Chimerix (CMRX) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-35867
Entity Registrant Name	CHIMERIX, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0903395
Entity Address, Address Line One	2505 Meridian Parkway
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Durham
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27713
City Area Code	919
Local Phone Number	806-1074
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	CMRX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		86,211,412
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001117480
Current Fiscal Year End Date	--12-31

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 32,080	$ 46,989
Short-term investments, available-for-sale	112,898	31,973
Accounts receivable	482	340
Prepaid expenses and other current assets	2,677	2,356
Total current assets	148,137	81,658
Long-term investments	7,548	0
Property and equipment, net of accumulated depreciation	218	214
Operating lease right-of-use assets	2,717	2,825
Other long-term assets	29	26
Total assets	158,649	84,723
Current liabilities:
Accounts payable	2,181	1,283
Accrued liabilities	6,067	7,250
Note payable	14,000	0
Total current liabilities	22,248	8,533
Lease-related obligations	2,752	2,814
Total liabilities	25,000	11,347
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized at March 31, 2021 and December 31, 2020; no shares issued and outstanding as of March 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value, 200,000,000 shares authorized at March 31, 2021 and December 31, 2020; 86,208,279 and 62,816,039 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	86	63
Additional paid-in capital	943,381	785,673
Accumulated other comprehensive loss, net	(43)	0
Accumulated deficit	(809,775)	(712,360)
Total stockholders’ equity	133,649	73,376
Total liabilities and stockholders’ equity	$ 158,649	$ 84,723

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	86,208,279	62,816,039
Common stock, shares outstanding (in shares)	86,208,279	62,816,039

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Total revenues	$ 1,435	$ 1,241
Operating expenses:
Research and development	11,862	8,949
General and administrative	4,136	3,205
Acquired in-process research and development	82,890	0
Total operating expenses	98,888	12,154
Loss from operations	(97,453)	(10,913)
Other income:
Interest income and other, net	38	493
Net loss	(97,415)	(10,420)
Other comprehensive loss:
Unrealized loss on debt investments, net	(43)	(46)
Comprehensive loss	$ (97,458)	$ (10,466)
Per share information:
Net loss, basic and diluted (in dollars per share)	$ (1.21)	$ (0.17)
Weighted-average shares outstanding, basic and diluted (in shares)	80,204,094	61,742,035
Contract and grant revenue
Total revenues	$ 1,433	$ 1,171
Licensing revenue
Total revenues	$ 2	$ 70

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		61,590,013
Beginning Balance at Dec. 31, 2019	$ 109,952	$ 62	$ 778,693	$ 35	$ (668,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		61,930,339
Share-based compensation	1,326		1,326
Employee stock purchase plan purchases	229		229
Employee stock purchase plan purchases (in shares)		177,193
RSU stock issuance (in shares)		163,133
Comprehensive loss:
Unrealized loss on investments, net	(46)			(46)
Net loss	(10,420)				(10,420)
Comprehensive loss	(10,466)
Ending Balance at Mar. 31, 2020	101,041	$ 62	780,248	(11)	(679,258)
Ending balance (in shares) at Mar. 31, 2020		61,930,339
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		61,930,339
Beginning balance (in shares)		62,816,039
Beginning Balance at Dec. 31, 2020	73,376	$ 63	785,673	0	(712,360)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		86,208,279
Share-based compensation	2,584		2,584
Exercise of stock options	3,530	$ 1	3,529
Exercise of stock options (in shares)		710,132
Employee stock purchase plan purchases	330		330
Employee stock purchase plan purchases (in shares)		259,837
RSU stock issuance (in shares)		168,752
Issuance of common stock related to asset acquisition	43,445	$ 9	43,436
Issuance of common stock related to asset acquisition (in shares)		8,723,769
Issuance of common stock, net of issuance costs of $7.2 million	107,842	$ 13	107,829
Issuance of common stock, net of issuance costs $7.2 million (in shares)		13,529,750
Comprehensive loss:
Unrealized loss on investments, net	(43)			(43)
Net loss	(97,415)				(97,415)
Comprehensive loss	(97,458)
Ending Balance at Mar. 31, 2021	$ 133,649	$ 86	$ 943,381	$ (43)	$ (809,775)
Ending balance (in shares) at Mar. 31, 2021		86,208,279
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		86,208,279

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 7.2

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (97,415)	$ (10,420)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	71	112
Amortization of discount/premium on investments	128	(191)
Share-based compensation	2,584	1,326
Fair value of common stock issued related to asset acquisition	43,445	0
Note payable related to asset acquisition	14,000	0
Gain on sale of investments	(2)	0
Lease-related amortization	41	(21)
Changes in operating assets and liabilities:
Accounts receivable	(159)	154
Prepaid expenses and other assets	(309)	762
Accounts payable and accrued liabilities	(280)	(2,542)
Net cash used in operating activities	(37,896)	(10,820)
Cash flows from investing activities:
Purchases of property and equipment	(75)	(7)
Purchases of short-term investments	(91,944)	(27,652)
Purchases of long-term investments	(7,554)	0
Proceeds from sales of short-term investments	2,007	0
Proceeds from maturities of short-term investments	8,850	45,902
Net cash (used in) provided by investing activities	(88,716)	18,243
Cash flows from financing activities:
Proceeds from exercise of stock options	3,530	0
Proceeds from employee stock purchase plan	330	229
Proceeds from issuance of common stock, net of commissions	107,843	0
Net cash provided by financing activities	111,703	229
Net (decrease) increase in cash and cash equivalents	(14,909)	7,652
Cash and cash equivalents:
Beginning of period	46,989	16,901
End of period	$ 32,080	$ 24,553

