All intercompany transactions have been eliminated.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

The accompanying financial statements have been prepared in conformity with GAAP. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the ASC and ASUs of the FASB.

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses included in the financial statements and accompanying notes. Actual results could differ from those estimates.

Revenue recognition

The Company applies the guidance in ASC 606 to all contracts with customers within the scope of the standard. The Company sells its product, Gvoke, which is available in two presentations, a pre-filled syringe (Gvoke PFS) and an auto-injector (Gvoke HypoPen), primarily to pharmaceutical wholesalers. These wholesalers then resell the Company’s products to their customers, such as retail pharmacies. In addition, the Company enters into arrangements with payors, group purchasing organizations, and healthcare providers that provide for government-mandated or privately-negotiated rebates, chargebacks and discounts related to the Company’s products. The Company currently sells Gvoke in the U.S. only.

Revenue is recognized when the Company's customer (e.g., a wholesaler) obtains control of promised goods or services, which is when our obligations under the terms of the contract with the customer are satisfied, based on the consideration the Company expects to receive in exchange for those goods or services. The estimated net sales price is generally based upon a list or fixed price less estimates of variable consideration (e.g., patient copay assistance, prompt payment and other discounts, payor rebates, chargebacks, service fees and product returns). The estimates of variable consideration are subject to a constraint such that some or all of the estimated amount of variable consideration will only be included in the transaction price to the extent that it is probable that a significant reversal of revenue will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Estimating variable consideration and the related constraint requires the use of significant management judgment and other market data.

Net sales represent gross product sales less estimated allowances for patient copay assistance programs, prompt payment and other discounts, payor rebates, chargebacks, service fees, and product returns, all of which are recorded at the time of sale to the pharmaceutical wholesaler or other customer. The Company applies significant judgments and estimates in determining some of these allowances. If actual results differ from its estimates, the Company will be required to make adjustments to these allowances in the future.

Patient Copay Assistance Program

The Company offers a savings program to commercially insured patients under which the cost of a prescription to a patient is discounted. The Company reimburses pharmacies for this discount through a third-party vendor. The Company records an accrual to reduce gross sales for the estimated copay on units sold to wholesalers and other customers. The estimate is based on estimated percentages of products that will be prescribed to qualified patients, expected patient utilization of the discount program, average assistance paid based on reporting from the third-party vendor as well as industry data and estimated levels of inventory in the distribution channel. Accrued copay fees are recorded as a reduction of revenue and included in accrued trade discounts and rebates on the consolidated balance sheets.

Prompt Payment Discounts

As an incentive for prompt payment, the Company offers a discount to most customers. The Company expects that all eligible customers will comply with the contractual terms to earn the discount, and, therefore, we accrue the discount on all eligible sales. The Company records the discount as an allowance against trade accounts receivable on the consolidated balance sheets and as a reduction of revenue.

Commercial Rebates

The Company contracts with certain private payor organizations, primarily insurance companies and pharmacy benefit managers, to provide rebates with respect to utilization of Gvoke and contracted formulary status. The Company accrues estimated rebates based on contract rates, estimated percentages of products that will be prescribed to qualified patients and estimated levels of inventory in the distribution channel and records the rebate as a reduction of revenue. Accrued commercial rebates are included in accrued trade discounts and rebates on the consolidated balance sheets.

Government Rebates

The Company participates in certain federal and state government rebate programs such as the Medicaid Drug Rebate Program, TRICARE Retail Refunds Program, and Medicare Part D Program. The Company accrues estimated rebates and discounts based on estimated percentages of product sold to qualified patients, estimated rebate percentages and estimated levels of inventory in the distribution channel that will be prescribed to qualified patients and records the rebates as a reduction of revenue. Accrued government rebates are included in accrued trade discounts and rebates on the consolidated balance sheets.

Chargebacks

The Company's arrangements with certain commercial and government entities allow them to buy their products directly from wholesalers at specific prices. These entities purchase products through wholesalers at the discounted price, and the wholesalers charge the difference between their acquisition cost and the discounted price back to the Company. The Company accrues estimated chargebacks based on estimated percentages of products sold to these entities, contract prices, and estimated levels of inventory in the distribution channel and records the chargebacks as a reduction of revenue. Accrued chargebacks are recorded as an allowance against trade receivables on the consolidated balance sheets.

Service Fees

The Company records service fees paid to its wholesaler customers for distribution and inventory management services as a reduction to revenue. The Company accrues estimated service fees based on contractually determined amounts. Accrued service fees are included in accrued trade discounts and rebates on the consolidated balance sheets.

Product Returns

Consistent with industry practice, the Company's customers generally have the right to return product during the period beginning six months prior to its expiration date and up to one year after its expiration date. As the Company's products are newly launched and the Company does not have a history of product returns, the Company estimates the provision for returns based on factors related to the launch of its products, third-party industry data for comparable products in the market and estimated channel inventory data. As the Company distributes its products and establishes historical sales over a longer period of time, it will be able to place more reliance on historical purchasing and return patterns of its customers when evaluating its reserves for product returns. In a reporting period, the Company may decide to constrain revenue for product returns based on information from various sources, including channel inventory levels, inventory dating, prescription data, the expiration dates of product currently being shipped, price changes of competitive products and introductions of generic products. While the Company believes that its returns reserve is sufficient to avoid a significant reversal of revenue in future periods, if it were to increase or decrease the rate by 1%, it would have a $0.2 million impact on revenue in the year ended December 31, 2020. The Company records estimated sales returns in accrued returns reserve on the consolidated balance sheets and as a reduction of revenue.

Bad debt expense

The Company’s products are primarily sold to wholesalers. The Company monitors its accounts receivable balances to determine the impact, if any, of such factors as changes in customer concentration, credit risk and the realizability of its accounts receivable, and records a bad debt reserve when applicable.

Concentration of credit risk

For the years ended December 31, 2020 and 2019, three customers accounted for 92% and 94% of the Company’s gross sales, respectively. These same three customers accounted for 98% and 97% of the trade accounts receivable at December 31, 2020 and December 31, 2019, respectively.

Cost of Goods Sold

Cost of goods sold includes primarily product costs, which include all costs directly related to the purchase of raw materials, charges from our contract manufacturing organizations, and manufacturing overhead costs, as well as shipping and distribution charges. Cost of goods sold also includes losses on excess, slow-moving or obsolete inventory and inventory purchase commitments, if any. Manufacturing costs for Gvoke incurred prior to approval and initial commercialization were expensed as research and development expenses.

Segment reporting

Operating segments are identified as components of an enterprise for which separate discrete financial information is available and utilized by the chief operating decision maker in making decisions regarding resource allocation and assessing performance. The Company operates in one segment and, other than having conducted certain clinical trials and applied for and received marketing approval for Ogluo outside the United States, all of the Company’s operations are in the United States.

Cash and cash equivalents

The Company considers all demand deposits with financial institutions and highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents.

Inventories

Inventories are stated at the lower of cost or net realizable value, using the first-in, first-out convention. Inventories consist of raw materials, work in process and finished goods. The Company has entered into manufacturing and supply agreements for the manufacture or purchase of raw materials and production supplies. The Company’s inventories include the direct purchase cost of materials and supplies, charges from our contract manufacturing organizations and manufacturing overhead costs. The Company reviews its inventory balance quarterly to assess if it has obsolete or excess inventory and records a charge to cost of goods sold if and when applicable. Manufacturing costs for Gvoke prior to approval and commercialization were expensed as research and development expenses.

Prepaid expenses and other current assets

Prepaid expenses and other current assets include prepaid expenses for general business purposes, which are stated at cost and amortized on a straight-line basis over the related period of benefit. Prepaid expenses also include supplies and materials used in several development projects. These supplies and materials are expensed as they are consumed.

Investments

The Company classifies its investments in debt securities as available-for-sale investments. Investments classified as short-term on the balance sheets have original maturities of greater than 90 days but less than one year.

Investments in available-for-sale securities are reported at estimated fair value. Available-for-sale securities consist primarily of corporate securities, U.S. government securities and commercial paper. Unrealized gains and losses related to changes in the fair value of debt securities are recognized in other comprehensive income (loss). Changes in the fair value of available-for-sale securities impact the statements of operations and comprehensive loss only when such securities are sold or an other-than-temporary impairment is recognized. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. The Company regularly reviews its investment portfolio to determine if any security is other-than-temporarily impaired, which would require an impairment charge to be recorded in the period any such determination is made. The Company considers factors such as the

duration, severity of and reason for the decline in value, the financial condition of the issuer and any changes thereto, the potential recovery period and intent to sell.

Fair value of financial instruments

Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a non-recurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, and accounts payable, are shown at cost, which approximates fair value due to the short-term nature of these instruments. The debt outstanding under the Amended and Restated Loan and Security Agreement (the "Amended Loan Agreement") approximates fair value due to the variable interest rate on the debt. Items measured at fair value on a recurring basis include the Company’s investments and warrants.

Property and equipment

Property and equipment are carried at cost less accumulated depreciation. Depreciation is calculated utilizing the straight-line method over the estimated useful lives of the respective assets:


			Lab equipment						5 years
			Computer equipment						3 years
			Leasehold improvements						Lesser of useful life or lease term
			Software						3-5 years
			Furniture and fixtures						5 years
			Office equipment						5 years

Impairment of long-lived assets

The Company periodically evaluates its long-lived assets for potential impairment in accordance with ASC Topic 360, Property, Plant and Equipment. Potential impairment is assessed when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recovered. Recoverability of these assets is assessed based on undiscounted expected future cash flows from the assets, considering a number of factors, including past operating results, budgets and economic projections, market trends and product development cycles. If impairments are identified, assets are written down to their estimated fair value. The Company recognized no material impairment charges for the years ended December 31, 2020 and 2019, respectively.

Equity financing costs

The Company capitalizes costs directly associated with equity financings until such financings are consummated, at which time such costs are recorded in additional paid in capital against the gross proceeds of the equity financings. The Company recognized $4.3 million and $4.5 million of direct costs associated with the public equity offerings in additional paid in capital for the years ended December 31, 2020 and 2019, respectively. Costs associated with the shelf registration statement on Form S-3, filed with the U.S. Securities and Exchange Commission's ("SEC") on August 6, 2019 and declared effective on August 21, 2019 have been capitalized and are being reclassified to additional paid in capital on a pro rata basis when the Company completes offerings under the shelf registration. At the end of the three-year life of the shelf registration, the remaining deferred offering costs, if any, will be charged to the results of operations. As of December 31, 2020 and 2019, $0.2 million and $0.4 million, respectively, of such deferred costs are included in other assets on the consolidated balance sheets.

Deferred rent

Certain of the Company’s lease agreements provide for scheduled rent increases during the lease term and also for abatement of some or all rental payments for a period of time after the occupancy date. In addition, certain of the Company’s lease agreements provided for tenant improvement allowances whereby the landlord funded the cost to build out the space. The Company recorded a liability for

such lease incentives which is being amortized to rent expense such that rent expense is recognized on a straight-line basis throughout the lease term.

