Humanigen (HGENQ) 10-K 10 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 05, 2021	Jun. 30, 2020
Document and Entity Information
Entity Registrant Name	HUMANIGEN, INC
Entity Central Index Key	0001293310
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Shell Company	false
Auditor Attestation Flag	false
Entity Emerging Growth Company	false
Entity Incorporation State Code	DE
Entity File Number	001-35798
Entity Public Float			$ 370,406,889
Entity Common Stock, Shares Outstanding		53,482,364

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 67,737	$ 143
Prepaid expenses and other current assets	475	309
Total current assets	68,212	452
Intangible assets	20
Restricted cash	70	71
Total assets	68,302	523
Current liabilities:
Accounts payable	13,078	5,046
Accrued expenses	5,463	3,308
Deferred revenue - current	1,874
Bridge notes		2,113
Convertible notes - current		2,033
Notes payable to vendors		1,094
Total current liabilities	20,415	13,594
Non-current liabilities:
Deferred revenue - non-current	2,342
Convertible notes - non current		1,247
Total non-current liabilities:	2,342	1,247
Total liabilities	22,757	14,841
Stockholders' equity (deficit):
Common stock, $0.001 par value: 225,000,000 shares authorized at December 31, 2020 and December 31, 2019; 51,626,508 and 22,806,890 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	52	22
Additional paid-in capital	419,923	270,555
Accumulated deficit	(374,430)	(284,895)
Total stockholders' equity (deficit)	45,545	(14,318)
Total liabilities and stockholders' equity (deficit)	$ 68,302	$ 523

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Sep. 11, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001		$ 0.001
Common stock, shares authorized	225,000,000	225,000,000	225,000,000
Common stock, shares issued	51,626,508		22,806,890
Common stock, shares outstanding	51,626,508		22,806,890

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Total revenue	$ 312
Operating expenses:
Research and development	72,713	2,616
Selling, general and administrative	15,797	6,328
Total operating expenses	88,510	8,944
Loss from operations	(88,198)	(8,944)
Other expense:
Interest expense	(1,336)	(1,349)
Other expense, net	(1)	(1)
Net loss	$ (89,535)	$ (10,294)
Basic and diluted net loss per common share	$ (2.42)	$ (0.46)
Weighted average common shares outstanding used to calculate basic and diluted net loss per common share	36,963,030	22,361,250
License revenue [Member]
Revenue:
Total revenue	$ 312

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2018	$ 22	$ 266,469	$ (274,601)	$ (8,110)
Balances (in shares) at Dec. 31, 2018	21,979,506
Issuance of common stock in exchange for services		83		83
Issuance of common stock in exchange for services (in shares)	21,972
Issuance of stock options for payment of compensation		207		207
Issuance of common stock for payment of compensation		137		137
Issuance of common stock for payment of compensation, shares	30,445
Issuance of warrant for services
Issuance of common stock upon option exercise		325		325
Issuance of common stock upon option exercise, shares	97,725
Convertible note beneficial conversion feature		143		143
Conversion of advance notes		981		981
Conversion of advance notes, shares	435,924
Issuance of common stock in connection with equity line of credit		185		185
Issuance of common stock in connection with equity line of credit, shares	241,318
Stock-based compensation expense		2,025		2,025
Net loss			(10,294)	(10,294)
Balances at Dec. 31, 2019	$ 22	270,555	(284,895)	(14,318)
Balances (in shares) at Dec. 31, 2019	22,806,890
Issuance of common stock, net of expenses	$ 27	139,733		139,760
Issuance of common stock, net of expenses, shares	25,745,744
Issuance of common stock for conversion of debt	$ 3	4,313		4,316
Issuance of common stock for conversion of debt, shares	2,397,916
Issuance of common stock in exchange for services		302		302
Issuance of common stock in exchange for services (in shares)	45,064
Issuance of stock options for payment of compensation		180		180
Issuance of common stock for payment of compensation		78		78
Issuance of common stock for payment of compensation, shares	17,317
Issuance of warrant for services		2,070		2,070
Issuance of common stock upon option exercise		572		572
Issuance of common stock upon option exercise, shares	390,668
Issance of common stock upon warrant exercise		10		10
Issance of common stock upon warrant exercise, shares	222,909
Stock-based compensation expense		2,110		2,110
Net loss			(89,535)	(89,535)
Balances at Dec. 31, 2020	$ 52	$ 419,923	$ (374,430)	$ 45,545
Balances (in shares) at Dec. 31, 2020	51,626,508

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (89,535)	$ (10,294)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation expense	2,110	2,025
Issuance of common stock for payment of compensation	78	137
Issuance of common stock in exchange for services	302	83
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(166)	176
Accounts payable	8,032	2,190
Accrued expenses	9,326	1,682
Net cash used in operating activities	(69,853)	(4,001)
Investing activities:
Purchase of intangible assets	(20)
Net cash used in investing activities	(20)
Financing activities:
Net proceeds from issuance of common stock	139,760	185
Proceeds from exercise of stock options	572	325
Proceeds from exercise of warrants	10
Net proceeds from issuance of convertible notes	467	1,275
Net proceeds from issuance of PPP loan	83
Net proceeds from issuance of bridge notes	350	2,050
Payments on PPP loan	(83)
Payments on bridge notes	(2,400)
Payments on convertible notes	(518)
Payments on notes payable to vendors	(775)	(505)
Net cash provided by financing activities	137,466	3,330
Net increase (decrease) in cash, cash equivalents and restricted cash	67,593	(671)
Cash, cash equivalents and restricted cash, beginning of period	214	885
Cash, cash equivalents and restricted cash, end of period	67,807	214
Supplemental cash flow disclosure:
Cash paid for interest	672	13
Supplemental disclosure of non-cash investing and financing activities:
Conversion of notes payable and related accrued interest and fees to common stock	4,316	981
Beneficial conversion feature of convertible notes		143
Issuance of stock options in lieu of cash compensation	180	207
Issuance of warrants for services	$ 2,070