The Business and Summary of Sig

The Business and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
The Business and Summary of Significant Accounting Policies	The Business and Summary of Significant Accounting Policies Description of Business Chimerix is a development-stage biopharmaceutical company dedicated to accelerating the advancement of innovative medicines that make a meaningful impact in the lives of patients living with cancer and other serious diseases. Our three most advanced clinical-stage development programs are brincidofovir (BCV), ONC201 and dociparstat sodium (DSTAT). BCV is an antiviral drug candidate developed as a potential medical countermeasure for smallpox and is currently under review for regulatory approval in the United States. ONC201 is currently being investigated in a number of efficacy studies for recurrent H3 K27M-mutant glioma and a blinded independent central review, potentially sufficient for accelerated approval, when considered with the totality of the other safety and efficacy data, is expected later this year. DSTAT is in Phase 3 development as a potential first-line therapy in acute myeloid leukemia (AML) and as a potential treatment for acute lung injury (ALI) in COVID-19 patients. Basis of Presentation The accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s audited financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of the Company’s management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented have been included. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the full year, for any other interim period or for any future year. Fair Value of Financial Instruments The carrying amounts of certain financial instruments, including accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short-term nature of such instruments. For assets and liabilities recorded at fair value, it is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements, in accordance with the fair value hierarchy. Fair value measurements for assets and liabilities where there exists limited or no observable market data are based primarily upon estimates and are often calculated based on the economic and competitive environment, the characteristics of the asset or liability and other factors. Therefore, fair value measurements cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there may be inherent weaknesses in any calculation technique and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the calculated current or future fair values. The Company utilizes fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. The Company groups assets and liabilities at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. The determination of where an asset or liability falls in the hierarchy requires significant judgment. These levels are: • Level 1 — Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2 — Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and models for which all significant inputs are observable, either directly or indirectly. • Level 3 — Valuations based on inputs that are unobservable and significant to the overall fair value measurement. At March 31, 2021 and December 31, 2020, the Company had cash equivalents including money market funds, whose value is based on quoted market prices. At March 31, 2021 and December 31, 2020, the Company had short-term investments, including U.S. Treasury securities, whose value is based on quoted market prices. At March 31, 2021, the Company had long-term investments including U.S. Treasury securities, whose value is based on quoted market prices. Accordingly, these securities are classified as Level 1. At March 31, 2021, the Company had short-term investments, including commercial paper and corporate bonds and on December 31, 2020, the Company had short-term investments including corporate bonds. At March 31, 2021, the Company had long-term investments including U.S. Treasury securities. As quoted prices are not available for these securities, they are valued using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security’s credit rating, prepayment assumptions and other factors such as credit loss assumptions. Accordingly, these securities are classified as Level 2. There was no material re-measurement to fair value of financial assets and liabilities that are not measured at fair value on a recurring basis. For additional information regarding the Company's investments, please refer to Note 2, "Investments." Below are tables that present information about certain assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements March 31, 2021 Total Quoted Prices in Significant Other Significant Cash equivalents Money market funds $ 26,990 $ 26,990 $ — $ — Total cash equivalents 26,990 26,990 — — Short-term investments U.S. treasury securities 21,064 21,064 — — Commercial paper 57,524 — 57,524 — Corporate bonds 34,310 — 34,310 — Total short-term investments 112,898 21,064 91,834 — Long-term investments U.S. treasury securities 7,548 2,553 4,995 — Total long-term investments 7,548 2,553 4,995 — Total assets $ 147,436 $ 50,607 $ 96,829 $ — Fair Value Measurements December 31, 2020 Total Quoted Prices in Significant Other Significant Cash equivalents Money market funds $ 1,503 $ 1,503 $ — $ — Total cash equivalents 1,503 1,503 — — Short-term investments U.S. treasury securities 28,715 28,715 — — Corporate bonds 3,258 — 3,258 — Total short-term investments 31,973 28,715 3,258 — Total assets $ 33,476 $ 30,218 $ 3,258 $ — Accrued Liabilities Accrued liabilities consisted of the following (in thousands): March 31, 2021 December 31, 2020 Accrued research and development expenses $ 2,168 $ 1,375 Accrued compensation 2,480 4,473 Accrued legal expenses 168 651 Other accrued liabilities 1,251 751 Total accrued liabilities $ 6,067 $ 7,250 Revenue Recognition Policy The Company’s revenues generally consist of (i) contract and grant revenue - revenue generated under federal and private foundation grants and contracts, and (ii) collaboration and licensing revenue - revenue related to non-refundable upfront fees, royalties and milestone payments earned under license agreements. Revenue is recognized in accordance with the criteria outlined in Accounting Standards Codification (ASC) 606 issued by the Financial Accounting Standards Board (FASB). Following this accounting pronouncement, a five-step approach is applied for recognizing revenue, including (1) identify the contract with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when, or as, the entity satisfies a performance obligation. Biomedical Advanced Research and Development Authority (BARDA) In February 2011, the Company entered into a contract with BARDA for the advanced development of BCV as a medical countermeasure in the event of a smallpox release. Under the contract, the Company may receive up to $75.8 million in expense reimbursement and $5.3 million in fees over the performance of 1 base segment and 4 option segments. Exercise of each option segment is solely at the discretion of BARDA. The Company assessed the services in accordance with the authoritative guidance and concluded that there is a potential of 5 separate contracts (1 base segment and 4 option segments) within this agreement, each of which has a single performance obligation. At present, all option segments (1 through 4) have been exercised, as well as the base segment. The transaction price for each segment, based on the transaction price as defined in each segment contract, is allocated to the single performance obligation for each contract. The transaction price is recognized over time by measuring the progress toward complete satisfaction of the performance obligation. For reimbursable expenses, this occurs as qualifying research activities are conducted based on invoices from company vendors. For the fixed fee, the progress toward complete satisfaction is estimated based on the costs incurred to date relative to the total estimated costs per the terms of each contract. The Company typically invoices BARDA monthly as costs are incurred. Any amounts received in advance of performance are recorded as deferred revenue until earned. The base segment and first option segment were completed prior to adoption of ASC 606. The Company is currently performing under the fourth option segment of the contract during which the Company may receive up to a total of $4.6 million in expense reimbursement and fees. The second and third option segments were completed on August 20, 2020. The fourth option segment is scheduled to end on September 1, 2021. Grant Revenue Grant revenue under cost-plus-fixed-fee grants from the federal government and private foundations is recognized as allowable costs are incurred and fees are earned. As a result of its acquisition of Oncoceutics, Inc. (Oncoceutics), the Company became the beneficiary of two federal grant programs and two grant programs with private foundations. At March 31, 2021, there is $0.1 million remaining to be funded on the federal grants. At March 31, 2021, the Company has a receivable balance of $0.1 million and a deferred revenue balance of $0.3 million related to these grants. Additionally, for the three months ended March 31, 2021, the Company recognized $0.2 million of grant revenue related to these grants. SymBio Pharmaceuticals On September 30, 2019, the Company entered into a license agreement with SymBio Pharmaceuticals Limited (SymBio) under which the Company granted SymBio exclusive worldwide rights to develop, manufacture and commercialize BCV for all human indications, excluding the prevention and treatment of orthopoxviruses, including smallpox. The Company assessed the agreement in accordance with the authoritative guidance and concluded that the SymBio contract includes multiple performance obligations. The SymBio contract has one fixed transaction amount of a $5.0 million upfront payment received in October 2019 and several variable transaction amounts, up to $180 million, due to the Company at certain regulatory and commercial milestones, along with low double-digit percent royalties based on net sales of BCV. All variable transaction amounts are fully constrained, therefore the allocated transaction price is $5.0 million. The majority of the transaction price of the contract has been allocated to the combined performance obligation of the granting of the license to BCV and associated technology transfer which was recognized when the technology transfer was completed in the fourth quarter of 2019. The revenue from regulatory and commercial milestones and royalties from net sales will be recognized upon the occurrence of the triggering events or when those transaction amounts are no longer fully constrained. Research and Development Prepaids and Accruals As part of the process of preparing financial statements, the Company is required to estimate its expenses resulting from its obligation under contracts with vendors and consultants and clinical site agreements in connection with its research and development efforts. The financial terms of these contracts are subject to negotiations which vary contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate research and development expenses in its financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of its research and development efforts. The Company determines prepaid and accrual estimates through discussion with applicable personnel and outside service providers as to the progress or state of communication of clinical trials, or other services completed. The Company adjusts its rate of research and development expense recognition if actual results differ from its estimates. The Company makes estimates of its prepaid and accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. Through March 31, 2021, there had been no material adjustments to the Company’s prior period estimates of prepaid and accruals for research and development expenses. The Company’s research and development prepaids and accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Basic and Diluted Net Loss Per Share of Common Stock Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during the period, excluding the dilutive effects of non-vested restricted stock, stock options, and employee stock purchase plan purchase rights. Diluted net loss per share of common stock is computed by dividing net loss by the sum of the weighted-average number of shares of common stock outstanding during the period plus the potential dilutive effects of non-vested restricted stock, stock options, and employee stock purchase plan purchase rights outstanding during the period calculated in accordance with the treasury stock method, but are excluded if their effect is anti-dilutive. Because the impact of these items is anti-dilutive during the periods of net loss, there was no difference between basic and diluted loss per share of common stock for the three months ended March 31, 2021 and 2020. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. In addition to estimates discussed in other sections of this Quarterly Report on Form 10-Q, the most significant estimates in the Company’s consolidated financial statements relate to the valuation of stock options and the valuation allowance for deferred tax assets resulting from net operating losses. These estimates are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates. Segments The Company operates in only one segment, pharmaceuticals. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Investments