Debt issuance costs

Debt issuance costs incurred in connection with financing arrangements are amortized to interest expense over the life of the respective financing arrangement using the effective interest method. Debt issuance costs, net of related amortization, are deducted from the carrying value of the related debt.

Warrants

The Company’s warrants are classified as liabilities as they represent a financial instrument for a share of common stock. The warrants are revalued each reporting period with the change in fair value recorded in the accompanying statements of operations until the warrants are exercised, expire, or otherwise settled.

Research and development expenses

Research and development expenses are expensed as incurred. Research and development expenses include salaries, stock compensation and other personnel-related costs, consulting fees, fees paid for contract research and development services including those for preclinical and clinical trials, laboratory equipment and facilities costs, and other external costs. In addition, manufacturing costs of products prior to approval and initial commercialization are expensed as research and development costs.

Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are received, the services are performed or the arrangement is terminated.

Stock-based compensation expense

The Company accounts for our stock-based compensation awards in accordance with ASC Topic 718, Compensation-Stock Compensation ("ASC 718"). ASC 718 requires all stock-based payments, including stock options, restricted stock units and employee stock purchases, to be recognized in the statements of operations based on their grant date fair values. The Company estimates the grant date fair value of each option award using the Black-Scholes option-pricing model. The use of the Black-Scholes option-pricing model requires management to make assumptions with respect to the expected term of the option, the expected volatility of the common stock consistent with the expected life of the option, the risk-free interest rate and the expected dividend yield of the common stock. Restricted stock units are valued based on the fair market value of the Company’s common stock on the date they were granted. The Company recognizes stock-based compensation expense equal to the grant date fair value of stock options, restricted stock units and employee stock purchases on a straight-line basis over the requisite service period. The Company accounts for forfeitures as they are incurred.

Income taxes

Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. The Company determines its deferred tax assets and liabilities based on differences between financial reporting and tax bases of assets and liabilities, which are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company's policy is to include interest and penalties related to uncertain tax positions, if any, within the provision for taxes in the statements of operations and comprehensive loss. For the years ended December 31, 2020 and 2019, the Company did not accrue any interest or penalties on uncertain tax positions.

Foreign currency translation

Our functional currency is the United States Dollar. Monetary assets and liabilities of our non-US subsidiary are remeasured using the exchange rate in effect at the end of the period. Costs in local currency are remeasured using the average exchange rate for the period. The resulting remeasurement gains and losses are included in other comprehensive income (loss).

Comprehensive loss

Comprehensive loss is defined as the change in equity during a period from transactions and other events, excluding changes resulting from investments from owners and distributions to owners. Comprehensive loss includes net loss, unrealized (gains) losses on available-for-sale investments and foreign currency translation adjustments.

Reclassifications

Certain prior period amounts on the balance sheet have been reclassified to conform to the current year presentation. These reclassifications had no impact on current assets, total assets, current liabilities or total liabilities.

New accounting pronouncements

Recently issued accounting pronouncements

In August 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity. This standard eliminates certain accounting models to simplify the accounting for convertible instruments, expands the disclosure requirements related to the terms and features of convertible instruments, and amends the guidance for the derivatives scope exception for contracts settled in an entity’s own equity. This standard enhances the consistency of earnings-per-share ("EPS") calculations by requiring that an entity use the if-converted method and that the effect of potential share settlement be included in diluted EPS calculations and disclosures. This standard will be effective for the Company for annual and interim periods beginning after December 15, 2023. Early adoption is permitted but not earlier than periods beginning after December 15, 2020. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements and disclosures.

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. This standard provides optional expedients for application of GAAP, if certain criteria are met, to contracts and other transactions that reference LIBOR or other reference rates that are expected to be discontinued because of reference rate reform. The amendments in this update are effective through December 31, 2022. The Company does not currently expect the adoption of this new standard to have a material impact on its financial statements.

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. This standard eliminates certain exceptions in the current guidance related to the approach for intraperiod tax allocation and the methodology for calculating income taxes in an interim period and amends other aspects of the guidance to help clarify and simplify U.S. GAAP. This standard will be effective for the Company for annual periods beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022, with early adoption permitted. The Company does not currently expect the adoption of this new standard to have a material impact on its financial statements.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as further updated by ASU 2018-19, 2019-04, 2019-05, 2019-10 and 2020-03. This standard requires entities to estimate an expected lifetime credit loss on financial assets ranging from short-term trade accounts receivable to long-term financings and report credit losses using an expected losses model rather than the incurred losses model that was previously used and establishes additional disclosures related to credit risks. For available-for-sale debt securities with unrealized losses, the standard will require allowances to be recorded instead of reducing the amortized cost of the investment. This standard limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and requires the reversal of previously recognized credit losses if fair value increases. This standard will be effective for the Company for annual and interim periods beginning after December 15, 2022, with early adoption permitted. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The new standard requires lessees to record a right-of-use asset and a lease liability for all leases with a term of greater than twelve months regardless of their classification. Leases will be classified as either operating or finance leases under the new guidance. Operating leases will result in straight-line expense in the income statement, similar to current operating leases, and finance leases will result in more expense being recognized in the earlier years of the lease term, similar to current capital leases. The FASB has recently extended the effective date of this standard for certain companies. This standard will be effective for the Company for fiscal years beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022. The Company is currently evaluating the impact the adoption of this new standard will have on the financial statements and related disclosures; however, since the Company is a lessee to certain leases for property whose terms exceed twelve months, it expects, once adopted, to report assets and liabilities related to these leases on its balance sheet.

Inventory (Notes)

12 Months Ended

Dec. 31, 2020

Inventory [Line Items]

Inventory Disclosure [Text Block]

Inventory

The components of inventories consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Raw materials	$	2,874	$	1,321
Work in process	4,247		662
Finished goods	1,232		193
Inventory	$	8,353	$	2,176

Inventory reserves were $2.2 million and $0 at December 31, 2020 and December 31, 2019, respectively.

Property and Equipment (Notes)

12 Months Ended

Dec. 31, 2020

Property and Equipment [Abstract]

Property, Plant and Equipment

Property and Equipment

Property and equipment consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Lab equipment	$	2,684	$	2,528
Furniture and fixtures	1,355		1,611
Computer equipment	277		232
Office equipment	8		80
Software	307		347
Leasehold improvements	4,627		4,543
	9,258		9,341
Less: accumulated depreciation and amortization	(2,551)		(1,488)
Property and equipment, net	$	6,707	$	7,853

Depreciation and amortization expense relating to property and equipment was $1.5 million and $1.1 million for the years ended December 31, 2020 and 2019, respectively.

Other Accrued Liabilities (Notes)

12 Months Ended

Dec. 31, 2020

Accrued Expenses [Abstract]

Other Accrued Liabilities

Other accrued liabilities consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Accrued employee costs	$	7,989	$	6,818
Accrued supply chain costs	1,702		—
Accrued marketing and selling costs	1,114		1,973
Accrued research and development costs	678		7,062
Accrued restructuring charges	811		—
Accrued interest expense	1,527		449
Accrued other costs	2,074		1,817
Other accrued liabilities	$	15,895	$	18,119

Long-Term Debt

12 Months Ended

Dec. 31, 2020

Long-term Debt, Unclassified [Abstract]

Long-term Debt

Convertible Senior Notes

In June 2020, the Company completed a public offering of $86.3 million aggregate principal amount of the Company's 5.00% Convertible Senior Notes due 2025 (the "Convertible Notes"), including $11.3 million pursuant to the underwriters' option to purchase additional notes which was exercised in full in July 2020. The Company incurred debt issuance costs of $5.1 million in connection with the issuance of the Convertible Notes. The Company used $20.0 million and $4.2 million of the net proceeds from the sale to prepay a portion of the principal amount on the Term A Loan (as defined below) and the remaining amount of borrowings outstanding under the PPP Loan (as defined below), respectively.

The Convertible Notes are governed by the terms of a base indenture for senior debt securities, as supplemented by the first supplemental indenture thereto, each dated as of June 30, 2020, by and between the Company and U.S. Bank National Association, as trustee. The Convertible Notes bear cash interest at the rate of 5.00% per annum, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2021, to holders of record at the close of business on the preceding January 1 and July 1, respectively. The Convertible Notes will mature on July 15, 2025, unless earlier converted or redeemed or repurchased by the Company.

At any time before the close of business on the second scheduled trading day immediately before the maturity date, holders of Convertible Notes may convert their Convertible Notes at their option into shares of the Company’s common stock, together, if applicable, with cash in lieu of any fractional share, at the then-applicable conversion rate. The conversion rate for the Convertible Notes will initially be 326.7974 shares of the Company’s common stock per $1,000 principal amount of Convertible Notes, which represents an initial conversion price of approximately $3.06 per share of common stock, and is subject to adjustment under the terms of the Convertible Notes. In the event of certain circumstances, the Company will increase the conversion rate, provided that the conversion rate will not exceed 367.6470 shares of the Company's common stock per $1,000 principal amount of Convertible Notes.

In the second half of 2020, $8.4 million in principal amount of Convertible Notes were converted into 2,736,591 shares of the Company’s common stock at the conversion rate of 326.7974 shares per $1,000 principal amount of Convertible Notes. Additionally, in the fourth quarter of 2020, the Company entered into separate, privately negotiated exchange agreements with certain holders of Convertible Notes to exchange $30.7 million in principal amount of Convertible Notes for 10,435,200 shares of the Company’s common stock. The Company recognized a $2.6 million loss related to the convertible note exchange transactions.

The Convertible Notes are senior, unsecured obligations and are equal in right of payment with the Company's existing and future senior, unsecured indebtedness, senior in right of payment to its future indebtedness, if any, that is expressly subordinated to the Convertible Notes, and effectively subordinated to its existing and future secured indebtedness to the extent of the value of the collateral securing that indebtedness. The Convertible Notes are structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent the Company is not a holder thereof) preferred equity, if any, of its subsidiaries.

Senior Secured Loan Facility

In February 2018, the Company entered into the Loan and Security Agreement, dated as of February 28, 2018 (as amended, the “Original Loan Agreement”), with Oxford Finance LLC, as the collateral agent and a lender (“Oxford”), and Silicon Valley Bank, as a lender (“SVB”, and together with Oxford, the “Lenders”), which provided for a senior secured loan facility of up to an aggregate principal amount of $45.0 million. The first tranche of $20.0 million was drawn down in February 2018 (the "2018 Term A Loan"). The second tranche of $15.0 million was drawn down in September 2018 (the "2018 Term B Loan"). The Company also issued warrants to the Lenders to purchase common stock, which is further discussed in Note 8, "Warrants."

In September 2019, the Company entered into an Amended and Restated Loan and Security Agreement (the "Loan Agreement") with the Lenders which amended and restated the Original Loan Agreement, in its entirety. The Loan Agreement provided for the Lenders to extend up to $85.0 million in term loans to the Company in three tranches. The initial tranche of $60.0 million (the “Term A Loan”) was drawn down in September 2019. Additional tranches of $15.0 million (the “Term B Loan”) and $10.0 million (the “Term C Loan”) will become available to the Company if certain revenue targets are achieved prior to March 31, 2021 and June 30, 2021, respectively. The Company currently does not anticipate that such revenue targets will be achieved. In conjunction with the execution of the Loan Agreement, the 2018 Term A Loan and 2018 Term B Loan were repaid and the final payment fee of $2.3 million was paid.