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Description of the Business Humanigen, Inc. (the “Company”) was incorporated on March 15, 2000 in California and reincorporated as a Delaware corporation in September 2001 under the name KaloBios Pharmaceuticals, Inc. Effective August 7, 2017, the Company changed its legal name to Humanigen, Inc. The Company is a clinical stage biopharmaceutical company, developing its portfolio of immuno-oncology and immunology monoclonal antibodies. The Company is focusing its efforts on the development of its lead product candidate, lenzilumab™, its proprietary Humaneered® (“Humaneered”) anti-human granulocyte-macrophage colony-stimulating factor (“GM-CSF”) monoclonal antibody. Lenzilumab is a monoclonal antibody that has been demonstrated in animal models to neutralize GM-CSF, a cytokine that we believe is of critical importance in the hyperinflammatory cascade, sometimes referred to as cytokine release syndrome (“CRS”) or cytokine storm, associated with COVID-19, chimeric antigen receptor T-cell (“CAR-T”) therapy and acute Graft versus Host Disease (“GvHD”) associated with bone marrow transplants. GM-CSF neutralization with lenzilumab has been shown to reduce downstream inflammatory cytokines, prevent CRS and reduce its associated neurologic toxicities in-vivo Lenzilumab has completed full enrollment in a Phase 3, multi-center, double-blind, placebo-controlled potential registrational trial for hospitalized, hypoxic patients with COVID-19 pneumonia. If the data from the trial are favorable, based on the Company’s discussions with the U.S. Food and Drug Administration (“FDA”), including a Type B meeting, and in consultation with the regulatory experts at Operation Warp Speed, the Company plans on filing an Emergency Use Authorization (“EUA”) application in the second quarter of 2021. If the EUA is granted, the Company could begin to commercialize lenzilumab for the treatment of hospitalized COVID-19 pneumonia patients. The Company also intends to file a Biologics License Application (“BLA”) in 2021, again assuming the data from the Phase 3 trial are favorable and support such an application. Based on discussions with FDA, the Company understands that a BLA will require it to generate and present more clinical and manufacturing data than would be required to support an EUA. If the ACTIV-5/BET study described below is successful and completed on a timely basis, the Company plans to include the results in its BLA filing. COVID-19 infections are widespread and as of February 26, 2021 in the United States, there were over 28 million cases, nearly 1.8 million hospitalizations and over 510 thousand deaths.. Several vaccines have been developed which show efficacy in excess of 90%, however the slow rollout of inoculations and the emergence of numerous COVID-19 variants lead us to believe the need for therapeutics to treat COVID-19 currently exists and will continue to exist. Lenzilumab has been selected to be part of the ACTIV-5 “Big Effect Trial” (ACTIV-5/BET NCT 04583969). This study is sponsored by the National Institutes of Health (“NIH”). ACTIV-5/BET is designed to determine whether certain approved therapies or investigational drugs in late-stage clinical development show promise against COVID-19 and, therefore, merit advancement into larger clinical trials. ACTIV-5/BET, currently has 17 active U.S. sites enrolling and is expected to enroll in up to 40 U.S. sites, will evaluate lenzilumab with remdesivir, compared to placebo and remdesivir, in hospitalized COVID-19 patients, with approximately 100 patients expected to be assigned to each study arm. The Company is providing lenzilumab for the study, which is fully funded by NIH. Lenzilumab is also being studied in a multicenter phase 1b/2 potential registrational trial as a sequenced therapy with Yescarta® (axicabtagene ciloleucel) to reduce CRS and neurotoxicity in patients with relapsed or refractory diffuse large B-cell lymphoma (“DLBCL”) (NCT 04314843). This trial currently has 10 active sites and is being conducted in partnership with Kite Pharmaceuticals, Inc., a Gilead company (“Kite”), which markets Yescarta. The Company is also in the final planning stages for a Phase 2/3 trial for lenzilumab to treat patients who have undergone allogeneic hematopoietic stem cell therapy (“HSCT”) who are at high and intermediate risk for acute GvHD. The trial is expected to be conducted by the IMPACT Partnership, a collection of 22 stem cell transplant centers located in the United Kingdom. The Company’s proprietary, patented Humaneered technology platform is a method for converting existing antibodies (typically murine) into engineered, high-affinity human antibodies designed for therapeutic use, particularly with acute and chronic conditions. The Company has developed or in-licensed targets or research antibodies, typically from academic institutions, and then applied our Humaneered technology to produce them. Lenzilumab and the Company’s other two product candidates, ifabotuzumab and HGEN005, are Humaneered monoclonal antibodies. The Company’s Humaneered antibodies are closer to human antibodies than chimeric or conventionally humanized antibodies and have a high affinity for their target but low immunogenicity. The Company believes its Humaneered antibodies offer additional advantages, such as high potency, a slow off-rate and a lower likelihood to induce an inappropriate immune response or infusion related reactions. Our Pipeline The Company’s lenzilumab-based clinical-stage pipeline comprises a Phase 3 potential registration study in COVID-19 which has fully enrolled, the NIH-sponsored and funded ACTIV-5/BET program in COVID-19, a currently enrolling Phase 1b/2 study (ZUMA-19) as sequenced therapy of lenzilumab and Yescarta, a planned Phase 2/3 study in acute GvHD, and a planned Phase 2 study in CMML, the latter two of which the Company expects will be majority funded by partners. While the majority of the Company’s clinical programs involve lenzilumab, it has also fully enrolled an ifabotuzumab Phase 1 study in GBM. Except for the potential of lenzilumab for COVID-19 under an EUA, the Company’s product candidates are in the clinical stage of development and will require substantial time, resources, research and development, and regulatory approval prior to commercialization. Furthermore, it may be years before any of its products are approved for use, if at all. The Company’s current pipeline is depicted below: 1 2 3 Liquidity and Going Concern The Consolidated Financial Statements for the years ended December 31, 2020 and 2019 were prepared on the basis of a going concern, which contemplates that the Company will be able to realize assets and discharge liabilities in the normal course of business. However, the Company has incurred net losses since its inception and has negative operating cash flows. These conditions raised substantial doubt about the Company’s ability to continue as a going concern as described in the Company’s historical Condensed Consolidated Financial Statements included in its Annual Report on Form 10-K for the fiscal year ended December 31, 2019 and in its Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020 and June 30, 2020. The Company has been continuing to advance its efforts to submit an application for EUA for lenzilumab, with potential product launch subject to EUA being granted as early as the second quarter of 2021, in the event data from the Phase 3 clinical trial are favorable. The Company currently anticipates that top-line data from the trial will be available in the first quarter of 2021. To support the potential launch of lenzilumab under an EUA, the Company has entered into agreements with several organizations for clinical trial services, contract manufacturing services and commercialization services, as more fully described under “Item 1. Business—Manufacturing and Raw Materials.” The agreements currently in effect commit the Company to spend approximately $58 million during the first quarter of 2021 in support of these efforts. The Company expects to be able to fund these cash commitments from its cash and cash equivalents on hand, which approximated $67.7 million as of December 31, 2020, although it may pursue other funding opportunities on an opportunistic basis to support our liquidity. The Company is working with its existing contract manufacturing organizations and with additional contract manufacturing organizations to bolster its ability to supply lenzilumab in the event of receipt of EUA. Most of these manufacturing agreements, like the ones currently in place, are expected to require payment of upfront fees upon execution and further payments against performance of the manufacturing services to be provided, often over a lengthy performance period. Given the competitive environment, it is not possible for the Company to estimate the aggregate amount of these potential future payments or the timing in which they may be made. If the COVID-19 clinical study is successful and an EUA is granted in the second quarter of 2021, the Company expects to be able to satisfy the bulk of the cash requirements associated with its manufacturing commitments from revenues from the commercial sale of lenzilumab, supplemented as necessary with proceeds from the sale of its equity securities; the incurrence of debt; upfront and milestone payments from licensees; and government funding or financial support, if offered. Following completion of the 2020 Private Placement in June 2020 and the 2020 Underwritten Public Offering in September 2020, as well as net proceeds received from sales of its common stock under the Controlled Equity Offering Sales Agreement of $36.2 million (unaudited), as of March 5, 2021, the Company had cash and cash equivalents of $74.3 million (unaudited). Accordingly, the Company re-evaluated its potential going concern disclosure requirements in accordance with ASC 205-40-50 as of the date of filing. Upon completion of this evaluation, the Company has concluded that its existing cash and cash equivalents have alleviated that prior substantial doubt about the Company’s ability to continue as a going concern. The Company believes that its cash and cash equivalents will be sufficient to fund its planned operations and capital expenditure requirements for at least 12 months. This evaluation is based on relevant conditions and events that are currently known or reasonably knowable. As a result, the Company could deplete its available capital resources sooner than it currently expects, and a delay in obtaining or failure to obtain an EUA could further constrain its cash resources. The Company has based these estimates on assumptions that may prove to be wrong, and its operating projections, including its projected net revenue following the potential receipt of an EUA for lenzilumab in COVID-19 patients, may change as a result of many factors currently unknown to it. If the Company is unable to raise additional capital when needed or on acceptable terms, it would be forced to delay, reduce, or eliminate its research and development programs and commercialization efforts. Alternatively, the Company might raise funds through strategic collaborations, public or private financings or other arrangements. Such funding, if needed, may not be available on favorable terms, or at all. The financial statements included herein do not include any adjustments that might result from the outcome of these uncertainties.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include all adjustments necessary for the presentation of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. The Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiaries. These financial statements have been prepared on a basis that assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the Consolidated Financial Statements and accompanying notes. Actual results could differ materially from those estimates. The Company believes judgment is involved in accounting for the fair value-based measurement of stock-based compensation, accruals, convertible notes and warrants. The Company evaluates its estimates and assumptions as facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from these estimates and assumptions, and those differences could be material to the Consolidated Financial Statements. Concentration of Credit Risk Cash, cash equivalents, and marketable securities consist of financial instruments that potentially subject the Company to a concentration of credit risk in the event of a default by the related financial institution holding the securities, to the extent of the value recorded in the balance sheet. The Company invests cash that is not required for immediate operating needs primarily in highly liquid instruments with lower credit risk. The Company has established guidelines relating to the quality, diversification, and maturities of securities to enable the Company to manage its credit risk. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking, interest-bearing and demand money market accounts. Restricted Cash Restricted cash at December 31, 2020 and 2019 of $70 thousand and $71 thousand, respectively, relates to a standby letter of credit in the amount of approximately $50 thousand issued in connection with certain insurance policy coverage maintained by the Company and restricted cash related to a credit card facility in the amount of approximately $20 thousand. Debt Issue Costs Debt issuance costs related to a recognized debt liability are presented on the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and are amortized to interest expense over the term of the related debt using the effective interest method. Research and Development Expenses Development costs incurred in the research and development of new product candidates are expensed as incurred, including expenses that may or may not be reimbursed under research and development collaboration arrangements. Research and development costs include, but are not limited to, salaries, benefits, stock-based compensation, laboratory supplies, allocated overhead, fees for professional service providers and costs associated with product development efforts, including preclinical studies and clinical trials. The Company estimates preclinical study and clinical trial expenses based on the services performed, pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on its behalf. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Payments made to third parties under these arrangements in advance of the receipt of the related services are recorded as prepaid expenses until the services are rendered. The Company records upfront and milestone payments made to third parties under licensing arrangements as an expense. Upfront payments are recorded when incurred and milestone payments are recorded when the specific milestone has been achieved. Revenue Recognition The Company’s revenue to date has been generated primarily through license agreements and research and development collaboration agreements. The Company recorded $0.3 million for the year ending December 31, 2020 related to a licensing agreement dated November 3, 2020 (See Note 3 – License Revenue) and had no revenues for the year ending December 31, 2019. Commencing January 1, 2018, the Company recognizes revenue in accordance with FASB Accounting Standards Codification (“ASC”) Topic 606 – Revenue from Contracts with Customers Revenue under technology licenses and collaborative agreements typically consists of nonrefundable and/or guaranteed license fees, collaborative research funding, and various milestone and future product royalty or profit-sharing payments. The fair value of deliverables under the arrangement may be derived using a best estimate of selling price if vendor specific objective evidence and third-party evidence is not available. Deliverables under the arrangement will be separate units of accounting if a delivered item has value to the customer on a standalone basis and if the arrangement includes a general right of return for the delivered item, delivery or performance of the undelivered item is considered probable and substantially in the Company’s control. The Company recognizes upfront license payments as revenue upon delivery of the license only if the license has standalone value from any undelivered performance obligations and that value can be determined. The undelivered performance obligations typically include manufacturing or development services or research and/or steering committee services. If the fair value of the undelivered performance obligations can be determined, then these obligations would be accounted for separately. If the license is not considered to have standalone value, then the license and other undelivered performance obligations would be accounted for as a single unit of accounting. In this case, the license payments and payments for performance obligations are recognized as revenue over the estimated period of when the performance obligations are performed or deferred indefinitely until the undelivered performance obligation is determined. Whenever the Company determines that an arrangement should be accounted for as a single unit of accounting, the Company determines the period over which the performance obligations will be performed, and revenue will be recognized. Revenue is recognized using a proportional performance or straight-line method. The proportional performance method is used when the level of effort required to complete performance obligations under an arrangement can be reasonably estimated. The amount of revenue recognized under the proportional performance method is determined by multiplying the total payments under the contract, excluding royalties and payments contingent upon achievement of milestones, by the ratio of the level of effort performed to date to the estimated total level of effort required to complete performance obligations under the arrangement. If the Company cannot reasonably estimate the level of effort to complete performance obligations under an arrangement, the Company recognizes revenue under the arrangement on a straight-line basis over the period the Company is expected to complete its performance obligations. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which the Company is expected to complete its performance obligations under an arrangement. The Company’s collaboration agreements typically entitle the Company to additional payments upon the achievement of development, regulatory and sales performance-based milestones. If the achievement of a milestone is considered probable at the inception of the collaboration, the related milestone payment is included with other collaboration consideration, such as upfront fees and research funding, in the Company’s revenue calculation. Typically, these milestones are not considered probable at the inception of the collaboration. As such, milestones will typically be recognized in one of two ways depending on the timing of when the milestone is achieved. If the milestone is achieved during the performance period, then the Company will only recognize revenue to the extent of the proportional performance achieved at that date, or the proportion of the straight-line basis achieved at that date, and the remainder will be recorded as deferred revenue to be amortized over the remaining performance period. If the milestone is achieved after the performance period has completed and all performance obligations have been delivered, then the Company will recognize the milestone payment as revenue in its entirety in the period the milestone was achieved. See Note 3 for information on the 2020 Korea License Agreement. Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. The FASB subsequently issued ASU No. 2018-10 and 2018-11 in July 2018, which provide clarifications and improvements to ASU 2016-02 (collectively, the “new lease standard”). ASU No. 2018-11 provides the optional transition method which allows companies to apply the new lease standard at the adoption date instead of at the earliest comparative period presented and continue to apply the provisions of the previous lease standard in its annual disclosures for the comparative periods. The new lease standard requires lessees to present a right-of-use asset and a corresponding lease liability on the balance sheet. Additional footnote disclosures related to leases are also required. On January 1, 2019, the Company adopted the new lease standard using the optional transition method and certain other practical expedients. Under the practical expedient package elected, the Company is not required to reassess whether expired or existing contracts are or contain a lease; and is not required to reassess the lease classifications or reassess the initial direct costs associated with expired or existing leases. The new lease standard also provides practical expedients for an entity’s ongoing accounting. The Company elected the short-term lease recognition exemption for all leases that qualify. This means, for those leases that qualify, we will not recognize right of use assets or lease liabilities, and this includes not recognizing right of use assets or lease liabilities for existing short-term leases of those assets in transition. The Company elected the practical expedient to not separate lease and non-lease components for certain classes of assets. During 2019 and a portion of 2020, the Company sub-leased office space under a short-term lease in Burlingame, California. On September 1, 2020 we entered into a one-year lease for a small office in the same building in Burlingame, California for $1,200 per month. Management has determined the lease term to be less than 12 months, including renewals, and therefore has not recorded a right-of-use asset and corresponding liability under the short-term lease recognition exemption. Lease costs for the years ended December 31, 2020 and 2019 totaled approximately $6,100 and $10,700, respectively and are included in the Consolidated Statements of Operations. Because the Company has elected to adopt the transitional practical expedients, Management was not required to reassess whether any existing or expired contracts contained embedded leases. The Company has not entered into any contracts during the 2020 fiscal year that contain an embedded lease. Stock-Based Compensation Expense The Company measures stock-based compensation expense for stock awards at the grant date, based on the fair value-based measurement of the award, and the expense is recorded over the related service period, generally the vesting period, net of estimated forfeitures. The Company calculates the fair value-based measurement of stock options using the Black-Scholes valuation model and the single-option method and recognizes expense using the straight-line attribution approach. Income Taxes The Company accounts for income taxes under an asset-and-liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for tax and financial reporting purposes measured by applying enacted tax rates and laws that will be in effect when the differences are expected to reverse, net operating loss carryforwards and tax credits. Valuation allowances are provided when necessary to reduce net deferred tax assets to an amount that is more likely than not to be realized. The Company’s policy is to include interest and penalties related to unrecognized tax benefits within the Company’s provision for income taxes. Net Loss Per Common Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, stock options, restricted stock units and common stock warrants are considered to be potentially dilutive securities but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented. The Company’s potential dilutive securities, which include stock options, restricted stock units and warrants have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per common share and be antidilutive. Therefore, the denominator used to calculate both basic and diluted net loss per common share is the same in all periods presented. The following shares subject to outstanding potentially dilutive securities have been excluded from the computations of diluted net loss per common share as the effect of including such securities would be antidilutive: Year Ended December 31, 2020 2019 Options to purchase common stock 3,728,149 3,176,336 Warrants to purchase common stock 51,238 66,238 3,779,387 3,242,574 Segment Reporting The Company determines its segment reporting based upon the way the business is organized for making operating decisions and assessing performance. The Company operates in only one segment, which is related to the development of pharmaceutical products.

License Revenue

License Revenue	12 Months Ended
	Dec. 31, 2020
License Revenue
License Revenue	3. License Revenue On November 3, 2020, the Company entered into a License Agreement (the “South Korea Agreement”) with KPM Tech Co., Ltd. (“KPM”) and its affiliate, Telcon RF Pharmaceutical, Inc. (together with KPM, the “Licensee”). Pursuant to the South Korea Agreement, among other things, the Company granted the Licensee a license under certain patents and other intellectual property to develop and commercialize the Company’s lead product candidate, lenzilumab (the “Product”), for treatment of COVID-19 pneumonia, in South Korea and the Philippines (the “Territory”), subject to certain reservations and limitations. The Licensee will be responsible for gaining regulatory approval for, and subsequent commercialization of, lenzilumab in the Territory. As consideration for the license, the Licensee has agreed to pay the Company (i) an up-front license fee of $6.0 million, payable promptly following the execution of the License Agreement, (ii) up to an aggregate of $14.0 million in two payments based on achievement by the Company of two specified milestones in the US, and (iii) subsequent to the receipt by the Licensee of the requisite regulatory approvals, double-digit royalties on the net sales of lenzilumab in South Korea and the Philippines. The Licensee has agreed to certain development and commercial performance obligations. It is expected that the Company will supply lenzilumab to the Licensee for a minimum of 7.5 years at a cost-plus basis from an existing or future manufacturer. The Licensee has agreed to certain minimum purchases of lenzilumab on an annual basis. The Company assessed the South Korea Agreement in accordance with ASC 606 and ASC 808 – Collaborative Arrangements The Company has concluded that the nature of its promise is to stand ready to provide Research and Development Services as needed during the Performance Period (as defined below). The Company has further concluded that for all of the increments of time during the Performance Period its promise of standing ready to provide the Services is substantially the same. While the specific tasks performed during each increment of time will vary, the nature of the overall promise to provide the Services remains the same throughout the Performance Period. Since the provision of the license and the Services are considered a single performance obligation, the $4.5 million upfront payment ($6.0 million net of withholding taxes and other fees and royalties) is being recognized as revenue ratably over the 29-month period through March of 2023 (the “Performance Period”), the expected period over which the Company conservatively expects the Services to be performed with approval in the Territory expected by the end of March 2023. Therefore, in November and December 2020, the Company has recognized license revenue totaling approximately $0.3 million. Licensee’s purchases of lezilumab for development purposes or for commercial requirements, represent options under the agreement and revenues will therefore be recognized when control of the product is transferred to Licensee.