Investments	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The following tables summarize the Company's debt investments (in thousands): March 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate bonds $ 34,342 $ — $ (32) $ 34,310 U.S. treasury securities 28,614 3 (5) 28,612 Commercial paper 57,533 1 (10) 57,524 Total investments $ 120,489 $ 4 $ (47) $ 120,446 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate bonds $ 3,256 $ 2 $ — $ 3,258 U.S. treasury securities 28,717 1 (3) 28,715 Total investments $ 31,973 $ 3 $ (3) $ 31,973 The following tables summarize the Company's debt investments with unrealized losses, aggregated by investment type and the length of time that individual investments have been in a continuous unrealized loss position (in thousands, except number of securities): March 31, 2021 Less than 12 Months Greater than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 32,066 $ (32) $ — $ — $ 32,066 $ (32) Commercial paper 50,936 (10) — — 50,936 (10) U.S. treasury securities 11,013 (5) — — 11,013 (5) Total $ 94,015 $ (47) $ — $ — $ 94,015 $ (47) Number of securities with unrealized losses 34 — 34 December 31, 2020 Less than 12 Months Greater than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss U.S. treasury securities $ 16,598 $ (3) $ — $ — $ 16,598 $ (3) Total $ 16,598 $ (3) $ — $ — $ 16,598 $ (3) Number of securities with unrealized losses 6 — 6 The Company periodically reviews available-for-sale debt investments for other-than-temporary declines in fair value below the cost basis and whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company evaluates, among other things, the duration and extent to which the fair value of a security is less than its cost; the financial condition of the issuer and any changes thereto; and the Company’s intent to sell, or whether it will more likely than not be required to sell, the security before recovery of its cost basis. At March 31, 2021, the Company did not intend to sell, and was not more likely than not to be required to sell, the available-for-sale debt investments in an unrealized loss position before recovery of the cost basis of the securities, which may be at maturity. There were no such declines in value for the three months ended March 31, 2021 and 2020. Unrealized gains and losses on debt investments are recorded to unrealized (loss) gain on debt investments, net in the Consolidated Statements of Operations and Comprehensive Loss. Realized gains and losses on debt investments are recorded based on specific identification to interest income and other, net in the Consolidated Statements of Operations and Comprehensive Loss. The Company recognizes interest income on an accrual basis in interest income in the Consolidated Statements of Operations and Comprehensive Loss. The following table summarizes the scheduled maturity for the Company's debt investments at March 31, 2021 (in thousands): Maturing in one year or less $ 112,898 Maturing after one year through two years 7,548 Total debt investments $ 120,446

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company leases its facilities under long-term operating leases that expire at various dates through 2026. The Company generally has options to renew lease terms on its facilities, which may be exercised at the Company's sole discretion. In addition, certain lease arrangements may be terminated prior to their original expiration date at the Company's discretion. The Company evaluates renewal and termination options at the lease commencement date to determine if it is reasonably certain to exercise the option and has concluded on all operating leases that it is not reasonably certain that any options will be exercised. The weighted-average remaining lease term for the Company's operating leases as of March 31, 2021 was 4.58 years. Expense related to leases is recorded on a straight-line basis over the lease term. Lease expense under operating leases, including common area maintenance fees, totaled approximately $144,000 and $193,000, respectively, for the three months ended March 31, 2021 and 2020. The discount rate implicit within the Company's leases is generally not determinable and therefore the Company determines the discount rate based on its incremental borrowing rate based on the information available at commencement date. As of March 31, 2021, the operating lease liabilities reflect a weighted-average discount rate of 7.89%. The following table sets forth the operating lease right-of-use assets and liabilities as of March 31, 2021 (in thousands): Assets Operating lease right-of-use assets $ 2,717 Liabilities Operating lease short-term liabilities (recorded within Accrued liabilities) $ 105 Operating lease long-term liabilities (recorded within Lease-related obligations) 2,752 Total operating lease liabilities $ 2,857 Operating lease payments over the remainder of the lease terms are as follows (in thousands): Years Ending December 31, As of March 31, 2021 2021 (1) $ 127 2022 715 2023 736 2024 759 2025 781 All remaining years 467 Total future minimum rental payments $ 3,585 Less amount of lease payments representing interest 728 Total present value of lease payments $ 2,857 (1) The Company entered into the Ninth Amendment of its lease for the Company's headquarters in Durham, North Carolina, which extended the term of the lease by 65 months to July 31, 2026. As part of the amendment, the Company is entitled to receive a rent abatement of the first 5 months of the new lease term which began on March 1, 2021. Additionally, the Ninth Amendment grants the Company a refurbishment allowance, which the Company expects to receive in 2021 after the refurbishment has been completed. As of December 31, 2020, operating lease payments over the remainder of the lease terms were as follows (in thousands): Years Ending December 31, As of December 31, 2020 2021 $ 260 2022 715 2023 736 2024 759 2025 781 Thereafter 467 Total future minimum rental payments $ 3,718 Less amount of lease payments representing interest 792 Total present value of lease payments $ 2,926 For the three months ended March 31, 2021 and 2020, the Company made lease payments of approximately $133,000 and $178,000, respectively. Sublease The Company subleased 3,537 square feet of its office space under a non-cancelable operating lease that expired in February 2021. For the three months ended March 31, 2021 and 2020, the Company recognized approximately $12,000 and $18,000 of income, respectively, in Interest income and other, net on the Consolidated Statement of Operations and Comprehensive Loss. As this lease has terminated, there are no future minimum rentals payments to be received. Significance of Revenue Source The Company is the recipient of federal research contract funds from BARDA, the primary source of the Company's contract and grant revenue. Periodic audits are required under the Company’s BARDA agreement and certain costs may be questioned as appropriate under the BARDA agreement. At March 31, 2021 and December 31, 2020, the Company had recorded a $38,000 provision for potential refundable amounts.