Effective April 21, 2020, the Company entered into that certain First Amendment to the Amended and Restated Loan and Security Agreement with the Lenders (the “First Amendment”) to amend the Loan Agreement to allow the Company to incur indebtedness under the U.S. Small Business Administration (the “SBA”) Paycheck Protection Program (the “PPP”) enabled by the Coronavirus Aid, Relief and Economic Security Act of 2020 (the “CARES Act”) in the amount of $5.1 million (the “PPP Loan”).

On June 30, 2020, the Company entered into that certain Second Amendment to the Amended and Restated Loan and Security Agreement with the Lenders (the "Second Amendment") to amend the Loan Agreement to provide for the Lenders’ consent to and allow for the Company's underwritten public offering of the Company's 5.00% Convertible Senior Notes due 2025 and permit the Company to prepay its PPP Loan in full. The Second Amendment also provided for the extension of the interest-only payment period through December 31, 2021, after which the term loans will be payable in 30 equal monthly installments. However, if the Company achieves a certain revenue milestone prior to January 1, 2022, then the period for interest-only payments is extended through September 30, 2022, after which the term loans will be payable in 21 equal monthly installments. In addition the Second Amendment further provided for an extension of the maturity date from June 1, 2023 to June 1, 2024. After repayment, no loans may be re-borrowed.

Pursuant to the Second Amendment, the Company prepaid a portion of the Term A Loan equal to the sum of (i) $20.0 million, plus all accrued and unpaid interest as of the date of the Second Amendment, (ii) the applicable final payment fee of $0.6 million, (iii) the applicable prepayment fee of $0.3 million and (iv) all outstanding Lenders’ expenses as of the date of the Second Amendment. Additionally, the Company is required to maintain a minimum balance of $5.0 million in unrestricted cash at SVB at all times and to pay an amendment fee of up to $0.1 million at the earliest to occur of the maturity date, acceleration of any term loan, or prepayment of any term loan amount.

On August 5, 2020, the Company entered into that certain Third Amendment to the Amended and Restated Loan and Security Agreement with the Lenders (the “Third Amendment”) to amend the Loan Agreement to (i) amend the definition of “Permitted Indebtedness” to include a new standby letter of credit in an amount not to exceed $0.4 million issued to the landlord for the Company’s new leased laboratory space and (ii) permit the sale of certain equipment related to the relocation of the Company’s research and development laboratory from San Diego to Chicago.

On October 23, 2020, the Company entered into that certain Fourth Amendment to the Amended and Restated Loan and Security Agreement with the Lenders (the "Fourth Amendment") to amend the Loan Agreement (as amended, supplemented or otherwise modified from time to time, including by that certain First Amendment, Second Amendment, Third Amendment and Fourth Amendment, collectively, the "Amended Loan Agreement") to provide an additional tranche of $3.5 million (the “Term D Loan”, and, together with the Term A Loan, Term B Loan, and Term C Loan, the "Term Loan"), available upon execution. The Term D Loan of $3.5 million was drawn in November 2020 and will be payable under the same payment terms as the Term Loans. After repayment, the loan may not be re-borrowed.

Pursuant to the Amended Loan Agreement, the Company has provided a first priority security interest in substantially all of the Company’s assets, including intellectual property, subject to certain limited exceptions.

All of the loans incur interest at a floating per annum rate in an amount equal to the sum of 6.25% plus the greater of (a) 2.43% and (b) the thirty-day U.S. Dollar LIBOR rate. For the period from the funding date of the Term A Loan through and including December 31, 2020, the interest rate was 8.68%. The remaining balance of unamortized debt issuance costs related to the Loan Agreement and the additional debt issuance costs incurred in conjunction with the Second Amendment have been reflected as a direct reduction to the loan balance and are being amortized to interest expense over the remaining life of the loan using the effective interest method.

The Amended Loan Agreement allows the Company to voluntarily prepay the outstanding amounts thereunder, but not less than $2.0 million of the outstanding principal at any time. The Company is subject to a prepayment fee equal to 1.50% of the principal amount being prepaid. Also, a final payment fee of 3.0% multiplied by the amount to be repaid is due upon the earliest to occur of the maturity date of the Amended Loan Agreement, the acceleration of the amounts outstanding under the Amended Loan Agreement or prepayment of such borrowings and is recorded in other liabilities on the consolidated balance sheets.

The Amended Loan Agreement contains customary representations and warranties, events of default (including an event of default upon a material adverse change of the Company) and affirmative and negative covenants, including, among others, covenants that limit or restrict the Company’s ability to incur additional indebtedness, grant liens, merge or consolidate, make acquisitions, pay dividends or other distributions or repurchase equity, make investments, dispose of assets and enter into certain transactions with affiliates, in each case subject to certain exceptions.

Paycheck Protection Program Loan

In April 2020, the Company entered into the SBA PPP Note with SVB (the “PPP Lender”) for the PPP Loan in the amount of $5.1 million, enabled by the CARES Act to retain employees, maintain payroll and make lease and utility payments in accordance with the relevant terms and conditions of the CARES Act. The Company repaid $0.9 million of the PPP Loan in May 2020 and the remaining $4.2 million on June 30, 2020.

The components of debt are as follows (in thousands):


	December 31, 2020		December 31, 2019

Senior secured loan facility	$	43,500	$	60,000
Convertible Notes	47,175		—
Less: unamortized debt issuance costs	(3,654)		(1,695)
Long-term debt, net of unamortized debt issuance costs	$	87,021	$	58,305

The following table sets forth the Company’s future minimum principal payments on the senior secured loan facility and the Convertible Notes (in thousands):


2021	$	0
2022	17,400
2023	17,400
2024	8,700
2025	47,175
	$	90,675

For the year ended December 31, 2020, the Company recognized interest expense of $10.7 million, of which $1.0 million related to the amortization of debt issuance costs. Included in such interest expense are a loss on conversion of convertible debt and a loss on extinguishment of debt of $2.6 million and $0.7 million, respectively. For the year ended December 31, 2019, the Company recognized interest expense of $7.2 million, of which $0.9 million related to the amortization of debt issuance costs. Included in such interest expense is a loss on extinguishment of debt of $2.3 million relating to the write-off of the remaining balance of unamortized debt issuance costs associated with the Original Loan Agreement.

Public Stock Offerings	12 Months Ended
Public Stock Offerings	Dec. 31, 2020
Reverse Stock Split and Initial Public Offering [Abstract]
Reverse Stock Split and Initial Public Offering	Stockholders' Equity The Company’s authorized shares of stock of 160.0 million are divided into 150.0 million shares of common stock, par value $0.0001 per share, and 10.0 million shares of preferred stock, par value $0.0001 per share. At December 31, 2020 none of the 10.0 million shares of preferred stock were outstanding, and the Company has no present plans to issue any shares of preferred stock. The Company’s board of directors has the authority, without action by the Company’s stockholders, to designate and issue the preferred stock in one or more series and to designate the rights, preferences, limitations and privileges of each series of preferred stock, which may be greater than the rights of the Company’s common stock. The Company has not paid any cash dividends on its common stock during the periods presented. In February 2019, the Company completed an equity offering of its common stock pursuant to a registration statement on Form S-1, as amended. The Company sold an aggregate of 5,996,775 shares of common stock at a price of $10.00 per share, including 116,775 shares of common stock pursuant to the exercise of the underwriters' option to purchase additional shares. Net proceeds from the equity offering were $55.5 million after deducting underwriting discounts and commissions as well as other public offering expenses. On August 6, 2019, the Company filed a shelf registration statement on Form S-3 with the SEC, which covers the offering, issuance and sale by the Company of up to an aggregate of $250.0 million of its common stock, preferred stock, debt securities, warrants and/or units (the "Shelf"). The Company simultaneously entered into a Sales Agreement with Jefferies LLC, as sales agent, to provide for the offering, issuance and sale by the Company of up to $50.0 million of its common stock from time to time in "at-the-market" offerings under the Shelf. The Shelf was declared effective by the SEC on August 21, 2019. In December 2019, the Company sold an aggregate of 204,427 shares of common stock under the Shelf for net proceeds of $1.7 million after deducting selling commissions as well as other public offering expenses. In February 2020, the Company completed an equity offering of its common stock pursuant to the Shelf. The Company sold an aggregate of 10,299,769 shares of common stock at a price of $4.15 per share, including 1,299,769 shares pursuant to the underwriters’ option to purchase additional shares of common stock. Net proceeds from the equity offering were approximately $39.9 million after deducting underwriting discounts and commissions as well as other public offering expenses. In June 2020, the Company completed an equity offering of its common stock pursuant to the Shelf. The Company sold an aggregate of 8,510,000 shares of common stock at a price of $2.72 per share, including 1,110,000 shares pursuant to the underwriters' option to purchase additional shares which was fully exercised in July 2020. Net proceeds from the equity offering were approximately $21.6 million after deducting underwriting discounts and commissions as well as other public offering expenses. In the second half of 2020, $8.4 million in principal amount of Convertible Notes were converted into 2,736,591 shares of the Company’s common stock at the conversion rate of 326.7974 shares per $1,000 principal amount of Convertible Notes. Additionally, in the fourth quarter of 2020, the Company entered into separate, privately negotiated exchange agreements with certain holders of Convertible Notes to exchange $30.7 million in principal amount of Convertible Notes for 10,435,200 shares of the Company’s common stock. Upon vesting and settlement of RSUs or exercise of stock options, at the election of the grantee, the Company does not collect withholding taxes in cash from employees. Instead, the Company withholds upon settlement as RSUs vest, or as stock options are exercised, the portion of those shares with a fair market value equal to the amount of the minimum statutory withholding taxes due. The withheld shares are accounted for as repurchases of common stock. The Company then pays the minimum statutory withholding taxes in cash. During the year ended December 31, 2020, 31,250 RSUs vested for which 9,801 shares were withheld to cover the minimum statutory withholding taxes of $0.1 million.

Warrants (Notes)

12 Months Ended

Dec. 31, 2020

Warrants [Abstract]

Other Liabilities Disclosure

Warrants

In 2014 the Company issued 19,931 warrants (the “2014 Warrants”) to certain investors. The 2014 Warrants allow each holder to purchase one share of common stock for $5.912. Of the 2014 Warrants, 18,512 warrants were exercised and 1,419 warrants expired. There are no 2014 Warrants outstanding as of December 31, 2020.

As part of the Original Loan Agreement discussed in Note 6, "Long-term Debt," the Lenders received warrants concurrent with the borrowing. The warrants represent a right for the lender to purchase shares of the Company’s common stock at an exercise price of

$11.169 per share. The Company issued 53,720 warrants (the "2018 Term A Warrants") upon the drawdown of the 2018 Term A Loan in February 2018, and the Company issued 40,292 warrants (the "2018 Term B Warrants") upon the drawdown of the 2018 Term B Loan in September 2018. There have been no exercises of 2018 Term A Warrants or 2018 Term B Warrants.