Savant Arrangements

Savant Arrangements	12 Months Ended
	Dec. 31, 2020
Savant Arrangements
Savant Arrangements	4. Savant Arrangements On February 29, 2016, the Company entered into a binding letter of intent (the “LOI”) with Savant Neglected Diseases, LLC (“Savant”). The LOI provided that the Company would acquire certain worldwide rights relating to benznidazole from Savant. On June 30, 2016, the Company and Savant entered into an Agreement for the Manufacture, Development and Commercialization of Benznidazole for Human Use (the “MDC Agreement”), pursuant to which the Company acquired certain worldwide rights relating to benznidazole. The MDC Agreement consummates the transactions contemplated by the LOI. In addition, on June 30, 2016, the Company and Savant also entered into a Security Agreement (the “Security Agreement”), pursuant to which the Company granted Savant a continuing senior security interest in the assets and rights acquired by the Company pursuant to the MDC Agreement and certain future assets developed from those acquired assets. On June 30, 2016, in connection with the MDC Agreement, the Company issued to Savant a five-year warrant to purchase 200,000 shares of the Company’s Common Stock, at an exercise price of $2.25 per share, subject to adjustment. See Note 7. On May 26, 2017, the Company submitted its benznidazole Investigational New Drug Application (“IND”) to the Food and Drug Administration (“FDA”) which became effective on June 26, 2017. The Company recorded expense of $1.0 million during the year ended December 31, 2017 as Research and development expense related to the milestone achievement associated with the IND being declared effective. On July 10, 2017, FDA notified the Company that it granted Orphan Drug Designation to benznidazole for the treatment of Chagas disease. The Company recorded expense of $1.0 million during the year ended December 31, 2017 as Research and development expense related to the milestone achievement associated with Orphan Drug Designation. The $2.0 million in milestone payments due Savant are included in Accrued expenses in the accompanying Consolidated Balance Sheets as of December 31, 2020 and 2019. In July 2017, the Company commenced litigation against Savant alleging that Savant breached the MDC Agreement and is seeking a declaratory judgement. Savant has asserted counterclaims for breaches of contract under the MDC Agreement and the Security Agreement. See Note 12 below for more information regarding the Savant litigation.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Disclosure Text Block [Abstract]
Debt	5. Debt Notes Payable to Vendors On June 30, 2016, the Company issued promissory notes in an aggregate principal amount of approximately $1.2 million to certain claimants in accordance with the Company’s Plan of Reorganization (the “Plan”) filed with the United States Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”) (Case No. 15-12628 (LSS) (the “Bankruptcy Case”) which became effective June 30, 2016, at which time the Company emerged from its Chapter 11 bankruptcy proceedings. The notes were unsecured, accrued interest at 10% per annum and became due and payable in full, including principal and accrued interest on June 30, 2019. In July and August, 2019, following the receipt of proceeds from the 2019 Bridge Notes, the Company used approximately $0.5 million of the proceeds to retire a portion of these notes, including accrued interest. After giving effect to these payments, the aggregate principal amount and accrued but unpaid interest on these notes approximated $1.1 million as of December 31, 2019 and the Company had accrued $0.3 million in interest expense. In June and July 2020, the Company used the proceeds from the Private Placement (as defined below) to repay the remaining outstanding principal including accrued and unpaid interest on these notes and the notes were extinguished. As of December 31, 2020, all the notes have been repaid. Advance Notes In June, July and August, 2018 the Company received an aggregate of $0.9 million of proceeds from advances made to the Company (the “Advance Notes”) by four different lenders including Dr. Cameron Durrant, the Company’s Chairman and Chief Executive Officer; Cheval Holdings, Ltd. (“Cheval”), an affiliate of Black Horse Capital, L.P. (“BHC”), the Company’s controlling stockholder at the time; and Ronald Barliant, a director of the Company. The Advance Notes accrued interest at a rate of 7% per year, compounded annually. In accordance with their terms, on May 30, 2019, in connection with the Company’s announcement of the Collaboration Agreement with Kite, the lenders converted the amounts due under the Advance Notes into the Company’s common stock at the conversion price of $2.25 per share. The Company issued a total of 435,924 shares of common stock in connection with the conversion. Convertible Notes 2018 Convertible Notes Commencing September 19, 2018, the Company delivered a series of convertible promissory notes (the “2018 Notes”) evidencing an aggregate of $2.5 million of loans made to the Company by six different lenders, including an affiliate of BHC, the Company’s controlling stockholder at the time. The 2018 Notes accrued interest at a rate of 7% per annum and, in general, were set to mature twenty-four months from the date the 2018 Notes were signed. The Company used the proceeds from the 2018 Notes for working capital. The 2018 Notes were convertible into equity securities of the Company in three different scenarios, including if the Company sold its equity securities on or before the date of repayment of the 2018 Notes in any financing transaction that resulted in gross proceeds to the Company of less than $10 million (a “Non-Qualified Financing”). In connection with a Non-Qualified Financing, the noteholders were able to convert their remaining 2018 Notes into either (i) such equity securities as the noteholder would acquire if the principal and accrued but unpaid interest thereon (the “Conversion Amount”) were invested directly in the financing on the same terms and conditions as given to the financing investors in the Non-Qualified Financing, or (ii) common stock at a conversion price equal to $2.25 per share (subject to ratable adjustment for any stock split, stock dividend, stock combination or other recapitalization occurring subsequent to the date of the Notes). The Company’s sales of shares pursuant to the ELOC Purchase Agreement with Lincoln Park constituted a Non-Qualified Financing. Commencing on April 2, 2020, the holders of the 2018 Notes notified the Company of their exercise of their conversion rights under the 2018 Notes. See “2019 Convertible Notes” for additional information regarding the conversion of 2018 Notes by the holders. As of December 31, 2019, the Company had accrued $0.2 million in interest related to these promissory notes. Interest expense recorded during the year ended December 31, 2020 was approximately $817 thousand. 2019 Convertible Notes Commencing on April 23, 2019, the Company delivered a series of convertible promissory notes (the “2019 Notes” and together with the 2018 Notes, the “Convertible Notes”) evidencing an aggregate of $1.3 million of loans made to the Company. The 2019 Notes accrued interest at a rate of 7.5% per annum and, in general, were set to mature twenty-four months from the date the 2019 Notes were signed. The Company used the proceeds from the 2019 Notes for working capital. The 2019 Notes were convertible into equity securities of the Company in four different scenarios, including if the Company sold its equity securities on or before the date of repayment of the 2019 Notes in any financing transaction that resulted in gross proceeds to the Company of less than $10 million (a “Non-Qualified Financing”). In connection with a Non-Qualified Financing, the noteholders were able to convert their remaining 2019 Notes into either (i) such equity securities as the noteholder would acquire if the Conversion Amount were invested directly in the financing on the same terms and conditions as given to the financing investors in the Non-Qualified Financing, or (ii) common stock at a conversion price equal to $6.25 per share (subject to ratable adjustment for any stock split, stock dividend, stock combination or other recapitalization occurring subsequent to the date of the 2019 Notes). The Company’s sales of shares pursuant to the ELOC Purchase Agreement with LPC constituted a Non-Qualified Financing. Commencing on April 2, 2020, holders of the Convertible Notes, including Cheval, an affiliate of BHC, the Company’s controlling stockholder at the time, notified the Company of their exercise of their conversion rights under the Convertible Notes. Pursuant to the exemption from registration afforded by Section 3(a)(9) under the Securities Act, the Company issued an aggregate of 2,397,915 shares of its common stock upon the conversion of $4.3 million in aggregate principal and interest on the Convertible Notes that were converted, which obligations were retired. Of these, the Company issued 316,666 shares to Cheval. Dr. Dale Chappell, who was serving as the Company’s ex-officio chief scientific officer at the time and currently serves as its Chief Scientific Officer, controls BHC and reports beneficial ownership of all shares held by it and its affiliates, including Cheval. After giving effect to the shares issued upon such conversions, no convertible notes issued in 2018 or 2019 were outstanding as of December 31, 2020. As of December 31, 2019, the Company had accrued $0.1 million in interest related to the 2019 Notes. Interest expense related to the 2019 Notes, recorded during the year ended December 31, 2020, was approximately $219 thousand. The Advance Notes, the 2018 Notes and the 2019 Notes had an optional voluntary conversion feature in which the holder could convert the notes in the Company’s common stock at maturity at a conversion rate of $2.25 per share for the Advance Notes and the 2018 Notes and at a conversion rate of $6.25 for the 2019 Notes. The intrinsic value of this beneficial conversion feature was $1.8 million upon the issuance of the Advance Notes, the 2018 Notes and the 2019 Notes and was recorded as additional paid-in capital and as a debt discount which was accreted to interest expense over the term of the Advance Notes and Notes. Interest expense includes debt discount amortization of $785 thousand for the year ended December 31, 2020. The Company evaluated the embedded features within the Advance Notes, the 2018 Notes and the 2019 Notes to determine if the embedded features are required to be bifurcated and recognized as derivative instruments. The Company determined that the Advance Notes, the 2018 Notes and the 2019 Notes contain contingent beneficial conversion features (“CBCF”) that allow or require the holder to convert the Advance Notes, the 2018 Notes and the 2019 Notes, as applicable, to Company common stock at a conversion rate of $2.25 per share for the Advance Notes and the 2018 Notes and $6.25 for the 2019 Notes, but did not contain embedded features requiring bifurcation and recognition as derivative instruments. Upon the occurrence of a CBCF that results in conversion of the Advance Notes, the 2018 Notes or the 2019 Notes to Company common stock, the remaining unamortized discount will be charged to interest expense. Upon conversion of the Advance Notes on May 30, 2019, the remaining unamortized discount was charged to interest expense. Upon the conversion of the Convertible Notes in April 2020, the remaining related unamortized discount was charged to interest expense. 2020 Convertible Redeemable Notes On March 13, 2020 and March 19, 2020 (the “Issuance Dates”), the Company delivered two convertible redeemable promissory notes (the “2020 Notes”) evidencing loans with an aggregate principal amount of $518,333 made to the Company. The 2020 Notes accrued interest at a rate of 7.0% per annum and were set to mature on March 13, 2021 and March 19, 2021, respectively. The 2020 Notes contained an original issue discount of $33,000 and $18,833, respectively. The Company used the proceeds from the 2020 Notes for working capital. The notes could be redeemed by the Company at any time before the 270 th The Company evaluated the embedded features within the 2020 Notes and determined that the embedded features are required to be bifurcated and recognized as stand-alone derivative instruments. The variable-share settlement features within the 2020 Notes qualify as redemption features and meet the net settlement criterion for qualification as a stand-alone derivative. In determining the fair value of the bifurcated derivative, the Company evaluated the likelihood of conversion of the 2020 Notes to Company stock. As the Company believed it would have adequate funding prior to the six-month anniversary of the 2020 Notes, the first conversion option for the holders of the 2020 Notes, and it had the intent to either begin making amortizing payments or to pay off the 2020 Notes in their entirety prior to that date, the fair value was determined to be $0. The original issue discount was accreted to interest expense and the remaining balance was charged to interest expense upon payoff. Interest expense related to the 2020 Notes, recorded during the year ended December 31, 2020, was approximately $165 thousand. Interest expense includes the original issue discount amortization of approximately $52 thousand for the year ended December 31, 2020. Bridge Notes On June 28, 2019, the Company issued three short-term, secured bridge notes (the “June Bridge Notes”) evidencing an aggregate of $1.7 million of loans made to the Company by three parties: Cheval, an affiliate of BHC, the Company’s controlling stockholder at the time, lent $750,000; Nomis Bay LTD, the Company’s second largest stockholder, lent $750,000; and Dr. Cameron Durrant, the Company’s Chief Executive Officer and Chairman of the Board of Directors (the “Board”), lent $200,000. The proceeds from the June Bridge Notes were used to satisfy a portion of the unsecured obligations incurred in connection with the Company’s emergence from bankruptcy in 2016 and for working capital and general corporate purposes. Of the $1.7 million in proceeds received, $950,000 was received on June 28, 2019 and was recorded as Advance notes in the Condensed Consolidated Balance Sheet as of June 30, 2019. The remaining proceeds of $750,000 were received July 1, 2019 and recorded accordingly. The June Bridge Notes accrued interest at a rate of 7.0% per annum and after giving effect to multiple extensions, were set to mature on December 31, 2020. The June Bridge Notes could become due and payable at such earlier time as the Company raised more than $3,000,000 in a bona fide financing transaction or upon a change in control. Accordingly, the June Bridge Notes were repaid in June 2020 with proceeds from the Private Placement, and the June Bridge Notes were extinguished. On November 12, 2019, the Company issued two short-term, secured bridge notes (the “November Bridge Notes” and together with the June Bridge Notes, the “2019 Bridge Notes”) evidencing an aggregate of $350,000 of loans made to the Company by two parties: Cheval, an affiliate of BHC, our controlling stockholder at the time, lent $250,000; and Dr. Cameron Durrant, our Chief Executive Officer and Chairman of our Board, lent $100,000 The November Bridge Notes ranked on par with the June Bridge Notes and possessed other terms and conditions substantially consistent with those notes. The November Bridge Notes accrued interest at a rate of 7.0% per annum and after giving effect to multiple extensions, were set to mature on December 31, 2020. The November Bridge Notes could become due and payable at such earlier time as the Company raised more than $3,000,000 in a bona fide financing transaction or upon a change in control. Accordingly, the November Bridge Notes were repaid in June 2020 with proceeds from the Private Placement. In April 2020, the Company issued two short-term, secured bridge notes (the “April Bridge Notes” and together with the June Bridge Notes and the November Bridge Notes, the “Bridge Notes”) evidencing an aggregate of $350,000 of loans made to the Company: Cheval, an affiliate of BHC, the Company’s controlling stockholder at the time, loaned $100,000, and Nomis Bay, the Company’s second largest stockholder, loaned $250,000. The proceeds from the April Bridge Notes were used for working capital and general corporate purposes. The April Bridge Notes ranked on par with the June Bridge Notes and the November Bridge Notes and possessed other terms and conditions substantially consistent with them. The notes accrued interest at a rate of 7.0% per annum and were set to mature on December 31, 2020. The April Bridge Notes could become due and payable at such earlier time as the Company raised more than $10,000,000 in a bona fide financing transaction or upon a change in control. Accordingly, these April Bridge Notes were repaid in June 2020 with proceeds from the Private Placement, and these bridge notes were extinguished. The Bridge Notes were secured by a lien on substantially all the Company’s assets, which liens have been released. Interest expense related to the Bridge Notes, recorded during the year ended December 31, 2020, was approximately $66 thousand.