Equity Transactions and Share-b

Equity Transactions and Share-based Compensation	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Equity Transactions and Share-based Compensation	Equity Transactions and Share-based Compensation Common Stock On January 20, 2021, we entered into an underwriting agreement (the Underwriting Agreement) with Jefferies LLC and Cowen and Company, LLC, as representatives of the several underwriters named therein (collectively, the Underwriters), relating to the issuance and sale of 11,765,000 shares (the Shares) of the Company’s common stock, par value $0.001 per share (the Common Stock). The price to the public in this offering was $8.50 per share, and the Underwriters agreed to purchase the Shares from the Company pursuant to the Underwriting Agreement at a price of $7.99 per share. Under the terms of the Underwriting Agreement, the Company granted the Underwriters a 30-day option to purchase up to 1,764,750 additional shares of Common Stock at the public offering price. The net proceeds to the Company from this offering were approximately $107.8 million, as the Underwriters’ option to purchase additional shares was exercised in full, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company. The offering closed on January 25, 2021. Stock Options The Company maintains a 2013 Equity Incentive Plan (the 2013 Plan), which provides for the grant of incentive stock options (ISOs), non-statutory stock options (NSOs), stock appreciation rights, restricted stock awards, restricted stock unit (RSU) awards, performance-based stock awards, and other forms of equity compensation (collectively, stock awards), all of which may be granted to employees, including officers, non-employee directors and consultants of the Company and its affiliates. Additionally, the 2013 Plan provides for the grant of performance cash awards. The number of shares of common stock reserved for future issuance automatically increases on January 1 of each calendar year by 4% of the total number of shares of capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s board of directors. On January 1, 2021, the common stock reserved for issuance under the 2013 Plan was automatically increased by 2.5 million shares. As of March 31, 2021, there was a total of 2.6 million shares reserved for future issuance under the 2013 Plan. The Company issued approximately 710,000 shares of common stock pursuant to the exercise of stock options during the three months ended March 31, 2021. The Company issued no shares of common stock pursuant to the exercise of stock options during the three months ended March 31, 2020. Employee Stock Purchase Plan The Company maintains a 2013 Employee Stock Purchase Plan (ESPP), which provides for the issuance of shares of common stock pursuant to purchase rights granted to the Company’s employees or to employees of any of its designated affiliates. The Company has reserved a total of 3.9 million shares of common stock to be purchased under the ESPP, of which 2.6 million shares remained available for purchase as of March 31, 2021. The number of shares of common stock reserved for issuance automatically increases on January 1 of each calendar year, by the lesser of (a) 1% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, (b) 422,535 shares, or (c) a number determined by the Company’s board of directors that is less than (a) and (b). On January 1, 2021, the common stock reserved for issuance under the ESPP was automatically increased by an additional 422,535 shares. The ESPP provides for an automatic reset feature to start participants on a new twenty-four month participation period in the event that the common stock market value on a purchase date is less than the common stock value on the first day of the twenty-four month offering period. Eligible employees may authorize an amount up to 15% of their salary to purchase common stock at the lower of a 15% discount to the beginning price of their offering period or a 15% discount to the ending price of each six-month purchase interval. The Company issued approximately 260,000 and 177,000 shares of common stock pursuant to the ESPP during the three months ended March 31, 2021 and 2020, respectively. Compensation expense for shares purchased under the ESPP related to the purchase discount and the “look-back” option and were determined using a Black-Scholes option pricing model. Restricted Stock Units The Company has issued RSUs to certain employees which vest based on service criteria. When vested, the RSU represents the right to be issued the number of shares of the Company's common stock that is equal to the number of RSUs granted. The grant date fair value for RSUs is based upon the market price of the Company's common stock on the date of the grant. The fair value is then amortized to compensation expense over the requisite service period or vesting term. The Company issued approximately 169,000 and 163,000 shares of common stock pursuant to the vesting of RSUs during the three months ended March 31, 2021 and 2020, respectively. Stock-based Compensation For awards with only service conditions and graded-vesting features, the Company recognizes compensation expense on a straight-line basis over the requisite service period. Total share-based compensation expense recognized related to stock options, the ESPP and RSUs was as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development expense $ 1,377 $ 740 General and administrative expense 1,207 586 Total share-based compensation expense $ 2,584 $ 1,326

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company estimates an annual effective tax rate of 0% for the year ending December 31, 2021 as the Company incurred losses for the three month period ended March 31, 2021, and is forecasting an estimated net loss for both financial statement and tax purposes for the year ending December 31, 2021. Therefore, no federal or state income taxes are expected and none have been recorded at this time. Income taxes have been accounted for using the liability method in accordance with FASB ASC 740. Due to the Company's history of losses since inception, there is not enough evidence at this time to support that the Company will generate future income of a sufficient amount and nature to utilize the benefits of its net deferred tax assets. Accordingly, the deferred tax assets have been reduced by a full valuation allowance, since the Company cannot currently support that realization of its deferred tax assets is more likely than not. However, the Company feels its deferred tax assets may be used upon the Company becoming profitable. At March 31, 2021, the Company had no unrecognized tax benefits that would reduce the Company’s effective tax rate if recognized.