Because the warrants are a freestanding instrument, indexed to the Company's stock, they do not meet the criteria for equity classification. Therefore, the warrants are classified as liabilities and subject to remeasurement at each reporting period until they are exercised, expired, or otherwise settled.

The Company recognized gains (losses) of $4,000, ($8,000) and ($5,000) upon the change in fair value of the warrants during the year ended December 31, 2020 related to the 2014 Warrants, the 2018 Term A Warrants and the 2018 Term B Warrants, respectively. The Company recognized gains of $78,000, $351,000 and $263,000 upon the change in fair value of the warrants during the year ended December 31, 2019 related to the 2014 Warrants, the 2018 Term A Warrants and the 2018 Term B Warrants, respectively.

As of December 31, 2020, the following warrants were outstanding:


	Outstanding Warrants	Exercise Price per Warrant	Expiration Date

2018 Term A Warrants	53,720	$11.169	February 2025
2018 Term B Warrants	40,292	$11.169	September 2025
	94,012

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments

The Company has non-cancellable operating leases for office and laboratory space, which expire at various times through 2033. The non-cancellable lease agreements provide for monthly lease payments which increase during the term of each lease agreement.

In the third quarter of 2020, the Company signed a lease to occupy a research and development laboratory site in Chicago, Illinois in conjunction with the Company's plan to relocate such activities from the current San Diego site in the fourth quarter of 2020. The future minimum lease payments of the new lease are approximately $0 in 2021, $0.5 million in 2022, $0.7 million in 2023, $0.7 million in 2024, $0.7 million in 2025, and $6.5 million in 2026 and thereafter. In conjunction with the new lease, the Company assigned its lease for the San Diego site to a third party in the fourth quarter of 2020. Such assignment released the Company from any further minimum lease payment obligations for that site.

Future minimum lease payments under operating leases at December 31, 2020 are as follows (in thousands):


2021	$	1,277
2022	1,813
2023	2,031
2024	1,981
2025	1,931
Thereafter	13,723
Total minimum lease payments	$	22,756

Total rent expense under these operating leases was approximately $2.3 million and $2.2 million for the years ended December 31, 2020 and 2019, respectively.

As of December 31, 2020, we had unused letters of credit of $1.4 million which were issued primarily to secure leases.

LitigationFrom time to time, the Company may become involved in various legal actions arising in the ordinary course of business. As of December 31, 2020, management was not aware of any existing, pending or threatened legal actions that would have a material impact on the financial position or results of operations of the Company.

Restructuring and Related Activities

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Restructuring and Related Activities Disclosure

Restructuring Costs

In the third quarter of 2020, the Company commenced a plan to relocate its research and development laboratory from San Diego to Chicago. The costs associated with the plan include employee termination and relocation costs and other facility exit costs. The Company expects to incur total restructuring costs of approximately $2.3 million related to the plan. Costs of $1.7 million were incurred in the year ended December 31, 2020, of which $1.0 million is included in research and development expenses, $0.6 million is included in selling, general and administrative expenses, and $0.1 million is included in costs of goods sold in the consolidated statements of operations and comprehensive loss. The Company anticipates that the restructuring will be substantially complete by the end of the fourth quarter of 2021. The restructuring reserve is included in other accrued liabilities in the consolidated balance sheet.

The following table summarizes the initial restructuring reserve and the payments made during the year ended December 31, 2020 (in thousands):


	Employee Termination and Relocation Costs		Other		Total
Restructuring costs	$	1,215	$	445	$	1,660
Payments	(569)		(280)		(849)
Balance accrued at December 31, 2020	$	646	$	165	$	811

Stock Compensation Plan (Notes)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock Compensation Plan

In 2011, the Company adopted the 2011 Stock Option Issuance Plan (the “2011 Plan”) and subsequently amended it to authorize the Board of Directors to issue up to 4,714,982 incentive stock option and non-qualified stock option awards.

The 2018 Stock Option and Incentive Plan (the "2018 Plan") was adopted by the Board of Directors in April 2018 and approved by the Company's stockholders in June 2018 to award up to 1,822,000 shares of common stock. This plan became effective on the date immediately prior to the effectiveness of the Company's IPO registration statement. The 2018 Plan replaced the 2011 Plan as the Board of Directors decided not to make additional awards under the 2011 Plan following the closing of the IPO, which occurred in June 2018. The 2018 Plan allows the compensation committee to make equity-based and cash-based incentive awards to the Company's officers, employees, directors and other key persons (including consultants). No grants of stock options or other awards may be made under the 2018 Plan after the tenth anniversary of the effective date.

The 2018 Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2019, and each January 1 thereafter, by 4% of the outstanding number of shares of our common stock on the immediately preceding December 31, or such lesser number of shares as determined by the compensation committee. This number is subject to adjustment in the event of a stock split, stock dividend or other change affecting the Company's common stock. On January 1, 2020 and 2019, the number of shares of common stock available for issuance under the 2018 Plan was automatically increased by 1,088,580 shares and 835,728 shares, respectively. As of December 31, 2020, there were 609,757 shares of common stock available for future issuance under the 2018 plan.

The 2018 Employee Stock Purchase Plan (the "ESPP") was adopted by the Board of Directors in April 2018 and approved by the Company's stockholders in June 2018 to issue up to 193,000 shares of common stock to participating employees. Through the ESPP, eligible employees may authorize payroll deductions of up to 15% of their compensation to purchase up to the number of shares of common stock determined by dividing $25,000 by the closing market price of Xeris common stock on the offering date. The purchase price per share at each purchase date is equal to 85% of the lower of (i) the closing market price per share of Xeris common stock on the employee’s offering date or (ii) the closing market price per share of Xeris common stock on the purchase date. Each offering period has a six-month duration and purchase interval with a purchase date of the last business day of June and December each year.

This plan became effective on the date immediately prior to the effectiveness of the Company's IPO registration statement. The ESPP provides that the number of shares reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2019 and each January 1 thereafter through January 1, 2028, by the least of (i) 1% of the outstanding number of shares of our common stock on the immediately preceding December 31; (ii) 386,000 shares or (iii) such lesser number of shares as determined by the ESPP administrator. On January 1, 2020 and 2019, the number of shares of common stock available for issuance under the ESPP increased by 272,145 shares and 208,932 shares, respectively. The number of shares reserved under the ESPP is subject to adjustment in the event of a stock split, stock dividend or other change affecting the Company's common stock. The Company issued 292,804 shares at a weighted average price of $2.29 per share during the year ended December 31, 2020. As of December 31, 2020, there were 307,666 shares available for issuance under the ESPP.

The Equity Inducement Plan (the "Inducement Plan") was adopted by the Board of Directors in February 2019. The Inducement Plan was adopted without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. The Inducement Plan allows the Company to make stock option or restricted stock unit awards to prospective employees of the Company as an inducement to such individuals to commence employment with the Company. The Company intends to use this Inducement Plan to help it attract and retain prospective employees who are necessary to support the commercial launch of Gvoke and the expansion of the Company generally. The Company initially reserved 750,000 shares of common stock for the issuance of awards under the Inducement Plan. This number is subject to adjustment in the event of a stock split, stock dividend or other change affecting the Company's common stock. As of December 31, 2020, there were 263,794 shares of common stock available for future issuance under the Inducement Plan.

On October 8, 2020, the Company's stockholders, upon recommendation of the Board of Directors, approved an amendment to the Company's 2011 Plan and 2018 Plan to allow the Company to permit certain employee option holders, subject to specified conditions, to exchange some or all of their outstanding options to purchase shares of the Company's common stock for a lesser number of new options to purchase shares of the Company’s common stock (the “Option Exchange”).

On November 10, 2020, the Company filed with the SEC a Tender Offer Statement on Schedule TO defining the terms and conditions of the Option Exchange. The total number of shares of common stock underlying a new option with respect to an exchanged eligible option was determined by dividing the number of shares of common stock underlying the exchanged eligible option by the applicable exchange ratio and rounding to the nearest whole number, subject to the terms and conditions described in the Exchange Offer. On December 10, 2020, the completion date of the Option Exchange, the Company canceled the options accepted for exchange and granted 832,907 new options to purchase shares of common stock in exchange for 1,127,906 options issued under the 2011 Plan and 2018 Plan. The exercise price per share of the options granted pursuant to the Exchange Offer was $4.09 per share, which was the closing price per share of common stock on The Nasdaq Global Select Market on the grant date of such new options. The new options will vest and become exercisable in two equal installments following the grant date, subject to an option holder's continuous service, and expire seven years from the grant date. On the grant date, the fair values of the options exchanged were similar to the fair values of the new options granted and, as such, the incremental compensation cost related to the Option Exchange was not material.

Stock options are granted with an exercise price equal to the market price of the Company’s stock at the date of grant. Stock option awards typically vest over either two, three or four years after the grant date and expire seven to ten years from the grant date.

The fair value of each option is estimated on the date of grant using a Black-Scholes option valuation model that uses the assumptions noted in the following table. The expected term of options represents the period of time that options granted are expected to be outstanding. The risk-free interest rate for periods during the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected stock price volatility assumption is based on the historical volatilities of a peer group of publicly traded companies as well as the historical volatility of the Company's common stock since the Company began trading subsequent to its IPO in June 2018 over the period corresponding to the expected life as of the grant date. The expected dividend yield is based on the expected annual dividend as a percentage of the market value of the Company’s ordinary shares as of the grant date.

The fair value of stock options granted, excluding those issued pursuant to the Option Exchange, was estimated with the following weighted average assumptions:


	Years Ended December 31,
	2020		2019
Expected term (years)	5.9		6.0
Risk-free interest rate	0.42	%	2.14	%
Expected volatility	70.19	%	60.27	%
Expected dividends	—		—

Stock option activity under the 2011 Plan, 2018 Plan and Inducement Plan for the year ended December 31, 2020 was as follows:


	Options	Weighted Average Exercise Price		Weighted Average Contractual Life (Years)
Outstanding - January 1, 2020	4,428,985	$	9.40	8.19
Granted	1,555,668	5.15
Issued upon Option Exchange	832,907	4.09
Cancelled upon Option Exchange	(1,127,906)	16.05
Exercised and vested	(100,866)	1.68
Forfeited	(534,691)	9.07
Expired	(100,191)	10.15
Outstanding - December 31, 2020	4,953,906	$	5.84	7.46
Exercisable - December 31, 2020	2,173,599	$	5.77	6.38
Vested and expected to vest at December 31, 2020	4,704,371	$	5.84	7.42

The weighted average fair value of awards granted during the year ended December 31, 2020 was $3.13 per share. The total intrinsic value of options exercised during the year ended December 31, 2020 was $0.2 million. As of December 31, 2020, the aggregate intrinsic value of awards vested and expected to vest was $5.4 million.

At December 31, 2020, there was a total of $11.4 million of unrecognized stock-based compensation expense related to stock options that is expected to be recognized over a weighted average period of 2.1 years.