Warrants to Purchase Common Sto

Warrants to Purchase Common Stock	12 Months Ended
	Dec. 31, 2020
Warrants to Purchase Common Stock
Warrants to Purchase Common Stock	6. Warrants to Purchase Common Stock On June 19, 2013, the Company issued a warrant to purchase up to an aggregate of 1,238 shares of common stock at an exercise price of $484.80 per share. The warrant expires on the tenth anniversary of its issuance date. As of December 31, 2020, these warrants were fully vested. On December 4, 2015, the Company issued a warrant to purchase up to an aggregate of 25,000 shares of common stock at an exercise price of $146.60 per share. The warrant expired on December 4, 2020. On June 30, 2016, in connection with the MDC Agreement described in Note 5, the Company issued to Savant a five-year warrant (the “Savant Warrant”) to purchase 40,000 shares of the Company’s Common Stock, at an exercise price of $11.25 per share, subject to adjustment. The Savant Warrant was exercisable for 25% of the shares immediately and exercisable for the remaining shares upon reaching certain regulatory related milestones. In addition, pursuant to the MDC Agreement, the Company had granted Savant certain “piggyback” registration rights for the shares issuable under the Savant Warrant. The Company determined the initial fair value of the Savant Warrant to be approximately $0.7 million as of June 30, 2016. The Company reevaluated the performance conditions and expected vesting of the Warrant quarterly during 2017 and 2018 and recorded a reduction of expense of approximately $0.1 million during the year ended December 31, 2017. The expense reduction was due to a decline in the fair value, which reduction was included in Research and development expenses. Specifically, as a result of the FDA granting accelerated and conditional approval of a benznidazole therapy manufactured by the Chemo Group (“Chemo”) for the treatment of Chagas disease and awarding Chemo a neglected tropical disease PRV, the Company re-evaluated the final two vesting milestones and concluded that the probability of achievement of these milestones had decreased to 0%. As of December 31, 2019, 20,000 of these warrants were fully vested and 20,000 were not vested. On June 30, 2020, Savant exercised 20,000 warrants in a cashless exercise resulting in 10,909 shares being issued to Savant in July 2020. The remaining unvested warrant for an aggregate of up to 20,000 shares will expire on June 30, 2021. The Company will continue to reevaluate the performance conditions and expected vesting of the Savant Warrant on a quarterly basis until all performance conditions have been met or the warrants expire. On April 22, 2020, in connection with investor relation services, the Company issued two warrants to purchase up to an aggregate of 8,000 shares of common stock at an exercise price of $0.05 per share. The warrants were to vest upon either a change of control, as defined in the warrant agreement, an uplisting to a national securities exchange, or eight years from the issuance date and were to expire two years after full vesting. On September 18, 2020, the Company’s common stock commenced trading on the Nasdaq Capital Market and on the same day the warrants became vested and were exercised for proceeds of $400. On May 20, 2020, in connection with investor relation services, the Company issued a warrant to purchase up to an aggregate of 4,000 shares of common stock at an exercise price of $0.05 per share. The warrants were to vest upon either a change of control, as defined in the warrant agreement, an uplisting to a national securities exchange, or eight years from the issuance date and were to expire two years after full vesting. On September 18, 2020, the Company’s common stock commenced trading on the Nasdaq Capital Market and on the same day the warrants became vested and were exercised for proceeds of $200. On May 20, 2020, in connection with manufacturing consulting services, the Company issued a warrant to purchase up to an aggregate of 30,000 shares of common stock at an exercise price of $4.30 per share. The warrants were fully vested on the date of issue and expire ten years from the issuance date. On September 14, 2020, in connection with investor relation services, the Company issued three warrants to purchase up to an aggregate of 200,000 shares of common stock at an exercise price of $0.05 per share. The warrants were to vest upon either a change of control, as defined in the warrant agreement, an uplisting to a national securities exchange, or eight years from the issuance date and were to expire two years after full vesting. On September 18, 2020, the Company’s common stock commenced trading on the Nasdaq Capital Market and on the same day the warrants became vested and were exercised for proceeds of $10,000.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Operating Leases The Company leased office space in Brisbane, California, which lease was month-to-month and commenced in April 2018. The Company terminated the lease on November 19, 2019 and entered into a sub-lease agreement for office space in Burlingame, California. The sub-lease initial term expired on March 31, 2020 and was renewed until September 1, 2020 at which point the Company entered into a new lease agreement in the same building which lease will expire on August 31, 2021. As of December 31, 2020, the Company had future minimum lease payments of approximately $10 thousand. Rent expense was approximately $3 thousand and $10 thousand for the years ended December 31, 2020 and December 31, 2019, respectively. Indemnification The Company has certain agreements with service providers with which it does business that contain indemnification provisions pursuant to which the Company typically agrees to indemnify the party against certain types of third-party claims. The Company accrues for known indemnification issues when a loss is probable and can be reasonably estimated. The Company would also accrue for estimated incurred but unidentified indemnification issues based on historical activity. As the Company has not incurred any indemnification losses to date, there were no accruals for or expenses related to indemnification issues for any period presented.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Reverse Stock Split Effective as of 4:30 p.m. Eastern Time on September 11, 2020 (the “Effective Time”), the Company amended its charter to effect a reverse stock split at a ratio of 1-for-5 (the “Split Ratio”). No fractional shares were issued in connection with the reverse stock split. Stockholders of record otherwise entitled to receive fractional shares of common stock received cash (without interest or deduction) in lieu of such fractional share interests. The reverse stock split reduced the total number of shares of the Company’s common stock outstanding as of the Effective Time from approximately 210.9 million shares to approximately 42.2 million shares. The par value per share and other terms of the Company’s common stock were not affected by the reverse stock split, and the number of authorized shares of the Company’s common stock remains at 225,000,000. The reverse stock split resulted in a proportionate adjustment in the number of shares reserved for issuance under the 2020 Equity Plan, such that a total of 7,000,000 shares of the Company’s common stock were reserved for issuance under the 2020 Equity Plan following the Effective Time. In addition, proportionate adjustments were made to the number of shares covered by, and the exercise price applicable to, each outstanding stock option award under the 2012 Equity Plan and outstanding warrants issued by the Company, in each case to give effect to the Split Ratio and the reverse stock split. The reverse stock split was accounted for retroactively and is reflected in the Company’s common stock, stock option and warrant activity as of and during the years ended December 31, 2020 and 2019. Unless stated otherwise, all share data in this Annual Report on Form 10-K have been adjusted, as appropriate, to reflect the reverse stock split. Lincoln Park Capital Purchase Agreement On November 8, 2019, the Company entered into a purchase agreement (the “ELOC Purchase Agreement”) and a registration rights agreement with LPC, pursuant to which the Company had the right to sell to LPC up to $20,000,000 in shares of the Company’s common stock, $0.001 par value per share (the “Common Stock”), subject to certain limitations and conditions set forth in the ELOC Purchase Agreement. In connection with the signing of the ELOC Purchase Agreement on November 8, 2019, the Company issued 141,318 shares of its common stock to LPC. The issuance of the shares was recorded as debt issuance costs in Common stock and Additional paid-in capital with no net effect on Stockholders’ equity (deficit). During the months of December 2019 and January 2020, the Company issued a total of 140,000 shares for aggregate proceeds of $0.3 million under the ELOC Purchase Agreement. On June 2, 2020, following completion of the Private Placement described below, the Company notified LPC of its decision to terminate the ELOC Purchase Agreement. The termination of the ELOC Purchase Agreement became effective on June 3, 2020. 2020 Private Placement On June 1, 2020, the Company entered into a securities purchase agreement (the “Purchase Agreement”) with certain accredited investors (the “Investors”) to complete a private placement of our common stock (the “Private Placement”). The closing of the Private Placement occurred on June 2, 2020 (the “Closing Date”). At the closing, the Company issued and sold 16,505,743 shares of its common stock (the “Shares”) at a purchase price of $4.35 per share, for aggregate gross proceeds of approximately $71.8 million. The Company used a portion of the proceeds to retire certain indebtedness, as further described in Note 6 - Debt. See Note 12 for information regarding two complaints filed against us in connection with the Private Placement. On the Closing Date, the Company and the Investors also entered into a registration rights agreement (the “Registration Rights Agreement”) pursuant to which the Company agreed to prepare and file a registration statement (the “Resale Registration Statement”) for the resale of the Shares with the Securities and Exchange Commission. Subject to certain limitations and an overall cap, the Company may be required to pay liquidated damages to the investors at a rate of 2% of the invested capital for each occurrence (and continuation for 30 consecutive days thereafter) of a breach by the Company of certain of its obligations under the Registration Rights Agreement. The Purchase Agreement also required that the Company use its commercially reasonable efforts to achieve a listing of the Common Stock on a national securities exchange, subject to certain limitations set forth in the Purchase Agreement. On July 6, 2020, the Company applied to have its common stock approved for listing on the Nasdaq Capital Market. On September 18, 2020, the Company’s common stock commenced trading on the Nasdaq Capital Market under the symbol “HGEN.” 2020 Underwritten Public Offering On September 17, 2020, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with J.P. Morgan Securities LLC and Jefferies LLC, as representatives of the several underwriters, in connection with the public offering of 8,000,000 of the Company’s shares of common stock. Pursuant to the Underwriting Agreement, the Company granted the underwriters a 30-day option to purchase an additional 1,200,000 shares of common stock, which option was exercised in full by the underwriters on September 18, 2020 As a result of the pricing of the public offering, the Company’s common stock commenced trading on the Nasdaq Capital Market under the symbol “HGEN.” The aggregate gross proceeds from the sale of the full 9,200,000 shares in the offering were approximately $78.2 million. The Company expects to use the proceeds from the offering to support its manufacturing, production and commercial preparation activities relating to lenzilumab as a potential therapy for COVID-19 patients and for working capital and other general corporate purposes. The Company has reserved the following shares of common stock for issuance as of December 31, 2020: Warrants to purchase common stock 51,238 Options: Outstanding under the 2020 Equity Incentive Plan 637,286 Outstanding under the 2012 Equity Incentive Plan 3,090,821 Outstanding under the 2001 Equity Incentive Plan 42 Available for future grants under the 2020 Equity Incentive Plan 6,349,911 10,129,298 Controlled Equity Offering On December 31, 2020, the Company entered into a Controlled Equity Offering SM 2020 Equity Plan On July 27, 2020, the Board unanimously approved, and recommended that the Company’s stockholders approve, the 2020 Equity Plan, to ensure that the Board and its compensation committee (the “Compensation Committee”) will be able to make the types of awards, and covering the number of shares, as necessary to meet the Company’s compensatory needs. On July 29, 2020, the 2020 Equity Plan was approved by the holders of approximately 63% of the Company’s outstanding shares of common stock on that date. The 2020 Equity Plan became effective on September 11, 2020 following the Effective Time of the reverse stock split. Immediately following the Effective Time, a total of 7,000,000 shares of the Company’s common stock were reserved for issuance under the 2020 Equity Plan. The Board or Compensation Committee may grant the following types of awards under the 2020 Equity Plan: stock options, stock appreciation rights, restricted stock, stock awards, restricted stock units, performance shares, performance units, cash-based awards and substitute awards. The 2020 Equity Plan will remain in effect until the tenth anniversary of its effective date, unless terminated earlier by the Board. As of December 31, 2020, there were 6,349,911 shares available for grant under the 2020 Equity Incentive Plan. 2012 Equity Plan The 2020 Equity Plan replaced the 2012 Equity Plan, under which no further grants will be made. However, any outstanding awards under the 2012 Equity Plan will continue in accordance with the terms of the 2012 Equity Plan and any award agreement executed in connection with such outstanding awards. At the Effective Time of the reverse stock split, proportionate adjustments were made to the number of shares covered by, and the exercise price applicable to, each outstanding stock option award under the 2012 Equity Plan to give effect to the Split Ratio and the reverse stock split. Under the 2012 Equity Plan, the Company could grant shares, stock units, stock appreciation rights, performance cash awards and/or options to employees, directors, consultants, and other service providers. For options, the per share exercise price could not be less than the fair market value of a Company common share on the date of grant. Awards generally vest and become exercisable over three to four years and expire 10 years from the date of grant. Options generally become exercisable as they vest following the date of grant. As of December 31, 2020, there were no shares available for grant under the 2012 Equity Incentive Plan. 2001 Equity Incentive Plan Under the Company’s 2001 Stock Plan (the “2001 Plan”), the Company was able to grant shares and/or options to purchase up to 426,030 shares of common stock to employees, directors, consultants, and other service providers. In connection with the 2012 Plan taking effect, the 2001 Plan was terminated in August 2012. However, the awards under the 2001 Plan outstanding as of the termination of the 2001 Plan continued to be governed by their existing terms. Stock Option Activity The following table summarizes stock option activity for the years ended December 31, 2020 and 2019: Number of Weighted Average Price (per Weighted- Aggregate Outstanding at January 1, 2019 3,081,863 $ 4.75 Granted 294,191 3.90 Exercised (97,725 ) 3.35 Cancelled (forfeited) (101,984 ) 3.10 Cancelled (expired) (9 ) 48.40 Outstanding at December 31, 2019 3,176,336 4.75 Granted 981,164 7.35 Exercised (429,330 ) 3.55 Cancelled (expired) (21 ) 58.40 Outstanding at December 31, 2020 3,728,149 $ 5.57 7.6 $ 44,479 Options vested and expected to vest 3,715,473 $ 5.57 7.6 $ 44,328 Exercisable 2,999,502 $ 5.07 7.2 $ 10 ______________________ (1) The weighted average price per share is determined using exercise price per share for stock options. (2) The aggregate intrinsic value is calculated as the difference between the exercise price of the option and the fair value of the Company’s common stock for in-the-money options at December 31, 2020. The stock options outstanding and exercisable by exercise price at December 31, 2020 are as follows: Stock Options Outstanding Stock Options Exercisable Range of Exercise Prices Number Weighted- Weighted- Number of Weighted- $1.65 - $3.33 2,534,965 7.30 $ 3.14 2,372,837 $ 3.18 $4.20 - $9.05 343,065 8.95 $ 6.30 176,190 $ 4.92 $9.65 - $16.50 587,286 9.31 $ 10.57 187,642 $ 12.53 $16.90 - $16.90 252,604 5.62 $ 16.90 252,604 $ 16.90 $17.00 - $18.00 10,125 5.72 $ 17.01 10,125 $ 17.01 $58.40 - $86.80 42 0.09 $ 67.87 42 $ 67.87 $216.40 - $240.00 62 0.12 $ 225.92 62 $ 225.92 3,728,149 7.65 $ 5.57 2,999,502 $ 5.07 The total fair value of options vested for the years ended December 31, 2020 and 2019 was $2.2 million and $2.2 million, respectively. Stock-Based Compensation The Company’s stock-based compensation expense for stock options is estimated at the grant date based on the award’s fair value as calculated by the Black-Scholes option pricing model and is recognized as expense over the requisite service period. The Black-Scholes option pricing model requires various highly judgmental assumptions including expected volatility and expected term. The expected volatility is based on the historical stock volatilities of several of the Company’s publicly listed peers over a period equal to the expected terms of the options as the Company does not have a sufficient trading history to use the volatility of its own common stock. To estimate the expected term, the Company has opted to use the simplified method, which is the use of the midpoint of the vesting term and the contractual term. If any of the assumptions used in the Black-Scholes option pricing model changes significantly, stock-based compensation expense may differ materially in the future from that recorded in the current period. In addition, the Company is required to estimate the expected forfeiture rate and only recognize expense for those shares expected to vest. The Company estimates the forfeiture rate based on historical experience and its expectations regarding future pre-vesting termination behavior of employees. The Company reviews its estimate of the expected forfeiture rate annually, and stock-based compensation expense is adjusted accordingly. The weighted-average fair value-based measurement of stock options granted under the Company’s stock plans in the years ended December 31, 2020 and 2019 was $7.35 and $3.95 per share, respectively. The fair value- based measurement of stock options granted under the Company’s stock plans was estimated at the date of grant using the Black-Scholes model with the following assumptions: Year Ended December 31, 2020 2019 Expected term 5 - 6 years 5 - 6 years Expected volatility 95% - 111% 96% - 99% Risk-free interest rate 0.28% - 1.57% 1.74% - 2.59% Expected dividend yield 0% 0% Total expense for stock option grants recognized was as follows: Year ended December 31, 2020 2019 Selling,general and administrative $ 1,773 $ 1,928 Reseach and development 337 97 Total stock-based compensation $ 2,110 $ 2,025 At December 31, 2020, the Company had $4.1 million of total unrecognized compensation expense, net of estimated forfeitures, related to outstanding stock options that will be recognized over a weighted-average period of 2.3 years.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes No provision for federal income taxes has been recorded for the years ended December 31, 2020 and 2019 due to net losses and the valuation allowance established. Deferred tax assets and liabilities reflect the net tax effects of net operating loss and tax credit carryovers and the temporary differences between the carrying amounts of assets and liabilities for financial reporting and the amounts used for income tax purposes. Significant components of the Company's deferred tax assets are as follows: As of December 31, 2020 2019 Deferred tax assets: Net operating losses $ 75,149 $ 50,144 Research and other credits 2,178 2,178 Stock based compensation 3,256 3,001 In-Process research and development 1,193 1,253 Other 665 854 Total deferred tax assets 82,441 57,430 Valuation allowance (82,441 ) (57,430 ) Net deferred tax assets $ - $ - A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 2020 and 2019 is as follows: Year Ended December 31, 2020 2019 Statutory rate 21.0 % 21.0 % Valuation allowance (27.9 )% (26.0 )% Nondeductible stock compensation - % (0.3 )% Other 6.9 % 5.3 % Effective tax rate - % - % Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $25.0 million during 2020 and increased by $2.7 million during 2019. At December 31, 2020, the Company had federal net operating loss carryforwards of approximately $166.2 million, which expire in the years 2021 through 2037, and state net operating loss carryforwards of approximately $261.4 million, which expire in the years 2028 through 2040. The Company also has federal net operating loss carryforwards generated in 2018, 2019 and 2020 of $104.9 million that have no expiration date as a result of the December 22, 2017 Tax Cuts and Jobs Act tax reform legislation. At December 31, 2020, the Company had federal research and development credit carryforwards of approximately $1.3 million, which expire in the years 2022 through 2035 and state research and development credit carryforwards of approximately $2.2 million. The state research and development credit carryforwards can be carried forward indefinitely. During 2013, the Company completed a Section 382 study in accordance with the Internal Revenue Code of 1986, as amended, and similar state provisions. The study concluded that the Company has experienced several ownership changes since inception. This causes the Company's utilization of its net operating loss and tax credit carryforwards to be subject to substantial annual limitations. These results are reflected in the above carryforward amounts and deferred tax assets. The Company's ability to utilize its net operating loss and tax credit carryforwards are further limited as a result of subsequent ownership changes. All such limitations could result in the expiration of carryforwards before they are utilized. An ownership change may have occurred during 2015, 2016, 2017, 2018, 2019 and 2020, or all five years and in connection with the Restructuring Transactions that occurred in 2018. As a result, tax attributes such as net operating losses and research and development credits may be subject to further limitation. ASC 740 requires that the Company 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. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: Balance at December 31, 2018 $ 1,060 Additions based on tax positions related to prior year - Additions based on tax positions related to current year - Balance at December 31, 2019 1,060 Additions based on tax positions related to prior year - Additions based on tax positions related to current year - Balance at December 31, 2020 $ 1,060 There were no interest or penalties related to unrecognized tax benefits. Substantially all of the unrecognized tax benefit, if recognized to offset future taxable income would affect the Company’s tax rate. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next 12 months. Because of net operating loss carryforwards, substantially all of the Company’s tax years remain open to federal tax and state tax examination. The Company files income tax returns in the U.S. federal jurisdiction, California and Florida. Federal and California corporation income tax returns beginning with the 2001 tax year remain subject to examination by the Internal Revenue Service and the California Franchise Tax Board, respectively.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Benefit Plan	10. Employee Benefit Plan The Company has established a 401(k) tax-deferred savings plan (the “401(k) Plan”), which permits participants to make contributions by salary deduction pursuant to Section 401(k) of the Internal Revenue Code. The Company is responsible for administrative costs of the 401(k) Plan. The Company may, at its discretion, make matching contributions to the 401(k) Plan. No employer contributions have been made to the plan for the years ended December 31, 2020 and 2019.