Significant Agreements

Significant Agreements	3 Months Ended
	Mar. 31, 2021
Revenue Recognition [Abstract]
Significant Agreements	Significant Agreements Biomedical Advanced Research and Development Authority (BARDA) In February 2011, the Company entered into a contract with BARDA for the advanced development of BCV as a medical countermeasure in the event of a smallpox release. Under the contract, BARDA will reimburse the Company, plus pay a fixed fee, for the research and development of BCV as a broad-spectrum therapeutic antiviral for the treatment of smallpox infections. The contract consists of an initial performance period, referred to as the base performance segment, plus up to four extension periods, referred to as option segments, of which all have been exercised. Under the contract as currently in effect, the Company may receive up to $75.8 million in expense reimbursement and $5.3 million in fees. The Company is currently performing under the fourth option segment of the contract during which the Company may receive up to a total of $4.6 million in expense reimbursement and fees. The second and third option segments were completed on August 20, 2020. The fourth option segment is scheduled to end on September 1, 2021. Of the $75.8 million in expense reimbursement and $5.3 million in fees that the Company may receive, approximately $78.9 million in expense reimbursement and fees has been awarded. As of March 31, 2021, of the total funding the Company had invoiced an aggregate of $76.7 million with respect to the base performance segment and the four option segments. For the three months ended March 31, 2021 and 2020, the Company recognized revenue under this contract of $1.2 million and $1.2 million, respectively. Cantex Pharmaceuticals, Inc. On July 26, 2019, the Company entered into a License and Development Agreement with Cantex Pharmaceuticals, Inc. (Cantex) pursuant to which the Company acquired exclusive worldwide rights to develop and commercialize, for any and all uses, a glycosaminoglycan compound known as DSTAT, which is currently being studied for the treatment of acute myeloid leukemia and acute lung injury in patients with COVID-19. Under the terms of the license agreement, the Company is responsible for, and bear the future costs of, worldwide development and commercialization of DSTAT. In connection with the transaction, Cantex assigned to the Company all of its rights under its DSTAT supply agreements, including its bulk API agreement with Scientific Protein Laboratories LLC (SPL), including subsequent amendments, pursuant to which SPL will exclusively produce DSTAT for the Company through December 2040. The license agreement obligates the Company to pay Cantex regulatory milestone payments of up to $202.5 million upon receipt of product approvals in the United States, the European Union and Japan, and sales milestone payments of up to $385.0 million upon achievement of specified net sales levels. The Company also agreed to pay Cantex tiered royalties based on percentages of net sales beginning at 10% and not to exceed the high-teens. SymBio Pharmaceuticals On September 30, 2019, the Company entered into a license agreement with SymBio under which the Company granted SymBio exclusive worldwide rights to develop, manufacture and commercialize BCV for all human indications, excluding the prevention and treatment of orthopoxviruses, including smallpox. Under the terms of the license agreement, SymBio will be responsible for, and bear the future costs of, worldwide development and commercialization of BCV in the licensed indications. Either party may terminate the license agreement upon the occurrence of a material breach by the other party (subject to standard cure periods). SymBio may also terminate the license agreement without cause on a country-by-country basis upon ninety days' prior notice. In exchange for the license to SymBio under the Company's BCV rights, the Company received an upfront payment of $5.0 million in October 2019. In addition, the Company is eligible to receive up to $180.0 million in clinical, regulatory and commercial milestones worldwide, as well as low double-digit percent royalties based on net sales of BCV. Since entering into the license agreement in September 2019, the Company has recognized all of the $5.0 million upfront payment.

Oncoceutics Acquisition

Oncoceutics Acquisition	3 Months Ended
	Mar. 31, 2021
Asset Acquisition [Abstract]
Oncoceutics Acquisition	Oncoceutics Acquisition On January 7, 2021, the Company, Ocean Merger Sub, Inc., a Delaware corporation and wholly-owned subsidiary of the Company (Merger Sub), Oncoceutics, Inc., a Delaware corporation (Oncoceutics), and Fortis Advisors, LLC solely in its capacity as representative of the securityholders of Oncoceutics (the Securityholders’ Representative), entered into an Agreement and Plan of Merger (the Merger Agreement). Concurrently with the execution of the Merger Agreement, Merger Sub merged with and into Oncoceutics (the Merger) whereupon the separate corporate existence of Merger Sub ceased, with Oncoceutics continuing as the surviving corporation of the Merger as a wholly-owned subsidiary of the Company. As consideration for the Merger, the Company (a) paid an upfront cash payment of approximately $25.0 million, subject to certain customary adjustments, (b) issued an aggregate of 8,723,769 shares of the Company's common stock, (c) issued a promissory note to the Securityholders' Representative in the principal amount of $14.0 million (the Seller Note), to be paid in cash, subject to the terms and conditions of the Merger Agreement and the Seller Note, upon the one year anniversary of the closing of the Merger, and (d) agreed to make contingent payments up to an aggregate of $360.0 million based on the achievement of certain development, regulatory and commercialization events as set forth in the Merger Agreement, as well as additional tiered royalty payments based upon future net sales of ONC 201 and ONC 206 products, subject to certain reductions as set forth in the Merger Agreement, and a contingent payment in the event the Company receives any proceeds from the sale of a rare pediatric disease priority review voucher based on Oncoceutics' products. The closing payment may be adjusted after the closing, pursuant to procedures set forth in the Merger Agreement, in connection with the finalization of the cash, transaction expenses, debt and working capital amounts at closing. As of March 31, 2021, the Company has recorded an estimated liability of $0.2 million related to closing payment adjustments. This amount may be further adjusted based on final review from both parties. The Company accounted for the Oncoceutics acquisition as an asset acquisition as the majority of the value of the assets acquired related to the ONC201 acquired in-process research and development (IPR&D) asset. In accordance with Accounting Standards Codification, or ASC, Subtopic 730-10-25, Accounting for Research and Development Costs, the up-front payments to acquire a new drug compound, as well as future milestone payments when paid or payable, are immediately expensed as acquired IPR&D in transactions other than a business combination provided that the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no alternative future use. Therefore, the portion of the purchase price that was allocated to the IPR&D assets acquired was immediately expensed. Other assets acquired and liabilities assumed, were recorded at fair value. The following represents the consideration paid and purchase price allocation for the acquisition of Oncoceutics (in thousands, except for per share data): Cash $ 23,836 One-year closing anniversary payment 14,000 Shares common stock issued as consideration 8,723,769 Stock price per share on effective date 4.98 Value of estimated common stock consideration 43,445 Total consideration $ 81,281 Net assets acquired $ (1,310) IPR&D assets expensed 82,591 Total purchase price allocated $ 81,281 Transaction costs expensed to IPR&D (1) $ 299 Total IPR&D expensed $ 82,890

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsThe Company has evaluated subsequent events through the issuance date of these financial statements to ensure that this filing includes appropriate disclosure of events both recognized in the financial statements as of March 31, 2021, and events which occurred subsequently but were not recognized in the financial statements.