A summary of outstanding RSU awards and the activity for the year ended December 31, 2020 was as follows:


	Units	Weighted Average Grant Date Fair Value
Unvested balance - January 1, 2020	125,000	$	13.88
Granted	677,800	6.12
Vested	(31,250)	13.88
Forfeited	(5,000)	6.37
Unvested balance - December 31, 2020	766,550	$	7.07

RSUs are measured based on the fair market value of the underlying stock on the date of grant and vest over either three or four years in equal annual installments beginning on the one-year anniversary of the date of grant. Stock-based compensation expense related to RSUs is recognized on a straight-line basis over the employee’s requisite service period. As of December 31, 2020, there was $3.9 million of unrecognized stock-based compensation expense related to RSUs, which is expected to be recognized over the weighted-average remaining vesting period of 2.3 years.

The fair value of the ESPP Plan shares was estimated using the Black-Scholes option-pricing model with the following weighted average assumptions:


	Years Ended December 31,
	2020		2019
Expected term (years)	0.5		0.5
Risk-free interest rate	1.01	%	1.85	%
Expected volatility	108.70	%	70.70	%
Expected dividends	—		—

The following table summarizes the reporting of total stock-based compensation expense resulting from stock options, RSUs and the ESPP (in thousands):


	Years Ended December 31,
	2020		2019

Cost of goods sold	$	151	$	—
Research and development	1,229		1,168
Selling, general and administrative	6,893		5,316
Total stock-based compensation expense	$	8,273	$	6,484

Fair Value Measurement

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurement

Fair Value Measurements

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are classified and disclosed in one of the following categories:

Level 1: Measured using unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

Level 2: Measured using quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and

Level 3: Measured based on prices or valuation models that require inputs that are both significant to the fair value measurement and less observable from objective sources (i.e., supported by little or no market activity).

Fair value measurements are classified based on the lowest level of input that is significant to the measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of the assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values stated below takes into account the market for its financial assets and liabilities, the associated credit risk and other factors as required. The Company considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

The following tables present the Company’s fair value hierarchy for those assets and liabilities measured at fair value as of December 31, 2020 and 2019 (in thousands):


	Total as of December 31, 2020		Level 1		Level 2		Level 3

Assets
Cash and cash equivalents:
Cash and money market funds	$	37,598	$	37,598	$	—	$	—

Investments:
U.S. government securities	64,386		64,386		—		—
Corporate securities	13,625		—		13,625		—

Commercial paper	18,179		—		18,179		—
Total investments	$	96,190	$	64,386	$	31,804	$	—

Liabilities
Warrant liabilities	$	159	$	—	$	—	$	159


	Total as of December 31, 2019		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents:
Cash and money market funds	$	19,519	$	19,519	$	—	$	—

Investments:
U.S. government securities	32,175		32,175		—		—
Corporate securities	22,164		—		22,164		—
Commercial paper	14,922		—		14,922		—
Total investments	$	69,261	$	32,175	$	37,086	$	—

Liabilities
Warrant liabilities	$	150	$	—	$	—	$	150

The fair value of the Company’s warrant liabilities is based on a Black-Scholes valuation which considers the expected term of the warrants as well as the risk-free interest rate and expected volatility of the Company's common stock.

The Company has determined that the warrant liabilities' fair values are Level 3 items within the fair value hierarchy. The following table presents the change in the warrant liabilities (in thousands):



Balance at December 31, 2019	$	150
Change in fair value of warrants	9
Balance at December 31, 2020	$	159

There were no transfers between any of the levels of the fair value hierarchy during the years ended December 31, 2020 and 2019.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Available-for-Sale Investments (Notes)

12 Months Ended

Dec. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Short-term investments

Available-for-Sale Investments

The Company classifies its investments in debt securities as available-for-sale. Debt securities are comprised of highly liquid investments with minimum “A” rated securities and, as of December 31, 2020, consist of U.S. Treasury and agency bonds and corporate entity commercial paper and securities, all with maturities of more than three months but less than one year at the date of purchase. Debt securities as of December 31, 2020 had an average remaining maturity of 0.4 years. The debt securities are reported at fair value with unrealized gains or losses recorded in other comprehensive income (loss). Refer to Note 12, "Fair Value Measurements," for information related to the fair value measurements and valuation methods utilized.

The following table represents the Company’s available-for-sale investments by major security type as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value

Investments:
Commercial paper	$	18,179	$	—	$	—	$	18,179
Corporate securities	13,597		29		(1)		13,625
U.S. government securities	64,383		7		(4)		64,386
Total available-for-sale investments	$	96,159	$	36	$	(5)	$	96,190

	December 31, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value

Investments:
Commercial paper	$	14,922	$	—	$	—	$	14,922
Corporate securities	22,146		20		(2)		22,164
U.S. government securities	32,152		23		—		32,175
Total available-for-sale investments	$	69,220	$	43	$	(2)	$	69,261

The Company reviews available-for-sale investments for other-than-temporary impairment loss periodically. The Company considers factors such as the duration, severity of and reason for the decline in value, the potential recovery period and our intent to sell. For debt securities, we also consider whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis and (ii) the amortized cost basis cannot be recovered as a result of credit losses. During the years ended December 31, 2020 and 2019, the Company did not recognize any other-than-temporary impairment losses. All marketable securities with unrealized losses have been in a loss position for less than twelve months.

Net Loss Per Share (Notes)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings Per Share [Text Block]

Net Loss Per Common ShareBasic and diluted net loss per common share are determined by dividing net loss applicable to common stockholders by the weighted average common shares outstanding during the period. For all periods presented, the shares issuable upon conversion, exercise or vesting of Convertible Notes, warrants, stock option awards and RSUs have been excluded from the calculation because their effects would be anti-dilutive. Therefore, the weighted average common shares outstanding used to calculate both basic and diluted net loss per common share are the same.

The following potentially dilutive securities were excluded from the computation of diluted weighted average common shares outstanding due to their anti-dilutive effect:


	As of December 31,
	2020	2019
Shares to be issued upon conversion of Convertible Notes	15,416,667	—
Vested and unvested stock options	4,953,906	4,428,985
Restricted stock units	766,550	125,000
Warrants	94,012	95,431
	21,231,135	4,649,416

Other Employee Benefit Plans (Notes)	12 Months Ended
Other Employee Benefit Plans (Notes)	Dec. 31, 2020
Postemployment Benefits [Abstract]
Compensation and Employee Benefit Plans	Other Employee Benefit Plans Defined Contribution Plan The Company sponsors an employee retirement plan qualifying under Section 401(k) of the Internal Revenue Code for all eligible employees in the United States. Employees become eligible to contribute to the plan upon meeting certain age requirements and 30 days of service. Commencing in 2019, the Company began discretionary matching employee contributions up to certain limits. For the years ended December 31, 2020 and 2019, the Company made $0.6 million and $0.4 million of matching contributions to the plan, respectively. Defined Compensation Plan The Compensation Committee of the Board of Directors adopted a deferred compensation plan ("Deferred Compensation Plan") in April 2020. The Deferred Compensation Plan allows a select group of executive management and non-employee directors to defer payment of certain of their cash compensation. Participants in the Deferred Compensation Plan who are employees may defer all or a portion of their annual base salaries and all or a portion of their annual cash performance-based compensation. Participants who are non-employee directors may defer all or a portion of their annual cash retainers. The participants’ elective deferrals are 100% vested immediately and accrue interest at a rate of two percent per annum. The Deferred Compensation Plan is unfunded and unsecured. As of December 31, 2020, the total deferred compensation liability under the Deferred Compensation Plan was approximately $1.7 million and was recorded in other liabilities in the consolidated balance sheets.

Income Taxes (Notes)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Tax Disclosure

Income Taxes

A reconciliation of the expected income tax benefit computed using the federal statutory income tax rate of 21% to the Company’s effective income tax rate is as follows (in thousands):



	Years Ended December 31,
	2020		2019
Federal tax benefit at statutory rate	$	(19,162)	$	(26,468)
State tax benefit, net of federal benefit	(4,375)		(5,570)

Research and development and orphan drug credits	(480)		(2,912)
Uncertain tax positions	(16)		342
Permanent adjustments to expenses	710		169
Stock-based compensation	1,014		683
Return to provision adjustment	(1,203)		(3,278)

Changes in valuation allowance	23,543		36,288
Other	(141)		288
Total income tax benefit	$	(110)	$	(458)

The benefit for income taxes for 2020 is attributable to an Australian research and development tax incentive that was refunded to the Company based on the 2020 income tax filing.

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of the assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. A valuation allowance is required to be established or maintained when, based on currently available information, it is more likely than not that all or a portion of a deferred tax asset will not be realized. The guidance on accounting for income taxes provides important factors in determining whether a deferred tax asset will be realized, including whether there has been sufficient taxable income in recent years and whether sufficient income can reasonably be expected in future years in order to utilize the deferred tax asset. For the year ended December 31, 2020, we have evaluated the need to maintain a valuation allowance for deferred tax assets based on our assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance.

Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2020		2019
Deferred tax assets:
Net operating losses	$	74,894	$	55,110
Federal research and orphan drug credits	8,362		8,309
Stock-based compensation	1,894		1,092
Other temporary differences	7,785		4,648
Valuation allowance	(92,493)		(68,950)
Total assets	442		209
Deferred tax liabilities:
Fixed and intangible assets	(404)		(155)
Other deferred tax liabilities	(38)		(54)
Total liabilities	(442)		(209)
Net deferred tax assets	$	—	$	—

As of December 31, 2020, the Company had federal net operating loss carryforwards of $284.8 million and various state net operating loss carryforwards of $220.6 million. As of December 31, 2019, the Company had federal net operating loss carryforwards of $215.3 million and various state net operating loss carryforwards of $147.5 million. Net operating loss carryforwards for U.S. federal income tax purposes that were generated prior to January 1, 2018 have a twenty-year carryforward life, and the earliest layers will begin to expire in 2025. Under the Tax Cuts and Jobs Act of 2017, federal net operating losses incurred in 2018 and later years may be carried forward indefinitely, but the deductibility of such net operating losses is limited to 80% of the current year’s taxable income. U.S. state net operating loss carryforwards will start to expire in 2029 for the earliest net operating loss layers to the extent there is not sufficient state taxable income to utilize those net operating loss carryforwards.

At December 31, 2020, the Company had $8.0 million and $1.7 million of federal and state income tax credits, respectively, to reduce future tax liabilities. At December 31, 2019, the Company had $8.3 million and $1.0 million of federal and state income tax credits, respectively, to reduce future tax liabilities. The federal income tax credits consist primarily of orphan drug credits and research and development credits. The U.S. state income tax credits consist primarily of California and Illinois research and development credits. Both the U.S. federal orphan drug credits and research and development credits have a twenty-year carryforward life. The U.S. federal orphan drug credits and research and development credits will both begin to expire in 2025.