Litigation

Litigation	12 Months Ended
	Dec. 31, 2020
Litigation [Abstract]
Litigation	11. Litigation Savant Litigation On July 10, 2017, the Company filed a complaint against Savant in the Superior Court for the State of Delaware, New Castle County (the “Delaware Court”). KaloBios Pharmaceuticals, Inc. v. Savant Neglected Diseases, LLC On July 12, 2017, Savant removed the case to the Bankruptcy Court, claiming that the action is related to or arises under the Bankruptcy Case from which we emerged in July 2016. In re KaloBios Pharmaceuticals, Inc. On August 2, 2017, Savant sent a foreclosure notice to the Company, demanding that it provide the Collateral as defined in the Security Agreement for inspection and possession on August 9, 2017, with a public sale to be held on September 1, 2017. The Company moved for a Temporary Restraining Order (the “TRO”) and Preliminary Injunction in the Bankruptcy Court on August 4, 2017. Savant responded on August 7, 2017. On August 7, 2017, the Bankruptcy Court granted the Company’s motion for a TRO, entering an order prohibiting Savant from collecting on or selling the Collateral, entering our premises, issuing any default notices to us, or attempting to exercise any other remedies under the MDC Agreement or the Security Agreement. On August 9, 2017, the parties have stipulated to continue the provisions of the TRO in full force and effect until further order of the appropriate court, which the Bankruptcy Court signed that same day (the “Stipulated Order”). On January 22, 2018, Savant wrote to the Bankruptcy Court requesting dissolution of the TRO and the Stipulated Order. On January 29, 2018, the Bankruptcy Court granted the Motion to Remand and denied Savant’s request to dissolve the TRO and Stipulated Order, ordering that any request to dissolve the TRO and Stipulated Order be made to the Delaware Court. On February 13, 2018 Savant made a letter request to the Delaware Court to dissolve the TRO and Stipulated Order. Also, on February 13, 2018, the Company filed its Answer and Affirmative defenses to Savant’s Counterclaims. On February 15, 2018 the Company filed a letter opposition to Savant’s request to dissolve the TRO and Stipulated Order and requesting a status conference. A hearing on Savant’s request to dissolve the TRO and Stipulated Order was held before the Delaware Court on March 19, 2018. The Delaware Court denied Savant’s request to dissolve the TRO and Stipulated order, which remain in effect. On April 11, 2018, the Company advised the Delaware Court that it would meet and confer with Savant regarding a proposed case management order and date for trial. On April 26, 2018 the Delaware Court so-ordered a proposed case management order submitted by the Company and Savant. The schedule in the case management order was modified by stipulation on August 24, 2018. On April 8, 2019, the Company moved to compel Savant to produce documents in response to the Company’s document requests. The parties thereafter agreed to a discovery schedule through June 30, 2019, which the Superior Court so ordered, and the parties produced documents to each other. On June 4, 2019, Savant filed a complaint against the Company and Madison in the Delaware Court of Chancery (the “Chancery Action”) seeking to “recover as damages that amounts owed to it under the MDC Agreement, and to reclaim Savant’s intellectual property,” among other things. Savant also requested leave to move to dismiss the Company’s complaint on the grounds that the Company’s transfer of assets to Madison was champertous. On June 10, 2019, the Company requested by letter that the Superior Court hold a contempt hearing because the Chancery Action violated the TRO entered by the Bankruptcy Court, the terms of which have been extended by stipulation of the parties. On June 18, 2019, the Superior Court held a telephonic status conference. The parties agreed that the Chancery Action should be consolidated with the Superior Court action, after which the Superior Court would address the parties’ motions. On July 22, 2019, the Company moved for contempt against Savant. Savant filed its opposition on July 29, 2019. On August 12, 2019, the Superior Court denied the Company’s motion for contempt. On July 23, 2019, Savant moved for summary judgment on the issue of champerty. The Company filed its response and cross-motion for summary judgment on August 27, 2019. Savant filed its reply on September 10, 2019 and the Company filed its cross-reply on September 20, 2019. The motion is fully briefed and was argued at a hearing on February 3, 2020. On August 17, 2020 the Superior Court issued a memorandum opinion denying Savant’s motion for summary judgment on the issue of champerty. On July 26, 2019, the Company moved to modify the previously agreed-upon discovery schedule to extend discovery through December 31, 2019, which the Superior Court granted. In subsequent orders, the discovery schedule was further extended until the end of June 2020. On July 30, 2019, the Company filed a motion to dismiss Savant’s Chancery Action. Savant filed an amended complaint on September 4, 2019, and the Company filed its opening brief in support of its motion to dismiss on October 11, 2019. That motion is fully briefed and was argued at a hearing on February 3, 2020. On August 17, 2020 the Superior Court issued a memorandum opinion denying the Company’s motion to dismiss Savant’s Chancery Action. On August 19, 2019, Savant moved to dismiss the Company’s amended Superior Court complaint. On September 27, 2019, the Company filed an opposition to Savant’s motion and, in the alternative, requested leave to file a second amended complaint against Savant. Savant consented to the filing of the second amended complaint and withdrew their motion to dismiss. Savant filed a partial motion to dismiss against a co-defendant on October 30, 2019. That motion is fully briefed and was argued at a hearing on February 3, 2020. At the February 3, 2020 hearing, the Court reserved judgment on the parties’ reciprocal motions. On August 17, 2020, the Superior Court issued a memorandum opinion granting in part and denying in part the Savant’s motion to dismiss the Company’s amended Superior Court complaint. The Superior Court found the Company lacked standing because it assigned its interest to its co-plaintiff Madison Joint Venture LLC (“Madison”). However, the Superior Court found that Madison had standing to proceed. Although the Company was dismissed from all counts of the Superior Court Action it continues to possess an interest in the Superior Court Action because of its ownership of Madison and remains a litigant because of Savant’s Chancery Action. Savant’s motion to dismiss the Company’s amended Superior Court complaint was denied in all other respects. On May 22, 2020, upon the request of the parties, the Superior Court stayed both Delaware actions until July 29, 2020. On June 30, 2020, Savant exercised 100,000 warrants in a cashless exercise resulting in 54,545 shares being issued to Savant. On July 24, 2020, the parties submitted a joint status report in the Delaware actions. The parties also requested a status conference with the Court to discuss moving the trial from October 2020 to some later time. On August 20, 2020, the Court held the requested status conference and ordered that a consolidated trial for the Superior Court Action and Chancery Action would be held in April 2021. The parties subsequently agreed to a five-day trial starting on April 12, 2021. On September 29, 2020, upon the request of the parties, the Superior Court revised the existing discovery schedule. Under the revised discovery schedule fact discovery closed on November 9, 2020 and expert discovery closed on December 18, 2020. On October 7, 2020, Savant moved for leave to amend its complaint in the Chancery Action to add a claim for breach of contract related to its exercise of 100,000 warrants on June 30, 2020. Savant claims that the Company’s issuance of 54,545 shares was insufficient under the warrant. On November 23, 2020, the Superior Court granted Savant’s motion for leave to amend its complaint in the Chancery Action. The Company answered the second amended complaint in the Chancery Action on December 11, 2020. On November 30, 2020, the Superior Court revised the discovery schedule to permit the Company to take additional discovery regarding Savant’s second amended complaint in the Chancery Action. Under this revised schedule, the Company had until December 18, 2020 to take additional discovery. Further, the deadline to complete expert discovery was moved to January 5, 2021. A consolidated trial for the Superior Court Action and Chancery Action remains scheduled for April 2021. On December 18, 2020, fact discovery closed. On January 5, 2021, the Company moved for leave to amend the Superior Court complaint to add Scott Freeman as a defendant. Savant opposed the motion for leave to amend on February 5, 2021. Briefing was completed on March 5, 2021. Further, the deadline for expert discovery closed. On January 19, 2021, the Company and Savant filed competing motions for summary judgment on their respective claims in the Superior Court Action and Chancery Action. Oppositions to the motions for summary judgment were filed on February 5, 2021 and replies were filed on February 24, 2021. Briefing is now complete and a hearing is scheduled for March 18, 2021. Private Placement Litigation On June 15, 2020, a complaint was filed against the Company and Dr. Durrant in the Commercial Division of the Supreme Court of the State of New York. The case caption is Alliance Texas Holdings, LLC et al. v. Humanigen, Inc. et al. On June 19, 2020, Noble filed a separate complaint against the Company in the Circuit Court of the Fifteenth Judicial Circuit in and for Palm Beach County, Florida, also arising from the Private Placement. On July 13, 2020, the Defendants removed Noble’s complaint to United States District Court for the Southern District of Florida. The case caption is Noble Capital Markets, Inc. v. Humanigen, Inc. The Company believes that the claims made in each complaint are without merit, and it is prepared to defend itself vigorously.