The Business and Summary of S_2

The Business and Summary of Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s audited financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of the Company’s management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented have been included. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the full year, for any other interim period or for any future year.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of certain financial instruments, including accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short-term nature of such instruments. For assets and liabilities recorded at fair value, it is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements, in accordance with the fair value hierarchy. Fair value measurements for assets and liabilities where there exists limited or no observable market data are based primarily upon estimates and are often calculated based on the economic and competitive environment, the characteristics of the asset or liability and other factors. Therefore, fair value measurements cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there may be inherent weaknesses in any calculation technique and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the calculated current or future fair values. The Company utilizes fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. The Company groups assets and liabilities at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. The determination of where an asset or liability falls in the hierarchy requires significant judgment. These levels are: • Level 1 — Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2 — Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and models for which all significant inputs are observable, either directly or indirectly. • Level 3 — Valuations based on inputs that are unobservable and significant to the overall fair value measurement. At March 31, 2021 and December 31, 2020, the Company had cash equivalents including money market funds, whose value is based on quoted market prices. At March 31, 2021 and December 31, 2020, the Company had short-term investments, including U.S. Treasury securities, whose value is based on quoted market prices. At March 31, 2021, the Company had long-term investments including U.S. Treasury securities, whose value is based on quoted market prices. Accordingly, these securities are classified as Level 1. At March 31, 2021, the Company had short-term investments, including commercial paper and corporate bonds and on December 31, 2020, the Company had short-term investments including corporate bonds. At March 31, 2021, the Company had long-term investments including U.S. Treasury securities. As quoted prices are not available for these securities, they are valued using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security’s credit rating, prepayment assumptions and other factors such as credit loss assumptions. Accordingly, these securities are classified as Level 2. There was no material re-measurement to fair value of financial assets and liabilities that are not measured at fair value on a recurring basis. For additional information regarding the Company's investments, please refer to Note 2, "Investments."
Revenue Recognition	Revenue Recognition Policy
Research and Development Prepaids and Accruals	Research and Development Prepaids and Accruals As part of the process of preparing financial statements, the Company is required to estimate its expenses resulting from its obligation under contracts with vendors and consultants and clinical site agreements in connection with its research and development efforts. The financial terms of these contracts are subject to negotiations which vary contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate research and development expenses in its financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of its research and development efforts. The Company determines prepaid and accrual estimates through discussion with applicable personnel and outside service providers as to the progress or state of communication of clinical trials, or other services completed. The Company adjusts its rate of research and development expense recognition if actual results differ from its estimates. The Company makes estimates of its prepaid and accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. Through March 31, 2021, there had been no material adjustments to the Company’s prior period estimates of prepaid and accruals for research and development expenses. The Company’s research and development prepaids and accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors.
Basic and Diluted Net Loss Per Share of Common Stock	Basic and Diluted Net Loss Per Share of Common Stock Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during the period, excluding the dilutive effects of non-vested restricted stock, stock options, and employee stock purchase plan purchase rights. Diluted net loss per share of common stock is computed by dividing net loss by the sum of the weighted-average number of shares of common stock outstanding during the period plus the potential dilutive effects of non-vested restricted stock, stock options, and employee stock purchase plan purchase rights outstanding during the period calculated in accordance with the treasury stock method, but are excluded if their effect is anti-dilutive. Because the impact of these items is anti-dilutive during the periods of net loss, there was no difference between basic and diluted loss per share of common stock for the three months ended March 31, 2021 and 2020.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. In addition to estimates discussed in other sections of this Quarterly Report on Form 10-Q, the most significant estimates in the Company’s consolidated financial statements relate to the valuation of stock options and the valuation allowance for deferred tax assets resulting from net operating losses. These estimates are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.
Segments	SegmentsThe Company operates in only one segment, pharmaceuticals.
Impact of Recently Issued Accounting Standards and Impact of Recently Adopted Accounting Standards	Impact of Recently Issued Accounting Standards In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

The Business and Summary of S_3

The Business and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of certain assets measured at fair value on a recurring basis	Below are tables that present information about certain assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements March 31, 2021 Total Quoted Prices in Significant Other Significant Cash equivalents Money market funds $ 26,990 $ 26,990 $ — $ — Total cash equivalents 26,990 26,990 — — Short-term investments U.S. treasury securities 21,064 21,064 — — Commercial paper 57,524 — 57,524 — Corporate bonds 34,310 — 34,310 — Total short-term investments 112,898 21,064 91,834 — Long-term investments U.S. treasury securities 7,548 2,553 4,995 — Total long-term investments 7,548 2,553 4,995 — Total assets $ 147,436 $ 50,607 $ 96,829 $ — Fair Value Measurements December 31, 2020 Total Quoted Prices in Significant Other Significant Cash equivalents Money market funds $ 1,503 $ 1,503 $ — $ — Total cash equivalents 1,503 1,503 — — Short-term investments U.S. treasury securities 28,715 28,715 — — Corporate bonds 3,258 — 3,258 — Total short-term investments 31,973 28,715 3,258 — Total assets $ 33,476 $ 30,218 $ 3,258 $ —
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands): March 31, 2021 December 31, 2020 Accrued research and development expenses $ 2,168 $ 1,375 Accrued compensation 2,480 4,473 Accrued legal expenses 168 651 Other accrued liabilities 1,251 751 Total accrued liabilities $ 6,067 $ 7,250

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of short-term and long-term investments	The following tables summarize the Company's debt investments (in thousands): March 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate bonds $ 34,342 $ — $ (32) $ 34,310 U.S. treasury securities 28,614 3 (5) 28,612 Commercial paper 57,533 1 (10) 57,524 Total investments $ 120,489 $ 4 $ (47) $ 120,446 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate bonds $ 3,256 $ 2 $ — $ 3,258 U.S. treasury securities 28,717 1 (3) 28,715 Total investments $ 31,973 $ 3 $ (3) $ 31,973
Summary of investments with unrealized losses, aggregated by investment type and the length of time	The following tables summarize the Company's debt investments with unrealized losses, aggregated by investment type and the length of time that individual investments have been in a continuous unrealized loss position (in thousands, except number of securities): March 31, 2021 Less than 12 Months Greater than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 32,066 $ (32) $ — $ — $ 32,066 $ (32) Commercial paper 50,936 (10) — — 50,936 (10) U.S. treasury securities 11,013 (5) — — 11,013 (5) Total $ 94,015 $ (47) $ — $ — $ 94,015 $ (47) Number of securities with unrealized losses 34 — 34 December 31, 2020 Less than 12 Months Greater than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss U.S. treasury securities $ 16,598 $ (3) $ — $ — $ 16,598 $ (3) Total $ 16,598 $ (3) $ — $ — $ 16,598 $ (3) Number of securities with unrealized losses 6 — 6
Summary of the scheduled maturity of company investments	The following table summarizes the scheduled maturity for the Company's debt investments at March 31, 2021 (in thousands): Maturing in one year or less $ 112,898 Maturing after one year through two years 7,548 Total debt investments $ 120,446

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating Lease Right-of-Use Assets and Liabilities	The following table sets forth the operating lease right-of-use assets and liabilities as of March 31, 2021 (in thousands): Assets Operating lease right-of-use assets $ 2,717 Liabilities Operating lease short-term liabilities (recorded within Accrued liabilities) $ 105 Operating lease long-term liabilities (recorded within Lease-related obligations) 2,752 Total operating lease liabilities $ 2,857
Operating Lease Maturity	Operating lease payments over the remainder of the lease terms are as follows (in thousands): Years Ending December 31, As of March 31, 2021 2021 (1) $ 127 2022 715 2023 736 2024 759 2025 781 All remaining years 467 Total future minimum rental payments $ 3,585 Less amount of lease payments representing interest 728 Total present value of lease payments $ 2,857 (1) The Company entered into the Ninth Amendment of its lease for the Company's headquarters in Durham, North Carolina, which extended the term of the lease by 65 months to July 31, 2026. As part of the amendment, the Company is entitled to receive a rent abatement of the first 5 months of the new lease term which began on March 1, 2021. Additionally, the Ninth Amendment grants the Company a refurbishment allowance, which the Company expects to receive in 2021 after the refurbishment has been completed. As of December 31, 2020, operating lease payments over the remainder of the lease terms were as follows (in thousands): Years Ending December 31, As of December 31, 2020 2021 $ 260 2022 715 2023 736 2024 759 2025 781 Thereafter 467 Total future minimum rental payments $ 3,718 Less amount of lease payments representing interest 792 Total present value of lease payments $ 2,926