A reconciliation of the beginning and ending amounts of valuation allowances for the years ended December 31, 2020 and 2019 is as follows (in thousands):



Valuation allowance at December 31, 2018	$	(32,662)
Increase for 2019 activity	(36,288)
Valuation allowance at December 31, 2019	(68,950)
Increase for 2020 activity	(23,543)
Valuation allowance at December 31, 2020	$	(92,493)

The Company is required to recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. The Company accounts for the uncertainty in income taxes by utilizing a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken, or are expected to be taken, on an income tax return. The changes in the Company's uncertain income tax positions for the years ended December 31, 2020 and 2019, excluding interest and penalties, consisted of the following (in thousands):


	December 31,
	2020		2019
Beginning balance - uncertain tax positions	$	945	$	603
Increases related to tax positions taken during the current year	48		246
Increases (decreases) related to tax positions taken during the prior year	(64)		96
Ending balance - uncertain tax positions	$	929	$	945

For the year ended December 31, 2020, the increase in current year uncertain tax positions was attributable primarily to U.S. federal orphan drug credits and research and development credits and the decrease related to tax positions taken during the prior year was a result of return to provision adjustments. In the Company’s balance sheet, uncertain tax positions of $0.9 million were offset against deferred tax assets. Tax years prior to 2017 generally are not subject to examination by the Internal Revenue Service or state or local taxing authorities.

The Company policy is to include interest and penalties related to uncertain tax penalties, if any, within the provision for taxes in the statements of operations. During the years ended December 31, 2020 and 2019, the Company incurred no interest and penalties related to income taxes.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies [Abstract]

Revenue Recognition, Sales of Goods [Policy Text Block]

Revenue recognition

Patient Copay Assistance Program

Prompt Payment Discounts

Commercial Rebates

Government Rebates

Chargebacks

Service Fees

Product Returns

Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block]

Bad debt expense

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentration of credit risk

Cost of Goods and Service [Policy Text Block]

Cost of Goods Sold

Segment Reporting, Policy [Policy Text Block]

Segment reporting

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash and cash equivalents The Company considers all demand deposits with financial institutions and highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents.

Inventory, Policy [Policy Text Block]

InventoriesInventories are stated at the lower of cost or net realizable value, using the first-in, first-out convention. Inventories consist of raw materials, work in process and finished goods. The Company has entered into manufacturing and supply agreements for the manufacture or purchase of raw materials and production supplies. The Company’s inventories include the direct purchase cost of materials and supplies, charges from our contract manufacturing organizations and manufacturing overhead costs. The Company reviews its inventory balance quarterly to assess if it has obsolete or excess inventory and records a charge to cost of goods sold if and when applicable. Manufacturing costs for Gvoke prior to approval and commercialization were expensed as research and development expenses.

Investment, Policy [Policy Text Block]

Investments

duration, severity of and reason for the decline in value, the financial condition of the issuer and any changes thereto, the potential recovery period and intent to sell.

Fair Value Measurement, Policy [Policy Text Block]

Fair value of financial instruments

Property, Plant and Equipment, Policy

Property and equipment

Property and equipment are carried at cost less accumulated depreciation. Depreciation is calculated utilizing the straight-line method over the estimated useful lives of the respective assets:


			Lab equipment						5 years
			Computer equipment						3 years
			Leasehold improvements						Lesser of useful life or lease term
			Software						3-5 years
			Furniture and fixtures						5 years
			Office equipment						5 years

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Impairment of long-lived assetsThe Company periodically evaluates its long-lived assets for potential impairment in accordance with ASC Topic 360, Property, Plant and Equipment. Potential impairment is assessed when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recovered. Recoverability of these assets is assessed based on undiscounted expected future cash flows from the assets, considering a number of factors, including past operating results, budgets and economic projections, market trends and product development cycles. If impairments are identified, assets are written down to their estimated fair value. The Company recognized no material impairment charges for the years ended December 31, 2020 and 2019, respectively.

Research and Development Expense, Policy [Policy Text Block]

Research and development expenses

Share-based Payment Arrangement [Policy Text Block]

Stock-based compensation expense

Income Tax, Policy [Policy Text Block]

Income taxes

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign currency translation

Comprehensive Income, Policy [Policy Text Block]

Comprehensive loss

Reclassification, Policy [Policy Text Block]

Reclassifications

New Accounting Pronouncements, Policy [Policy Text Block]

New accounting pronouncements

Recently issued accounting pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Line Items]

Schedule of Property and Equipment Useful Lives [Table Text Block]

Property and equipment are carried at cost less accumulated depreciation. Depreciation is calculated utilizing the straight-line method over the estimated useful lives of the respective assets:


			Lab equipment						5 years
			Computer equipment						3 years
			Leasehold improvements						Lesser of useful life or lease term
			Software						3-5 years
			Furniture and fixtures						5 years
			Office equipment						5 years

Inventory (Tables)

12 Months Ended

Dec. 31, 2020

Inventory [Line Items]

Schedule of Inventory

The components of inventories consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Raw materials	$	2,874	$	1,321
Work in process	4,247		662
Finished goods	1,232		193
Inventory	$	8,353	$	2,176

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property and Equipment [Abstract]

Property, Plant and Equipment

Property and equipment consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Lab equipment	$	2,684	$	2,528
Furniture and fixtures	1,355		1,611
Computer equipment	277		232
Office equipment	8		80
Software	307		347
Leasehold improvements	4,627		4,543
	9,258		9,341
Less: accumulated depreciation and amortization	(2,551)		(1,488)
Property and equipment, net	$	6,707	$	7,853

Other Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Accrued Expenses [Abstract]

Other Accrued Liabilities

Other accrued liabilities consisted of the following (in thousands):


	December 31, 2020		December 31, 2019

Accrued employee costs	$	7,989	$	6,818
Accrued supply chain costs	1,702		—
Accrued marketing and selling costs	1,114		1,973
Accrued research and development costs	678		7,062
Accrued restructuring charges	811		—
Accrued interest expense	1,527		449
Accrued other costs	2,074		1,817
Other accrued liabilities	$	15,895	$	18,119

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2020

Long-term Debt, Unclassified [Abstract]

Schedule of Long-term Debt Instruments

The components of debt are as follows (in thousands):


	December 31, 2020		December 31, 2019

Senior secured loan facility	$	43,500	$	60,000
Convertible Notes	47,175		—
Less: unamortized debt issuance costs	(3,654)		(1,695)
Long-term debt, net of unamortized debt issuance costs	$	87,021	$	58,305

Schedule of Maturities of Long-term Debt

The following table sets forth the Company’s future minimum principal payments on the senior secured loan facility and the Convertible Notes (in thousands):


2021	$	0
2022	17,400
2023	17,400
2024	8,700
2025	47,175
	$	90,675

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

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+ Details

Warrants (Tables)

12 Months Ended

Dec. 31, 2020

Warrants [Abstract]

Schedule of Stockholders' Equity Note, Warrants or Rights

As of December 31, 2020, the following warrants were outstanding:


	Outstanding Warrants	Exercise Price per Warrant	Expiration Date

2018 Term A Warrants	53,720	$11.169	February 2025
2018 Term B Warrants	40,292	$11.169	September 2025
	94,012

Commitments and Contingencies Future Minimum Lease Payments (Tables)

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases

Future minimum lease payments under operating leases at December 31, 2020 are as follows (in thousands):


2021	$	1,277
2022	1,813
2023	2,031
2024	1,981
2025	1,931
Thereafter	13,723
Total minimum lease payments	$	22,756

Restructuring and Related Activities (Tables)

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Restructuring and Related Costs

The following table summarizes the initial restructuring reserve and the payments made during the year ended December 31, 2020 (in thousands):


	Employee Termination and Relocation Costs		Other		Total
Restructuring costs	$	1,215	$	445	$	1,660
Payments	(569)		(280)		(849)
Balance accrued at December 31, 2020	$	646	$	165	$	811

Stock Compensation Plan (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]


	Units	Weighted Average Grant Date Fair Value
Unvested balance - January 1, 2020	125,000	$	13.88
Granted	677,800	6.12
Vested	(31,250)	13.88
Forfeited	(5,000)	6.37
Unvested balance - December 31, 2020	766,550	$	7.07

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

The following table summarizes the reporting of total stock-based compensation expense resulting from stock options, RSUs and the ESPP (in thousands):


	Years Ended December 31,
	2020		2019

Cost of goods sold	$	151	$	—
Research and development	1,229		1,168
Selling, general and administrative	6,893		5,316
Total stock-based compensation expense	$	8,273	$	6,484

Share-based Payment Arrangement, Option [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-based Compensation Assumptions Used in Black-Scholes Option Valuation Model

The fair value of stock options granted, excluding those issued pursuant to the Option Exchange, was estimated with the following weighted average assumptions:


	Years Ended December 31,
	2020		2019
Expected term (years)	5.9		6.0
Risk-free interest rate	0.42	%	2.14	%
Expected volatility	70.19	%	60.27	%
Expected dividends	—		—

Share-based Compensation, Activity

Stock option activity under the 2011 Plan, 2018 Plan and Inducement Plan for the year ended December 31, 2020 was as follows:


	Options	Weighted Average Exercise Price		Weighted Average Contractual Life (Years)
Outstanding - January 1, 2020	4,428,985	$	9.40	8.19
Granted	1,555,668	5.15
Issued upon Option Exchange	832,907	4.09
Cancelled upon Option Exchange	(1,127,906)	16.05
Exercised and vested	(100,866)	1.68
Forfeited	(534,691)	9.07
Expired	(100,191)	10.15
Outstanding - December 31, 2020	4,953,906	$	5.84	7.46
Exercisable - December 31, 2020	2,173,599	$	5.77	6.38
Vested and expected to vest at December 31, 2020	4,704,371	$	5.84	7.42

Restricted stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair value of the ESPP Plan shares was estimated using the Black-Scholes option-pricing model with the following weighted average assumptions:


	Years Ended December 31,
	2020		2019
Expected term (years)	0.5		0.5
Risk-free interest rate	1.01	%	1.85	%
Expected volatility	108.70	%	70.70	%
Expected dividends	—		—

Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring

The following tables present the Company’s fair value hierarchy for those assets and liabilities measured at fair value as of December 31, 2020 and 2019 (in thousands):


	Total as of December 31, 2020		Level 1		Level 2		Level 3

Assets
Cash and cash equivalents:
Cash and money market funds	$	37,598	$	37,598	$	—	$	—

Investments:
U.S. government securities	64,386		64,386		—		—
Corporate securities	13,625		—		13,625		—

Commercial paper	18,179		—		18,179		—
Total investments	$	96,190	$	64,386	$	31,804	$	—

Liabilities
Warrant liabilities	$	159	$	—	$	—	$	159


	Total as of December 31, 2019		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents:
Cash and money market funds	$	19,519	$	19,519	$	—	$	—

Investments:
U.S. government securities	32,175		32,175		—		—
Corporate securities	22,164		—		22,164		—
Commercial paper	14,922		—		14,922		—
Total investments	$	69,261	$	32,175	$	37,086	$	—

Liabilities
Warrant liabilities	$	150	$	—	$	—	$	150

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation



Balance at December 31, 2019	$	150
Change in fair value of warrants	9
Balance at December 31, 2020	$	159

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Available-for-Sale Investments (Tables)

12 Months Ended

Dec. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Debt Securities, Available-for-sale