License and Collaboration Agree

License and Collaboration Agreements	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
License and Collaboration Agreements	12. License and Collaboration Agreements Kite Agreement On May 30, 2019, the Company entered into a collaboration agreement (the “Kite Agreement”) with Kite Pharmaceuticals, Inc., pursuant to which the Company and Kite are conducting a multi-center Phase 1b/2 study of lenzilumab with Kite’s Yescarta in patients with relapsed or refractory B-cell lymphoma, including diffuse large B-cell lymphoma (“DLBCL”). The primary objective of the study is to determine the effect of lenzilumab on the safety of Yescarta. Pursuant to the Kite Agreement, the Company shall supply lenzilumab to the collaboration for use in the study and will contribute up to approximately $8.0 million towards the out-of-pocket costs of the study, depending on the number of patients enrolled into the study. During the month of September 2020, the Company paid $2.0 million to Kite towards its contribution for the study, which payment was recorded as Research and development expense in the year ended December 31, 2020. Mayo Agreement On June 19, 2019 the Company entered into an exclusive worldwide license agreement (the “Mayo Agreement”) with the Mayo Foundation for Medical Education and Research (“Mayo”) for certain technologies used to create CAR-T cells lacking GM-CSF expression through various gene-editing tools including CRISPR-Cas9 (GM-CSF knock-out). The license covers various patent applications and know-how developed by Mayo in collaboration with the Company. These licensed technologies complement and broaden the Company’s position in the GM-CSF neutralization space and expand the Company’s discovery platform aimed at improving CAR-T to include gene-edited CAR-T cells. Pursuant to the Mayo Agreement, the Company agreed to pay $200,000 to Mayo within six months of the effective date, or upon completion of a qualified financing, whichever is earlier. The Mayo Agreement also requires the payment of milestones and royalties upon the achievement of certain regulatory and commercialization milestones. The initial payment was recorded as Research and development expense in June 2019. The Company paid the initial payment in June 2020 subsequent to the closing of the Private Placement. Zurich Agreement On July 19, 2019 the Company entered into an exclusive worldwide license agreement (the “Zurich Agreement”) with the University of Zurich (“UZH”) for technology used to prevent or treat Graft versus Host Disease (“GvHD”) through GM-CSF neutralization. The Zurich Agreement covers various patent applications filed by UZH which complement and broaden the Company’s position in the application of GM-CSF and expands the Company’s development platform to include improving allogeneic Hematopoietic Stem Cell Transplantation (“HSCT”). Pursuant to the Zurich Agreement, the Company paid $100,000 to UZH in July 2019. The Zurich Agreement also requires the payment of annual maintenance fees and milestones and royalties upon the achievement of certain regulatory and commercialization milestones. The license payment of $100,000 was recorded as Research and development expense in July 2019. CRADA On November 5, 2020, the Company and the Department of Defense (DoD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND or JPEO) entered into a Cooperative Research and Development Agreement (“CRADA”) in collaboration with the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response (ASPR) at the U.S. Department of Health and Human Services (HHS), in support of OWS, to assist in the development of the Company’s lead product candidate, lenzilumab, in advance of a potential EUA for COVID-19. On January 22, 2021, the Company announced an expansion of the CRADA that it had previously entered with JPEO on November 5, 2020, was subsequently co-signed by BARDA. This provides the Company with access to manufacturing capacity reserved by BARDA for fill-finish product to accelerate the drug product manufacturing of lenzilumab. Pursuant to the CRADA, the Company has been provided access to a full-scale, integrated team of OWS manufacturing, and regulatory subject matter experts, leading decision makers and statistical support in anticipation of applying for EUA and subsequently a BLA for lenzilumab as a potential treatment for COVID-19. The CRADA also provides that OWS regulatory experts will work with the Company on FDA communications, meetings and regulatory filings. The CRADA aims to support the lenzilumab Phase 3 clinical trial output, focusing on efficiently generating an EUA and BLA submission. In addition to providing access under EUA, a goal of the CRADA is to ensure lenzilumab receives the benefits provided by Public Law 115-92. Manufacturing Agreements During the year ended December 31, 2020 the Company has entered into agreements with several contract manufacturing organizations (“CMOs”) to have them manufacture bulk drug substance (“BDS”) for our lenzilumab clinical trial activities in COVID-19 as well as to manufacture BDS for a potential launch of lenzilumab in anticipation of an EUA in 2021. We have also entered into agreements for filling, finishing and packaging of the drug. These agreements represent large commitments, including upfront amounts prior to commencement of manufacturing and progress payments through the course of the manufacturing process and include payments for technology transfer. As of December 31, 2020, the Company estimates that its commitments to be incurred during the first quarter of 2021 will amount to approximately $48 million. The agreements contain customary cancellation clauses.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions Commencing September 19, 2018, the Company delivered a series of convertible promissory notes evidencing an aggregate of $2.5 million of loans made to the Company by six different lenders, including an affiliate of BHC, the Company’s controlling stockholder. See Note 6 for a further discussion of the 2018 Notes. On June 28, 2019, the Company issued three short-term, secured bridge notes evidencing an aggregate of $1.7 million of loans made to the Company by three parties including Dr. Cameron Durrant, our Chairman and Chief Executive Officer and Cheval Holdings, Ltd., an affiliate of Black Horse Capital, L.P., our controlling stockholder. See Note 6 for a further discussion of the 2019 Bridge Notes. On November 12, 2019, the Company issued two short-term, secured bridge notes (the “November Bridge Notes” and together with the June Bridge Notes, the “2019 Bridge Notes”) evidencing an aggregate of $350,000 of loans made to the Company by two parties, including Dr. Cameron Durrant, our Chairman and Chief Executive Officer and Cheval Holdings, Ltd., an affiliate of Black Horse Capital, L.P., our controlling stockholder. See Note 6 for a further discussion of the 2019 Bridge Notes.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Eversana Agreement On January 10, 2021, the Company announced that it had entered into a master services agreement (the “Eversana Agreement”) with Eversana Life Science Services, LLC (“Eversana”) pursuant to which Eversana will provide the Company multiple services from its integrated commercial platform in preparation for the potential commercialization of lenzilumab, the Company’s lead product candidate, for treatment of hospitalized and hypoxic COVID-19 patients. Under the Eversana Agreement, Eversana will serve as the Company’s end-to-end commercial partner, providing the Company with a full suite of services in connection with the potential launch of lenzilumab. Eversana services initially will comprise marketing, market access and field solution services, and may expand to other areas including patient services, compliance services, professional services, data and analytics, and health economics outcome research, as may be negotiated by the parties and set forth in statements of work delivered in accordance with the Eversana Agreement. The Company will pay Eversana fees and reimburse it for its expenses in performing the services as established in applicable statements of work. Eversana has agreed to defer its fees pending the Company’s receipt of an EUA from the U.S. Food and Drug Administration for lenzilumab for hospitalized and hypoxic COVID-19 patients. If the Company has not received an EUA by April 30, 2021 or such later date as to which the parties otherwise may agree, either party may terminate the Agreement immediately; Eversana will not receive the deferred fees upon such termination. The Eversana Agreement provides for a one-year term and will renew for subsequent one-year terms unless either party provides a notice of non-renewal. After the first year, the Company may terminate the Eversana Agreement upon advance written notice to Eversana. The Eversana Agreement contains customary provisions allowing either party to terminate the Eversana Agreement as a result of certain changes in law and material breaches and certain insolvency events by or relating to the other party. The Eversana Agreement imposes customary mutual obligations on the parties to protect and not disclose the confidential information and intellectual property of the other, and contains insurance, non-solicitation, indemnification and limitation of liability provisions customary for service contracts of this type. CRADA Amendment On January 22, 2021, the Company announced an expansion to the Cooperative Research and Development Agreement (as amended and restated, the “CRADA”) that the Company had previously entered into with the Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND), to gain access to manufacturing capacity reserved by the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response (ASPR) at the U.S. Department of Health and Human Services. The CRADA supports development of the Company’s lead product candidate, lenzilumab, in advance of a potential Emergency Use Authorization (“EUA”) for COVID-19. The CRADA, now co-signed by BARDA, provides the Company with access to manufacturing capacity reserved by BARDA for fill-finish product to accelerate the drug product manufacturing of lenzilumab. The initial agreement, originally signed in November 2020 and amended and restated on January 21, 2021, complements the Company’s development efforts for lenzilumab by providing access to a full-scale, integrated team of manufacturing and regulatory subject matter experts and statistical support in anticipation of applying for EUA and subsequently a Biologics License Application (“BLA”) for lenzilumab as a potential treatment for COVID-19. Enrollment Completion On January 29, 2021, the Company announced that it had completed enrollment for its pivotal Phase 3 study of lenzilumab TM for COVID-19. Controlled Equity Offering Sales During the period from January 1, 2021 through March 5, 2021, the Company sold 1,796,858 shares of its common stock under the Sales Agreement for net proceeds of $36.2 million. Secured Term Loan Facility On March 10, 2021, we executed a Loan and Security Agreement with Hercules Capital, Inc., as agent for its affiliates serving as lenders thereunder, pursuant to which we established a term loan facility in aggregate principal amount of up to $80 million (the “Term Loan”). The Term Loan provides us with the ability to draw an initial amount of $25.0 million, with up to an additional $55.0 million available for future draws subject to achievement of future milestones and satisfaction of other conditions. See Part II, Item 9B “Other Information” for additional information regarding the Term Loan.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include all adjustments necessary for the presentation of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. The Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiaries. These financial statements have been prepared on a basis that assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the Consolidated Financial Statements and accompanying notes. Actual results could differ materially from those estimates. The Company believes judgment is involved in accounting for the fair value-based measurement of stock-based compensation, accruals, convertible notes and warrants. The Company evaluates its estimates and assumptions as facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from these estimates and assumptions, and those differences could be material to the Consolidated Financial Statements.
Concentration of Credit Risk	Concentration of Credit Risk Cash, cash equivalents, and marketable securities consist of financial instruments that potentially subject the Company to a concentration of credit risk in the event of a default by the related financial institution holding the securities, to the extent of the value recorded in the balance sheet. The Company invests cash that is not required for immediate operating needs primarily in highly liquid instruments with lower credit risk. The Company has established guidelines relating to the quality, diversification, and maturities of securities to enable the Company to manage its credit risk.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking, interest-bearing and demand money market accounts.
Restricted Cash	Restricted Cash Restricted cash at December 31, 2020 and 2019 of $70 thousand and $71 thousand, respectively, relates to a standby letter of credit in the amount of approximately $50 thousand issued in connection with certain insurance policy coverage maintained by the Company and restricted cash related to a credit card facility in the amount of approximately $20 thousand.
Debt Issue Costs	Debt Issue Costs Debt issuance costs related to a recognized debt liability are presented on the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and are amortized to interest expense over the term of the related debt using the effective interest method.
Research and Development Expenses	Research and Development Expenses Development costs incurred in the research and development of new product candidates are expensed as incurred, including expenses that may or may not be reimbursed under research and development collaboration arrangements. Research and development costs include, but are not limited to, salaries, benefits, stock-based compensation, laboratory supplies, allocated overhead, fees for professional service providers and costs associated with product development efforts, including preclinical studies and clinical trials. The Company estimates preclinical study and clinical trial expenses based on the services performed, pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on its behalf. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Payments made to third parties under these arrangements in advance of the receipt of the related services are recorded as prepaid expenses until the services are rendered. The Company records upfront and milestone payments made to third parties under licensing arrangements as an expense. Upfront payments are recorded when incurred and milestone payments are recorded when the specific milestone has been achieved.
Revenue Recognition	Revenue Recognition The Company’s revenue to date has been generated primarily through license agreements and research and development collaboration agreements. The Company recorded $0.3 million for the year ending December 31, 2020 related to a licensing agreement dated November 3, 2020 (See Note 3 – License Revenue) and had no revenues for the year ending December 31, 2019. Commencing January 1, 2018, the Company recognizes revenue in accordance with FASB Accounting Standards Codification (“ASC”) Topic 606 – Revenue from Contracts with Customers Revenue under technology licenses and collaborative agreements typically consists of nonrefundable and/or guaranteed license fees, collaborative research funding, and various milestone and future product royalty or profit-sharing payments. The fair value of deliverables under the arrangement may be derived using a best estimate of selling price if vendor specific objective evidence and third-party evidence is not available. Deliverables under the arrangement will be separate units of accounting if a delivered item has value to the customer on a standalone basis and if the arrangement includes a general right of return for the delivered item, delivery or performance of the undelivered item is considered probable and substantially in the Company’s control. The Company recognizes upfront license payments as revenue upon delivery of the license only if the license has standalone value from any undelivered performance obligations and that value can be determined. The undelivered performance obligations typically include manufacturing or development services or research and/or steering committee services. If the fair value of the undelivered performance obligations can be determined, then these obligations would be accounted for separately. If the license is not considered to have standalone value, then the license and other undelivered performance obligations would be accounted for as a single unit of accounting. In this case, the license payments and payments for performance obligations are recognized as revenue over the estimated period of when the performance obligations are performed or deferred indefinitely until the undelivered performance obligation is determined. Whenever the Company determines that an arrangement should be accounted for as a single unit of accounting, the Company determines the period over which the performance obligations will be performed, and revenue will be recognized. Revenue is recognized using a proportional performance or straight-line method. The proportional performance method is used when the level of effort required to complete performance obligations under an arrangement can be reasonably estimated. The amount of revenue recognized under the proportional performance method is determined by multiplying the total payments under the contract, excluding royalties and payments contingent upon achievement of milestones, by the ratio of the level of effort performed to date to the estimated total level of effort required to complete performance obligations under the arrangement. If the Company cannot reasonably estimate the level of effort to complete performance obligations under an arrangement, the Company recognizes revenue under the arrangement on a straight-line basis over the period the Company is expected to complete its performance obligations. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which the Company is expected to complete its performance obligations under an arrangement. The Company’s collaboration agreements typically entitle the Company to additional payments upon the achievement of development, regulatory and sales performance-based milestones. If the achievement of a milestone is considered probable at the inception of the collaboration, the related milestone payment is included with other collaboration consideration, such as upfront fees and research funding, in the Company’s revenue calculation. Typically, these milestones are not considered probable at the inception of the collaboration. As such, milestones will typically be recognized in one of two ways depending on the timing of when the milestone is achieved. If the milestone is achieved during the performance period, then the Company will only recognize revenue to the extent of the proportional performance achieved at that date, or the proportion of the straight-line basis achieved at that date, and the remainder will be recorded as deferred revenue to be amortized over the remaining performance period. If the milestone is achieved after the performance period has completed and all performance obligations have been delivered, then the Company will recognize the milestone payment as revenue in its entirety in the period the milestone was achieved. See Note 3 for information on the 2020 Korea License Agreement.
Leases	Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. The FASB subsequently issued ASU No. 2018-10 and 2018-11 in July 2018, which provide clarifications and improvements to ASU 2016-02 (collectively, the “new lease standard”). ASU No. 2018-11 provides the optional transition method which allows companies to apply the new lease standard at the adoption date instead of at the earliest comparative period presented and continue to apply the provisions of the previous lease standard in its annual disclosures for the comparative periods. The new lease standard requires lessees to present a right-of-use asset and a corresponding lease liability on the balance sheet. Additional footnote disclosures related to leases are also required. On January 1, 2019, the Company adopted the new lease standard using the optional transition method and certain other practical expedients. Under the practical expedient package elected, the Company is not required to reassess whether expired or existing contracts are or contain a lease; and is not required to reassess the lease classifications or reassess the initial direct costs associated with expired or existing leases. The new lease standard also provides practical expedients for an entity’s ongoing accounting. The Company elected the short-term lease recognition exemption for all leases that qualify. This means, for those leases that qualify, we will not recognize right of use assets or lease liabilities, and this includes not recognizing right of use assets or lease liabilities for existing short-term leases of those assets in transition. The Company elected the practical expedient to not separate lease and non-lease components for certain classes of assets. During 2019 and a portion of 2020, the Company sub-leased office space under a short-term lease in Burlingame, California. On September 1, 2020 we entered into a one-year lease for a small office in the same building in Burlingame, California for $1,200 per month. Management has determined the lease term to be less than 12 months, including renewals, and therefore has not recorded a right-of-use asset and corresponding liability under the short-term lease recognition exemption. Lease costs for the years ended December 31, 2020 and 2019 totaled approximately $6,100 and $10,700, respectively and are included in the Consolidated Statements of Operations. Because the Company has elected to adopt the transitional practical expedients, Management was not required to reassess whether any existing or expired contracts contained embedded leases. The Company has not entered into any contracts during the 2020 fiscal year that contain an embedded lease.
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company measures stock-based compensation expense for stock awards at the grant date, based on the fair value-based measurement of the award, and the expense is recorded over the related service period, generally the vesting period, net of estimated forfeitures. The Company calculates the fair value-based measurement of stock options using the Black-Scholes valuation model and the single-option method and recognizes expense using the straight-line attribution approach.
Income Taxes	Income Taxes The Company accounts for income taxes under an asset-and-liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for tax and financial reporting purposes measured by applying enacted tax rates and laws that will be in effect when the differences are expected to reverse, net operating loss carryforwards and tax credits. Valuation allowances are provided when necessary to reduce net deferred tax assets to an amount that is more likely than not to be realized. The Company’s policy is to include interest and penalties related to unrecognized tax benefits within the Company’s provision for income taxes.
Net Loss Per Common Share	Net Loss Per Common Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, stock options, restricted stock units and common stock warrants are considered to be potentially dilutive securities but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented. The Company’s potential dilutive securities, which include stock options, restricted stock units and warrants have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per common share and be antidilutive. Therefore, the denominator used to calculate both basic and diluted net loss per common share is the same in all periods presented. The following shares subject to outstanding potentially dilutive securities have been excluded from the computations of diluted net loss per common share as the effect of including such securities would be antidilutive: Year Ended December 31, 2020 2019 Options to purchase common stock 3,728,149 3,176,336 Warrants to purchase common stock 51,238 66,238 3,779,387 3,242,574
Segment Reporting	Segment Reporting The Company determines its segment reporting based upon the way the business is organized for making operating decisions and assessing performance. The Company operates in only one segment, which is related to the development of pharmaceutical products.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of antidilutive securities excluded from computations of diluted net loss per common share	The following shares subject to outstanding potentially dilutive securities have been excluded from the computations of diluted net loss per common share as the effect of including such securities would be antidilutive: Year Ended December 31, 2020 2019 Options to purchase common stock 3,728,149 3,176,336 Warrants to purchase common stock 51,238 66,238 3,779,387 3,242,574