Equity Transactions and Share_2

Equity Transactions and Share-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of employee and non-employee share-based compensation expense recognized related to stock options, the ESPP and RSUs	Total share-based compensation expense recognized related to stock options, the ESPP and RSUs was as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development expense $ 1,377 $ 740 General and administrative expense 1,207 586 Total share-based compensation expense $ 2,584 $ 1,326

Oncoceutics Acquisition (Tables

Oncoceutics Acquisition (Tables)	3 Months Ended
	Mar. 31, 2021
Asset Acquisition [Abstract]
Asset Acquisition	The following represents the consideration paid and purchase price allocation for the acquisition of Oncoceutics (in thousands, except for per share data): Cash $ 23,836 One-year closing anniversary payment 14,000 Shares common stock issued as consideration 8,723,769 Stock price per share on effective date 4.98 Value of estimated common stock consideration 43,445 Total consideration $ 81,281 Net assets acquired $ (1,310) IPR&D assets expensed 82,591 Total purchase price allocated $ 81,281 Transaction costs expensed to IPR&D (1) $ 299 Total IPR&D expensed $ 82,890

The Business and Summary of S_4

The Business and Summary of Significant Accounting Policies - Narrative (Details)	3 Months Ended
	Mar. 31, 2021segmentproduct_candidate
Accounting Policies [Abstract]
Number of product candidates | product_candidate	3
Number of segments | segment	1

The Business and Summary of S_5

The Business and Summary of Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	$ 112,898	$ 31,973
Long-term investments	7,548	0
Fair value, measurements, recurring
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	26,990	1,503
Short-term investments, available-for-sale	112,898	31,973
Long-term investments	7,548
Total assets	147,436	33,476
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	26,990	1,503
Short-term investments, available-for-sale	21,064	28,715
Long-term investments	2,553
Total assets	50,607	30,218
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	0	0
Short-term investments, available-for-sale	91,834	3,258
Long-term investments	4,995
Total assets	96,829	3,258
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	0	0
Short-term investments, available-for-sale	0	0
Long-term investments	0
Total assets	0	0
Money market funds | Fair value, measurements, recurring
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	26,990	1,503
Money market funds | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	26,990	1,503
Money market funds | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	0	0
Money market funds | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Separate Account Investment [Line Items]
Cash equivalents	0	0
U.S. treasury securities | Fair value, measurements, recurring
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	21,064	28,715
U.S. treasury securities | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	21,064	28,715
U.S. treasury securities | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	0	0
U.S. treasury securities | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	0	0
Commercial paper | Fair value, measurements, recurring
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	57,524
Commercial paper | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	0
Commercial paper | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	57,524
Commercial paper | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	0
Corporate bonds | Fair value, measurements, recurring
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	34,310	3,258
Corporate bonds | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	0	0
Corporate bonds | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	34,310	3,258
Corporate bonds | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Separate Account Investment [Line Items]
Short-term investments, available-for-sale	$ 0	$ 0

The Business and Summary of S_6

The Business and Summary of Significant Accounting Policies - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Accrued research and development expenses	$ 2,168	$ 1,375
Accrued compensation	2,480	4,473
Accrued legal expenses	168	651
Other accrued liabilities	1,251	751
Total accrued liabilities	$ 6,067	$ 7,250

The Business and Summary of S_7

The Business and Summary of Significant Accounting Policies - Revenue Recognition (Details)	1 Months Ended	3 Months Ended		122 Months Ended	127 Months Ended
	Sep. 30, 2019USD ($)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2021USD ($)	Sep. 01, 2021USD ($)optionSegmentbaseSegmentrevenueContract	Jan. 07, 2021grant	Sep. 30, 2020USD ($)	Oct. 31, 2019USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues		$ 1,435,000	$ 1,241,000
Oncoceutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining grant to be received		100,000		$ 100,000
Grant | Oncoceutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues		200,000
Grant receivable		100,000		100,000
Deferred revenue		300,000		300,000
BARDA
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues		$ 1,200,000	$ 1,200,000	$ 76,700,000
BARDA | Scenario, Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues					$ 78,900,000
Total number of base segments | baseSegment					1
Total number of option segments | optionSegment					4
Total number of separate contracts | revenueContract					5
BARDA | Expense reimbursement | Scenario, Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues					$ 75,800,000
BARDA | Fees | Scenario, Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues					5,300,000
BARDA Fourth Option Segment | Scenario, Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues					$ 4,600,000
Federal Goverment | Oncoceutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of grants | grant						2
Private Foundations | Oncoceutics, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of grants | grant						2
SymBio Pharmaceuticals
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 5,000,000
Initial upfront payment to be received							$ 5,000,000	$ 5,000,000
Payment to be received upon achievement of milestones	$ 180,000,000						$ 180,000,000

Investments - Summary of Availa

Investments - Summary of Available-for-Sale securities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of Investments [Line Items]
Amortized Cost	$ 120,489	$ 31,973
Gross Unrealized Gains	4	3
Gross Unrealized Losses	(47)	(3)
Estimated Fair Value	120,446	31,973
Corporate bonds
Schedule of Investments [Line Items]
Amortized Cost	34,342	3,256
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(32)	0
Estimated Fair Value	34,310	3,258
U.S. treasury securities
Schedule of Investments [Line Items]
Amortized Cost	28,614	28,717
Gross Unrealized Gains	3	1
Gross Unrealized Losses	(5)	(3)
Estimated Fair Value	28,612	$ 28,715
Commercial paper
Schedule of Investments [Line Items]
Amortized Cost	57,533
Gross Unrealized Gains	1
Gross Unrealized Losses	(10)
Estimated Fair Value	$ 57,524

Investments - Summary of Invest

Investments - Summary of Investments with Unrealized Losses, Aggregated by Investment Type and the Length of Time (Details) $ in Thousands	Mar. 31, 2021USD ($)security	Dec. 31, 2020USD ($)security
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	$ 94,015	$ 16,598
Unrealized loss, less than 12 months	(47)	(3)
Fair value, greater than 12 months	0	0
Unrealized loss, greater than 12 months	0	0
Fair value, total	94,015	16,598
Unrealized loss, total	$ (47)	$ (3)
Number of securities with unrealized losses, less than 12 months | security	34	6
Number of securities with unrealized losses, greater than 12 months | security	0	0
Number of securities with unrealized losses, total | security	34	6
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	$ 32,066
Unrealized loss, less than 12 months	(32)
Fair value, greater than 12 months	0
Unrealized loss, greater than 12 months	0
Fair value, total	32,066
Unrealized loss, total	(32)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	50,936
Unrealized loss, less than 12 months	(10)
Fair value, greater than 12 months	0
Unrealized loss, greater than 12 months	0
Fair value, total	50,936
Unrealized loss, total	(10)
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	11,013	$ 16,598
Unrealized loss, less than 12 months	(5)	(3)
Fair value, greater than 12 months	0	0
Unrealized loss, greater than 12 months	0	0
Fair value, total	11,013	16,598
Unrealized loss, total	$ (5)	$ (3)