The following table represents the Company’s available-for-sale investments by major security type as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value

Investments:
Commercial paper	$	18,179	$	—	$	—	$	18,179
Corporate securities	13,597		29		(1)		13,625
U.S. government securities	64,383		7		(4)		64,386
Total available-for-sale investments	$	96,159	$	36	$	(5)	$	96,190

	December 31, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value

Investments:
Commercial paper	$	14,922	$	—	$	—	$	14,922
Corporate securities	22,146		20		(2)		22,164
U.S. government securities	32,152		23		—		32,175
Total available-for-sale investments	$	69,220	$	43	$	(2)	$	69,261

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following potentially dilutive securities were excluded from the computation of diluted weighted average common shares outstanding due to their anti-dilutive effect:


	As of December 31,
	2020	2019
Shares to be issued upon conversion of Convertible Notes	15,416,667	—
Vested and unvested stock options	4,953,906	4,428,985
Restricted stock units	766,550	125,000
Warrants	94,012	95,431
	21,231,135	4,649,416

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

The following table summarizes the reporting of total stock-based compensation expense resulting from stock options, RSUs and the ESPP (in thousands):


	Years Ended December 31,
	2020		2019

Cost of goods sold	$	151	$	—
Research and development	1,229		1,168
Selling, general and administrative	6,893		5,316
Total stock-based compensation expense	$	8,273	$	6,484

Summary of Valuation Allowance [Table Text Block]

A reconciliation of the beginning and ending amounts of valuation allowances for the years ended December 31, 2020 and 2019 is as follows (in thousands):



Valuation allowance at December 31, 2018	$	(32,662)
Increase for 2019 activity	(36,288)
Valuation allowance at December 31, 2019	(68,950)
Increase for 2020 activity	(23,543)
Valuation allowance at December 31, 2020	$	(92,493)

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the expected income tax benefit computed using the federal statutory income tax rate of 21% to the Company’s effective income tax rate is as follows (in thousands):



	Years Ended December 31,
	2020		2019
Federal tax benefit at statutory rate	$	(19,162)	$	(26,468)
State tax benefit, net of federal benefit	(4,375)		(5,570)

Research and development and orphan drug credits	(480)		(2,912)
Uncertain tax positions	(16)		342
Permanent adjustments to expenses	710		169
Stock-based compensation	1,014		683
Return to provision adjustment	(1,203)		(3,278)

Changes in valuation allowance	23,543		36,288
Other	(141)		288
Total income tax benefit	$	(110)	$	(458)

Schedule of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2020		2019
Deferred tax assets:
Net operating losses	$	74,894	$	55,110
Federal research and orphan drug credits	8,362		8,309
Stock-based compensation	1,894		1,092
Other temporary differences	7,785		4,648
Valuation allowance	(92,493)		(68,950)
Total assets	442		209
Deferred tax liabilities:
Fixed and intangible assets	(404)		(155)
Other deferred tax liabilities	(38)		(54)
Total liabilities	(442)		(209)
Net deferred tax assets	$	—	$	—

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]


	December 31,
	2020		2019
Beginning balance - uncertain tax positions	$	945	$	603
Increases related to tax positions taken during the current year	48		246
Increases (decreases) related to tax positions taken during the prior year	(64)		96
Ending balance - uncertain tax positions	$	929	$	945

Organization and Nature of the Business Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net sales	$ 20,155	$ 1,627
Accumulated deficit	$ 337,385	$ 246,245	$ 120,665

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 32
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Paragraph 32
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130545-203045

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-Name Accounting Standards Codification
-Topic 924
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-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Summary of Significant Accounting Policies Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Concentration risk, number of major customers	3
Payments of equity offering costs	$ (4,315)	$ (4,465)
Capitalized costs, public offering costs	$ 200	$ 400
A change of returns reserve percentage	1.00%
Impact on revenue if returns reserve changed by 1%	$ 200
Concentration Risk, Percentage of Gross Revenue	9200.00%	94.00%
Concentration Risk, Percentage of Accounts Receivable	98.00%	97.00%
Payments of public offering costs	$ 4,315	$ 4,465
Additional Paid-in Capital [Member]
Property, Plant and Equipment [Line Items]
Payments of equity offering costs	(4,300)	(4,500)
Payments of public offering costs	$ 4,300	$ 4,500
Lab equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Computer equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	Lesser of useful life or lease term
Software \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Software \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Office equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years

Summary of Significant Accounting Policies Summary of Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Accounting Policies [Abstract]
Concentration risk, number of major customers	3
Concentration Risk, Percentage of Gross Revenue	9200.00%	94.00%
Payments of public offering costs	$ 4,315	$ 4,465
Concentration Risk, Percentage of Accounts Receivable	98.00%	97.00%

Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventory Valuation Reserves	$ 2,200	$ 0

Inventory Components of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Raw materials	$ 2,874	$ 1,321
Work in process	4,247	662
Finished goods	1,232	193
Inventory	$ 8,353	$ 2,176

Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,258	$ 9,341
Less: accumulated depreciation and amortization	(2,551)	(1,488)
Property and equipment, net	6,707	7,853
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,684	2,528
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,355	1,611
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	277	232
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8	80
Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	307	347
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,627	$ 4,543

Property and Equipment Property and equipment details (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation Depletion and Amortization, not including asset impairments	$ 1,500	$ 1,100

Other Accrued Liabilities Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Expenses [Abstract]
Accrued employee costs	$ 7,989	$ 6,818
Accrued supply chain costs	1,702	0
Accrued marketing and selling costs	1,114	1,973
Accrued research and development costs	678	7,062
Accrued restructuring charges	811	0
Accrued interest expense	1,527	449
Accrued other costs	2,074	1,817
Other accrued liabilities	$ 15,895	$ 18,119

Long-Term Debt Debt, Future Principal Payments (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Debt Disclosure [Abstract]
Future principal payments, 2021	$ 0
Future principal payments, 2022	17,400
Future principal payments, 2023	17,400
Future principal payments, 2024	8,700
Future principal payments, 2025	47,175
Debt Instrument, Face Amount	$ 90,675

Long-Term Debt Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2020	May 31, 2020	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Oct. 23, 2020	Jul. 07, 2020	Apr. 21, 2020	Sep. 30, 2018	Mar. 31, 2018
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 90,675		$ 90,675		$ 90,675
Prepayment allowed per debt agreement			$ 2,000		$ 2,000		$ 2,000
Prepayment penalty percentage							1.50%
Final payment fee percentage			3.00%		3.00%		3.00%
Interest expense							$ 10,660	$ 7,163
Long-term Debt			$ 87,021		$ 87,021		87,021	58,305
Amortization of debt issuance costs							980	948
Unamortized Debt Issuance Expense			(3,654)		$ (3,654)		(3,654)	(1,695)
Convertible notes purchased, due to exercise of underwriter option										$ 11,300
Initial conversion rate for Convertible Notes					326.7974
Per principal amount of Convertible Notes					$ 1
Principal amount of convertible notes converted					$ 8,400
Issuance of common stock upon conversion of convertible notes, shares					2,736,591
Principal amount of convertible notes converted privately			$ 30,700
Stock Issued During Period, Shares, Conversion of Convertible Securities privately exchanged			10,435,200
Loss on the convertible note exchange transactions							2,600
Letters of Credit Outstanding, Amount			$ 1,400		$ 1,400		1,400
Loss on extinguishment of debt							443	$ 2,324
Chicago Fulton Market
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount			$ 400		$ 400		$ 400
2018 Term A Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount													$ 20,000
2018 Term B Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount												$ 15,000
2018 Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity													$ 45,000
Amended Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 85,000
Term A Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						60,000
Debt Instrument, Interest Rate, Stated Percentage			6.25%		6.25%		6.25%
Debt Instrument, Basis Spread on Variable Rate							2.43%
Interest rate, stated percentage plus greater of (a) 2.43% or (b) thirty-day LIBOR			8.68%		8.68%		8.68%
Repayments of Notes Payable				$ 20,000			$ 20,000
Final payment fee settled at closing						600
Prepayment fee settled at closing							300
Minimum cash balance to be held with lender							5,000
Amendment fee to be settled at maturity			$ 100		$ 100		$ 100
Term A Loan [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Payment Terms							30
Term A Loan [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Payment Terms							21
Term B Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						15,000
Term C Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 10,000
2018 Term A & B Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Fee								2.3 million
Senior Loans
Debt Instrument [Line Items]
Debt Instrument, Face Amount			43,500		43,500		$ 43,500	$ 60,000
Amortization of debt issuance costs								900
Loss on extinguishment of debt							700	2,300
Convertible Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 47,175		$ 47,175		$ 47,175	0		86,300
Debt Issuance Costs, Gross										$ 5,100
Cash interest per annum on convertible notes			5.00%		5.00%		5.00%			5.00%
Initial conversion rate for Convertible Notes							326.7974
Per principal amount of Convertible Notes							$ 1
Debt Instrument, Convertible, Conversion Price			$ 3.06		$ 3.06		$ 3.06
Maximum conversion rate of Convertible Notes							367.6470
PPP Loan
Debt Instrument [Line Items]
Repayments of Notes Payable	$ 4,200	$ 900		$ 4,200
Notes Payable											$ 5,100
Term D Loan
Debt Instrument [Line Items]
Debt Instrument, Face Amount									$ 3,500
Debt
Debt Instrument [Line Items]
Interest expense							$ 10,700	$ 7,200
Amortization of debt issuance costs							$ 1,000

Public Stock Offerings Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2020	Jul. 15, 2020	Feb. 14, 2020	Dec. 30, 2019	Aug. 06, 2019	Feb. 19, 2019
Reverse Stock Split and Initial Public Offering [Abstract]
Common Shares, Par Value Per Share	$ 0.0001	$ 0.0001			$ 0.0001	$ 0.0001
Common Shares, Shares, Issued	27,214,523	59,611,202			59,611,202	59,611,202	8,510,000	10,299,769	204,427		5,996,775
Shares Issued, Price Per Share							$ 2.72	$ 4.15			$ 10.00
Common shares issued, due to exercise of underwriter option		1,110,000	1,299,769		1,110,000	1,110,000					116,775
Net proceeds from issuance of public offering	$ 1,700		$ 39,900	$ 55,500		$ 21,600
Aggregate amount of common stock, available to sell under a shelf registration										$ 250,000
Aggregate amount of common stock, available to sell under at-the-market (ATM) offering										$ 50,000
Total common stock and preferred stock authorized shares		160,000,000.0			160,000,000.0	160,000,000.0
Common Stock, Shares Authorized	150,000,000	150,000,000			150,000,000	150,000,000
Preferred Stock, Shares Authorized	10,000,000	10,000,000			10,000,000	10,000,000
Preferred Stock, Par Value Per Share	$ 0.0001	$ 0.0001			$ 0.0001	$ 0.0001
Restricted stock units vested and settled during period						31,250
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation						9,801
Statutory withholding taxes on vesting and settlement of RSUs						$ 100
Principal amount of convertible notes converted					$ 8,400
Issuance of common stock upon conversion of convertible notes, shares					2,736,591
Initial conversion rate for Convertible Notes					326.7974
Per principal amount of Convertible Notes					$ 1
Principal amount of convertible notes converted privately		$ 30,700
Stock Issued During Period, Shares, Conversion of Convertible Securities privately exchanged		10,435,200