Investments - Schedule of Inves

Investments - Schedule of Investment Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Maturing in one year or less	$ 112,898
Maturing after one year through two years	7,548
Total debt investments	$ 120,446	$ 31,973

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)ft²	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Weighted average remaining lease term	4 years 6 months 29 days
Rent expense under non-cancelable operating leases	$ 144	$ 193
Weighted average discount rate	7.89%
Lease payments	$ 133	178
Area of sublease space (in sq ft) | ft²	3,537
Sublease income	$ 12	$ 18
BARDA | Refundable Agreements
Disaggregation of Revenue [Line Items]
Provision for refundable amounts	$ 38		$ 38

Commitments and Contingencies_2

Commitments and Contingencies - Operating Lease Right-of-Use Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Operating lease right-of-use assets	$ 2,717	$ 2,825
Liabilities
Operating lease short-term liabilities (recorded within Accrued liabilities)	105
Operating lease long-term liabilities (recorded within Lease-related obligations)	2,752	2,814
Total present value of lease payments	$ 2,857	$ 2,926
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent

Commitments and Contingencies_3

Commitments and Contingencies - Maturity Analysis of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of fiscal year	$ 127
Year one	715	$ 260
Year two	736	715
Year three	759	736
Year four	781	759
Year five		781
All remaining years	467
Thereafter		467
Total future minimum rental payments	3,585	3,718
Less amount of lease payments representing interest	728	792
Total present value of lease payments	$ 2,857	$ 2,926
Lease extension term	65 months
Rent abatement term	5 months

Equity Transactions and Share_3

Equity Transactions and Share-based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 20, 2021	Jan. 01, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value (in dollars per share)	$ 0.001		$ 0.001		$ 0.001
Shares issued for restricted stock units (in shares)			169,000	163,000
Public Stock Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares sold (in shares)	11,765,000
Price of shares sold (in USD per share)	$ 8.50
Proceeds from shares sold	$ 107.8
Underwriter's Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares sold (in shares)	1,764,750
Price of shares sold (in USD per share)	$ 7.99
Purchase option term	30 days
The 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Evergreen option provision, equity increase			4.00%
Additional shares authorized (in shares)		2,500,000
Number of shares reserved for future issuance (in shares)			2,600,000
Shares issued pursuant to the exercise of stock options (in shares)			710,000	0
The 2013 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Evergreen option provision, equity increase			1.00%
Additional shares authorized (in shares)		422,535
Number of shares reserved for future issuance (in shares)			2,600,000
Number of shares authorized to be granted (in shares)			3,900,000
Number of shares reserved for issuance, annual increase (in shares)			422,535
Participation term			24 months
Percentage of pay that employee can contribute, maximum			15.00%
Discounted purchase price from market price, offering date			15.00%
Discounted purchase price from market price, purchase date			15.00%
Purchase interval			6 months
Shares issued pursuant to employee stock purchase plan (in shares)			260,000	177,000

Equity Transactions and Share_4

Equity Transactions and Share-based Compensation - Schedule of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 2,584	$ 1,326
Research and development expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	1,377	740
General and administrative expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 1,207	$ 586

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021
Income Tax Contingency [Line Items]
Federal or state income taxes	$ 0
Unrecognized tax benefits	$ 0
Scenario, Forecast
Income Tax Contingency [Line Items]
Estimated annual effective tax rate		0.00%

Significant Agreements (Details

Significant Agreements (Details)	1 Months Ended		3 Months Ended		122 Months Ended	127 Months Ended
	Sep. 30, 2019USD ($)	Feb. 28, 2011extension	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2021USD ($)	Sep. 01, 2021USD ($)	Sep. 30, 2020USD ($)	Oct. 31, 2019USD ($)	Jul. 26, 2019USD ($)
Long-term Purchase Commitment [Line Items]
Total revenues			$ 1,435,000	$ 1,241,000
BARDA
Long-term Purchase Commitment [Line Items]
Number of extension periods | extension		4
Total revenues			$ 1,200,000	$ 1,200,000	$ 76,700,000
Cantex Pharmaceuticals Inc.
Long-term Purchase Commitment [Line Items]
Payments to be made for regulatory milestones (up to)									$ 202,500,000
Payments to be made upon achievement of specified net sales levels (up to)									$ 385,000,000
Royalty percentage to be paid (at least)									10.00%
SymBio Pharmaceuticals
Long-term Purchase Commitment [Line Items]
Total revenues	$ 5,000,000
Termination notice period	90 days
Initial upfront payment to be received							$ 5,000,000	$ 5,000,000
Payment to be received upon achievement of milestones	$ 180,000,000						$ 180,000,000
Scenario, Forecast | BARDA
Long-term Purchase Commitment [Line Items]
Total revenues						$ 78,900,000
Scenario, Forecast | BARDA | Expense reimbursement
Long-term Purchase Commitment [Line Items]
Total revenues						75,800,000
Scenario, Forecast | BARDA | Fees
Long-term Purchase Commitment [Line Items]
Total revenues						5,300,000
Scenario, Forecast | BARDA Fourth Option Segment
Long-term Purchase Commitment [Line Items]
Total revenues						$ 4,600,000

Oncoceutics Acquisition - Narra

Oncoceutics Acquisition - Narrative (Details) - Oncoceutics, Inc. $ in Thousands	Jan. 07, 2021USD ($)shares
Asset Acquisition [Line Items]
Cash payment for acquisition	$ 25,000
Number of shares issued for acquisition | shares	8,723,769
Debt issued for acquisition	$ 14,000
Contingent consideration for acquisition	360,000
Liability for closing payment adjustments	$ 200

Oncoceutics Acquisition - Consi

Oncoceutics Acquisition - Consideration Paid and Purchase Price Allocation (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 07, 2021	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Asset Acquisition [Line Items]
Acquired in-process research and development		$ 82,890		$ 0
Oncoceutics, Inc.
Asset Acquisition [Line Items]
Cash	$ 23,836
One-year closing anniversary payment	$ 14,000
Shares common stock issued as consideration (in shares)	8,723,769
Stock price per share on effective date (in USD per share)	$ 4.98
Value of estimated common stock consideration	$ 43,445
Total consideration	81,281
Net assets acquired	(1,310)
Acquired in-process research and development	82,591
Total purchase price allocated	81,281
Transaction costs expensed to IPR&D	299
Transaction costs expensed to IPR&D	$ 82,890
Transaction expenses			$ 600