Warrants Schedule of Stockholders' Equity Note, Warrants or Rights (Details)	Dec. 31, 2020 $ / shares shares
Class of Warrant or Right [Line Items]
Outstanding warrants \| shares	94,012
2014 Warrants [Member]
Class of Warrant or Right [Line Items]
Exercise Price Per Warrant \| $ / shares	$ 5.912
Term A Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants \| shares	53,720
Exercise Price Per Warrant \| $ / shares	$ 11.169
Term B Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants \| shares	40,292
Exercise Price Per Warrant \| $ / shares	$ 11.169

Warrants Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended			23 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2014	Aug. 20, 2020
Class of Warrant or Right [Line Items]
Outstanding warrants			94,012
Change in fair value of warrants			$ 9	$ (692)
Term A Warrants [Member]
Class of Warrant or Right [Line Items]
Preferred stock and warrants issued during the period, shares		53,720
Exercise Price Per Warrant			$ 11.169
Class of warrants, exercised			0
Outstanding warrants			53,720
Change in fair value of warrants			$ (8)	351
Term B Warrants [Member]
Class of Warrant or Right [Line Items]
Preferred stock and warrants issued during the period, shares	40,292
Exercise Price Per Warrant			$ 11.169
Class of warrants, exercised			0
Outstanding warrants			40,292
Change in fair value of warrants			$ (5)	263
2014 Warrants [Member]
Class of Warrant or Right [Line Items]
Preferred stock and warrants issued during the period, shares					19,931
Exercise Price Per Warrant			$ 5.912
Class of warrants, exercised						18,512
Change in fair value of warrants			$ 4	$ 78
Class of warrants, expired			1,419

Commitments and Contingencies Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Remaining future minimum lease payments, 2021	$ 1,277
Remaining future minimum lease payments, 2022	1,813
Remaining future minimum lease payments, 2023	2,031
Remaining future minimum lease payments, 2024	1,981
Remaining future minimum lease payments, 2025	1,931
Remaining future minimum lease payments, thereafter	13,723
Total minimum lease payments	22,756
Rent Expense, operating leases	2,300	$ 2,200
Letters of Credit Outstanding, Amount	1,400
Other Commitments [Line Items]
Remaining future minimum lease payments, 2021	1,277
Remaining future minimum lease payments, 2022	1,813
Remaining future minimum lease payments, 2023	2,031
Remaining future minimum lease payments, 2024	1,981
Remaining future minimum lease payments, 2025	1,931
Remaining future minimum lease payments, thereafter	13,723
Chicago Fulton Market
Commitments and Contingencies Disclosure [Abstract]
Remaining future minimum lease payments, 2021	0
Remaining future minimum lease payments, 2022	500
Remaining future minimum lease payments, 2023	700
Remaining future minimum lease payments, 2024	700
Remaining future minimum lease payments, 2025	700
Remaining future minimum lease payments, thereafter	6,500
Letters of Credit Outstanding, Amount	400
Other Commitments [Line Items]
Remaining future minimum lease payments, 2021	0
Remaining future minimum lease payments, 2022	500
Remaining future minimum lease payments, 2023	700
Remaining future minimum lease payments, 2024	700
Remaining future minimum lease payments, 2025	700
Remaining future minimum lease payments, thereafter	$ 6,500

Restructuring and Related Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Related Cost, Expected Cost	$ 2,300
Restructuring costs	1,660
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,660
Payments	(849)
Accrued restructuring charges	811	$ 0
Research and development expense
Restructuring and Related Activities [Abstract]
Restructuring costs	1,000
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,000
Selling, General and Administrative Expenses [Member]
Restructuring and Related Activities [Abstract]
Restructuring costs	600
Restructuring Cost and Reserve [Line Items]
Restructuring costs	600
Cost of Sales
Restructuring and Related Activities [Abstract]
Restructuring costs	100
Restructuring Cost and Reserve [Line Items]
Restructuring costs	100
Employee Severance
Restructuring and Related Activities [Abstract]
Restructuring costs	1,215
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,215
Payments	(569)
Accrued restructuring charges	646
Other Restructuring
Restructuring and Related Activities [Abstract]
Restructuring costs	445
Restructuring Cost and Reserve [Line Items]
Restructuring costs	445
Payments	(280)
Accrued restructuring charges	$ 165

Stock Compensation Plan Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	5 years 10 months 24 days	6 years
Risk-free interest rate	0.42%	2.14%
Expected volatility	70.19%	60.27%
Expected dividends	0.00%	0.00%
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 months	6 months
Risk-free interest rate	1.01%	1.85%
Expected volatility	108.70%	70.70%
Expected dividends	0.00%	0.00%

Stock Compensation Plan Employee Stock Award Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	4,953,906	4,428,985
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 5.84	$ 9.40
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	7 years 5 months 15 days	8 years 2 months 8 days
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	1,555,668
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 5.15
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period upon Option Exchange, Weighted Average Exercise Price	$ 4.09
Share-based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period upon Option Exchange	832,907
Share-based Compensation Arrangements by Share-based Payment Award, Options, Cancelled upon Option Exchange in Period, Weighted Average Exercise Price	$ 16.05
Share-based Compensation Arrangement by Share-based Payment Award, Options, Cancelled upon Option exchange	(1,127,906)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(100,866)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 1.68
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares	(534,691)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 9.07
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	(100,191)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price	$ 10.15
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	2,173,599
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 5.77
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	6 years 4 months 17 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	4,704,371
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 5.84
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	7 years 5 months 1 day
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.42%	2.14%

Stock Compensation Plan Narrative (Details) - USD ($)	12 Months Ended
Stock Compensation Plan Narrative (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Least amount of annual increase of shares available for issuance	386,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period upon Option Exchange, Weighted Average Exercise Price	$ 4.09
Share-based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period upon Option Exchange	832,907
Share-based Compensation Arrangement by Share-based Payment Award, Options, Cancelled upon Option exchange	(1,127,906)
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value	$ 3.13
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value	5,400,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 11,400,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 1 month 6 days
Share-based Payment Arrangement, Option [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Share-based Payment Arrangement, Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Non--employee stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	2 years
Exchange Offer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	7 years
2011 Stock Option Issuance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized						4,714,982
2018 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			1,822,000
Percentage shares available for issuance automatically increase annually	4.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	1,088,580	835,728
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	609,757
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized					193,000
Maximum employee payroll deduction percentage	15.00%
Common stock value, tax limit on employee stock purchase plan	$ 25,000
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	85.00%
Percentage shares available for issuance automatically increase annually	1.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	272,145	208,932
Issuance of common stock through employee stock purchase plan, shares	292,804
Employee Stock Ownership Plan (ESOP), Weighted Average Purchase Price of Shares Purchased	$ 2.29
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	307,666
Equity Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized				750,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	263,794

Stock Compensation Plan Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 8,273	$ 6,484
Research and development expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1,229	1,168
Selling, General and Administrative Expenses [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	6,893	5,316
Cost of Sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 151	$ 0

Stock Compensation Plan Restricted stock units, activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	4,953,906	4,428,985
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	1,555,668
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 7.07	$ 13.88
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	6.12
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	13.88
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 6.37
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.01%	1.85%
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 3.9
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 3 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	766,550	125,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	677,800
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(31,250)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(5,000)
Expected dividends	0.00%	0.00%
Expected volatility	108.70%	70.70%
Expected term	6 months	6 months

Fair Value Measurement Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and money market funds	$ 37,598	$ 19,519
Investments	96,190	69,261
Other current liabilities	159	150
Change in fair value of warrants	(9)	692
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and money market funds	37,598	19,519
Investments	64,386	32,175
Other current liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and money market funds	0	0
Investments	31,804	37,086
Other current liabilities	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and money market funds	0	0
Investments	0	0
Other current liabilities	159	150
U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	64,386	32,175
U.S. government securities \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	64,386	32,175
U.S. government securities \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
U.S. government securities \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	13,625	22,164
Corporate securities \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Corporate securities \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	13,625	22,164
Corporate securities \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	18,179	14,922
Commercial paper \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Commercial paper \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	18,179	14,922
Commercial paper \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 0	$ 0

Available-for-Sale Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Available For Sale Securities Maturities Period	4 months 24 days
Amortized Cost	$ 96,159	$ 69,220
Gross Unrealized Gains	36	43
Gross Unrealized Losses	(5)	(2)
Investments	96,190	69,261
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	18,179	14,922
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Investments	18,179	14,922
Corporate securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,597	22,146
Gross Unrealized Gains	29	20
Gross Unrealized Losses	(1)	(2)
Investments	13,625	22,164
U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	64,383	32,152
Gross Unrealized Gains	7	23
Gross Unrealized Losses	(4)	0
Investments	$ 64,386	$ 32,175

Net Loss Per Share Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	21,231,135	4,649,416
Shares to be issued upon conversion of Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	15,416,667	0
Vested and unvested stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,953,906	4,428,985
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	766,550	125,000
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	94,012	95,431

Other Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Defined Contribution Plan, Matching Contributions	$ 600	$ 400
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 1,700
Deferred Compensation Arrangement with Individual, Cash Awards Granted, Percentage	10000.00%
Deferred compensation, accrued interest rate	200.00%

Income Taxes (Details) - USD ($)	12 Months Ended
Income Taxes (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance [Line Items]
Operating Loss Carryforwards	$ 284,800,000	$ 215,300,000
Effective Income Tax Rate Reconciliation, Deduction, Percent	80.00%
Federal research income tax credits, gross of valuation allowance	$ 8,000,000.0	8,300,000
State research income tax credits, gross of valuation allowance	1,700,000	1,000,000.0
Operating loss carryforwards, various states	220,600,000	147,500,000
Federal tax benefit at statutory rate	(19,162,000)	(26,468,000)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	(4,375,000)	(5,570,000)
Unrecognized Tax Benefits	$ 929,000	945,000	$ 603,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 48,000	246,000
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	(64,000)	96,000
Net operating losses	74,894,000	55,110,000
Deferred Tax Assets, Tax Credit Carryforwards, Research	8,362,000	8,309,000
Stock compensation	1,894,000	1,092,000
Other temporary differences	7,785,000	4,648,000
Valuation allowance	(92,493,000)	(68,950,000)	$ (32,662,000)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(23,543,000)	(36,288,000)
Total deferred tax assets	442,000	209,000
Fixed and intangible assets	(404,000)	(155,000)
Deferred Tax Liabilities, Other	(38,000)	(54,000)
Total deferred tax liabilities	(442,000)	(209,000)
Net deferred tax assets	0	0
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	23,543,000	36,288,000
Benefit from income taxes	(110,000)	(458,000)
Income Tax Examination, Penalties and Interest Expense	0
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount	(480,000)	(2,912,000)
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	(16,000)	342,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	710,000	169,000
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount	1,014,000	683,000
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(1,203,000)	(3,278,000)
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount	$ (141,000)	$ 288,000