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Schedule of shares of common stock reserved for issuance	The Company has reserved the following shares of common stock for issuance as of December 31, 2020: Warrants to purchase common stock 51,238 Options: Outstanding under the 2020 Equity Incentive Plan 637,286 Outstanding under the 2012 Equity Incentive Plan 3,090,821 Outstanding under the 2001 Equity Incentive Plan 42 Available for future grants under the 2020 Equity Incentive Plan 6,349,911 10,129,298
Summary of stock option activity	The following table summarizes stock option activity for the years ended December 31, 2020 and 2019: Number of Weighted Average Price (per Weighted- Aggregate Outstanding at January 1, 2019 3,081,863 $ 4.75 Granted 294,191 3.90 Exercised (97,725 ) 3.35 Cancelled (forfeited) (101,984 ) 3.10 Cancelled (expired) (9 ) 48.40 Outstanding at December 31, 2019 3,176,336 4.75 Granted 981,164 7.35 Exercised (429,330 ) 3.55 Cancelled (expired) (21 ) 58.40 Outstanding at December 31, 2020 3,728,149 $ 5.57 7.6 $ 44,479 Options vested and expected to vest 3,715,473 $ 5.57 7.6 $ 44,328 Exercisable 2,999,502 $ 5.07 7.2 $ 10 ______________________ (1) The weighted average price per share is determined using exercise price per share for stock options. (2) The aggregate intrinsic value is calculated as the difference between the exercise price of the option and the fair value of the Company’s common stock for in-the-money options at December 31, 2020.
Schedule of stock options outstanding and exercisable by exercise price	The stock options outstanding and exercisable by exercise price at December 31, 2020 are as follows: Stock Options Outstanding Stock Options Exercisable Range of Exercise Prices Number Weighted- Weighted- Number of Weighted- $1.65 - $3.33 2,534,965 7.30 $ 3.14 2,372,837 $ 3.18 $4.20 - $9.05 343,065 8.95 $ 6.30 176,190 $ 4.92 $9.65 - $16.50 587,286 9.31 $ 10.57 187,642 $ 12.53 $16.90 - $16.90 252,604 5.62 $ 16.90 252,604 $ 16.90 $17.00 - $18.00 10,125 5.72 $ 17.01 10,125 $ 17.01 $58.40 - $86.80 42 0.09 $ 67.87 42 $ 67.87 $216.40 - $240.00 62 0.12 $ 225.92 62 $ 225.92 3,728,149 7.65 $ 5.57 2,999,502 $ 5.07
Schedule of fair value-based measurement of stock options granted under the entity's stock plans estimated using Black-Scholes model	The weighted-average fair value-based measurement of stock options granted under the Company’s stock plans in the years ended December 31, 2020 and 2019 was $7.35 and $3.95 per share, respectively. The fair value- based measurement of stock options granted under the Company’s stock plans was estimated at the date of grant using the Black-Scholes model with the following assumptions: Year Ended December 31, 2020 2019 Expected term 5 - 6 years 5 - 6 years Expected volatility 95% - 111% 96% - 99% Risk-free interest rate 0.28% - 1.57% 1.74% - 2.59% Expected dividend yield 0% 0%
Schedule of total stock-based compensation expense recognized	Total expense for stock option grants recognized was as follows: Year ended December 31, 2020 2019 Selling,general and administrative $ 1,773 $ 1,928 Reseach and development 337 97 Total stock-based compensation $ 2,110 $ 2,025

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of significant components of deferred tax assets	Deferred tax assets and liabilities reflect the net tax effects of net operating loss and tax credit carryovers and the temporary differences between the carrying amounts of assets and liabilities for financial reporting and the amounts used for income tax purposes. Significant components of the Company's deferred tax assets are as follows: As of December 31, 2020 2019 Deferred tax assets: Net operating losses $ 75,149 $ 50,144 Research and other credits 2,178 2,178 Stock based compensation 3,256 3,001 In-Process research and development 1,193 1,253 Other 665 854 Total deferred tax assets 82,441 57,430 Valuation allowance (82,441 ) (57,430 ) Net deferred tax assets $ - $ -
Schedule of reconciliation of the statutory tax rates and the effective tax rates	A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 2020 and 2019 is as follows: Year Ended December 31, 2020 2019 Statutory rate 21.0 % 21.0 % Valuation allowance (27.9 )% (26.0 )% Nondeductible stock compensation - % (0.3 )% Other 6.9 % 5.3 % Effective tax rate - % - %
Reconciliation of beginning and ending amount of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: Balance at December 31, 2018 $ 1,060 Additions based on tax positions related to prior year - Additions based on tax positions related to current year - Balance at December 31, 2019 1,060 Additions based on tax positions related to prior year - Additions based on tax positions related to current year - Balance at December 31, 2020 $ 1,060

Organization and Description _2

Organization and Description of Business (Details) - USD ($) $ in Thousands	Mar. 05, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and cash equivalents			$ 67,737	$ 143
Proceeds from issuance of common stock			$ 139,760	$ 185
Subsequent Event [Member]
Payment for clinical trial support services		$ 58,000
Cash and cash equivalents	$ 74,300
Proceeds from issuance of common stock	$ 36,200

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Summary of Significant Accounting Policies [Line Items]
Restricted cash current, standby letters of credit	$ 70,000	$ 71,000
Issuance of letters of credit for insurance policy coverage	50,000	50,000
Restricted cash related credit card facility	$ 20,000	20,000
Number of operating segments	1
Short-term lease amount per month	$ 1,200
Lease costs	6,100	$ 10,700
License Agreement Terms [Member]
Summary of Significant Accounting Policies [Line Items]
License Revenue	$ 300,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Potentially Dilutive Securities) (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 computations of diluted net loss per common share	3,779,387	3,242,574
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computations of diluted net loss per common share	3,728,149	3,176,336
Warrants to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computations of diluted net loss per common share	51,238	66,238

License Revenue (Details)

License Revenue (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
License Agreement Terms [Member]
Gross up-front license fee	$ 6,000,000
Aggregate licence payment received	$ 14,000,000
Description of licensing agreement	The Company will supply lenzilumab to the Licensee for a minimum of 7.5 years at a cost-plus basis from an existing or future manufacturer.
Revenue recognized performance obligation description of payment	Over the 29-month period through March of 2023 (the “Performance Period”), the expected period over which the Company conservatively expects the Services to be performed with approval in the Territory expected by the end of March 2023.
License revenue	$ 300,000
Up-front Payment Arrangement [Member]
Upfront payment	$ 4,500,000

Savant Arrangements (Details)

Savant Arrangements (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 10, 2017	May 26, 2017	Jun. 30, 2016	Dec. 31, 2020	Dec. 31, 2019
Number of shares called by warrant				51,238	331,193
Research and development	$ 1,000	$ 1,000		$ 72,713	$ 2,616
Due to Savant				$ 2,000	$ 2,000
Savant Neglected Diseases, LLC [Member]
Number of shares called by warrant			200,000
Exercise price of warrant			$ 2.25
Exercise period of warrant			5 years

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands

Apr. 02, 2020

Mar. 13, 2020

Nov. 12, 2019

Jul. 02, 2019

Apr. 30, 2020

Mar. 19, 2020

May 30, 2019

Sep. 19, 2018

Aug. 31, 2018

Jun. 28, 2019

Dec. 31, 2020

Dec. 31, 2019

Aug. 31, 2019

Apr. 23, 2019

Jun. 30, 2016

Debt Instrument [Line Items]

Proceeds from advance notes

$ 900

Percentage of accrued interest

7.00%

Intrinsic value of this beneficial conversion feature

$ 143

Proceeds from convertible debt

$ 467

1,275

Advance Notes [Member]

Debt Instrument [Line Items]

Conversion price

$ 2.25

Issuance of common stock upon note conversions shares

435,924

2019 Bridge Notes [Member]

Debt Instrument [Line Items]

Term loan interest rate

7.00%

Debt instrument amount

$ 1,700

Proceeds from advance notes

$ 750

Interest expense debt

$ 66

2019 Bridge Notes [Member] | Bona fide financing [Member]

Debt Instrument [Line Items]

Proceeds from advance notes

$ 10,000

3,000

2019 Bridge Notes [Member] | November Bridge Notes [Member]

Debt Instrument [Line Items]

Interest rate

7.00%

7.00%

Debt instrument amount

$ 350

$ 350

Maturity Date

Dec. 31, 2020

Dec. 31, 2020

2019 Bridge Notes [Member] | November Bridge Notes [Member] | Cheval Holdings [Member]

Debt Instrument [Line Items]

Debt instrument amount

$ 250

2019 Bridge Notes [Member] | Cameron Durrant [Member] | November Bridge Notes [Member]

Debt Instrument [Line Items]

Debt instrument amount

$ 100

2019 Bridge Notes [Member] | Cheval [Member] | November Bridge Notes [Member]

Debt Instrument [Line Items]

Debt instrument amount

$ 100

2019 Bridge Notes [Member] | Nomis Bay [Member] | November Bridge Notes [Member]

Debt Instrument [Line Items]

Debt instrument amount

$ 250

2019 Bridge Notes [Member] | Advance Notes [Member]

Debt Instrument [Line Items]

Proceeds from advance notes

950

2019 Bridge Notes [Member] | Nomis Bay LTD [Member]

Debt Instrument [Line Items]

Debt instrument amount

750

2019 Bridge Notes [Member] | Cameron Durrant [Member]

Debt Instrument [Line Items]

Debt instrument amount

750

2019 Bridge Notes [Member] | Chief Executive Officer [Member]

Debt Instrument [Line Items]

Debt instrument amount

$ 200

2019 Bridge Notes [Member] | Bona Fide Financing Transaction [Member]

Debt Instrument [Line Items]

Proceeds from advance notes

$ 3,000

2018 Convertible Notes Payable [Member] | Advance Notes [Member]

Debt Instrument [Line Items]

Common stock conversion price

$ 2.25

Intrinsic value of this beneficial conversion feature

$ 1,800

Debt discount amortization

785

2018 Convertible Notes Payable [Member] | Non Qualified Financing [Member]

Debt Instrument [Line Items]

Proceeds from convertible debt

$ 10,000

Conversion price

$ 2.25

Black Horse Capital LP [Member] | Convertible Promissory Note [Member]

Debt Instrument [Line Items]

Term loan interest rate

7.00%

Debt instrument amount

$ 2,500

2019 Convertible Notes Payable [Member]

Debt Instrument [Line Items]

Accrued interest

100

Term loan interest rate

7.50%

Debt instrument amount

$ 1,300

Interest expense debt

219

Proceeds from convertible debt

$ 4,300

Issuance of common stock upon note conversions shares

2,397,915

2019 Convertible Notes Payable [Member] | Cheval. Dr. Dale Chappell [Member]

Debt Instrument [Line Items]

Issuance of common stock upon note conversions shares

316,666

2019 Convertible Notes Payable [Member] | Advance Notes [Member]

Debt Instrument [Line Items]

Common stock conversion price

$ 6.25

Intrinsic value of this beneficial conversion feature

$ 1,800

Debt discount amortization

785

2019 Convertible Notes Payable [Member] | Non Qualified Financing [Member]

Debt Instrument [Line Items]

Proceeds from convertible debt

$ 10,000

Conversion price

$ 6.25

2020 Convertible Redeemable Notes [Member]

Debt Instrument [Line Items]

Notes payable to vendors

$ 518,333

Term loan interest rate

7.00%

Debt discount amortization

$ 52

Interest expense debt

$ 165

Debt instrument redemption description

The notes could be redeemed by the Company at any time before the 270th day following issuance, at a redemption price equal to the principal and accrued but unpaid interest on the notes to the date of redemption, plus a premium that increases on day 61 and day 121 from the issuance date. Accordingly, the notes were repaid in June 2020 with proceeds from the Private Placement, and the notes were extinguished.

Fair value of convertible notes

$ 0

2020 Convertible Redeemable Notes [Member] | Tranche One [Member]

Debt Instrument [Line Items]

Maturity Date

Mar. 13, 2021

Debt issue discount

$ 33,000

2020 Convertible Redeemable Notes [Member] | Tranche Two [Member]

Debt Instrument [Line Items]

Maturity Date

Mar. 19, 2021

Debt issue discount

$ 18,833

Notes Payable To Vendors [Member]

Debt Instrument [Line Items]

Interest rate

10.00%

Notes payable to vendors

$ 1,200

Accrued interest

300

Notes Payable To Vendors [Member] | 2019 Bridge Notes [Member]

Debt Instrument [Line Items]

Accrued interest

1,100

Debt instrument amount

$ 500

Notes Payable To Vendors [Member] | 2018 Convertible Notes Payable [Member]

Debt Instrument [Line Items]

Accrued interest

200

Interest expense debt

$ 817

Warrants to Purchase Common S_2

Warrants to Purchase Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands

Sep. 14, 2020

Jun. 30, 2021

May 20, 2020

Apr. 22, 2020

Jun. 30, 2016

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2017

Jul. 30, 2020

Jun. 30, 2020

Dec. 04, 2015

Jun. 19, 2013

Class of Warrant or Right [Line Items]

Issuance of warrant to purchase shares of common stock

51,238

331,193

Reduction of expense warrant

$ 100

Number of warrants exercisable

2,999,502

Proceeds from warrants excercises

$ 10

Warrant [Member]

Class of Warrant or Right [Line Items]

Issuance of warrant to purchase shares of common stock

25,000

1,238

Exercise price of warrants issued (in dollars per share)

$ 146.60

$ 484.80

Options vested

20,000

Options not vested

20,000

Warrant [Member] | Investor Relation Services [Member]

Class of Warrant or Right [Line Items]

Issuance of warrant to purchase shares of common stock

200,000

4,000

8,000

Exercise price of warrants issued (in dollars per share)

$ 0.05

$ 0.05

$ 0.05

Term of issuance of warrant

8 years

8 years

8 years

Vesting period

2 years

2 years

2 years

Proceeds from warrants excercises

$ 10,000

$ 200

$ 400

Warrant [Member] | Manufacturing Consulting Services [Member]

Class of Warrant or Right [Line Items]

Issuance of warrant to purchase shares of common stock

30,000

Exercise price of warrants issued (in dollars per share)

$ 4.30

Term of issuance of warrant

10 years

Savant Warrant [Member]

Class of Warrant or Right [Line Items]

Issuance of warrant to purchase shares of common stock

40,000

10,909

Exercise price of warrants issued (in dollars per share)

$ 11.25

Warrants initial fair value

$ 700

Term of issuance of warrant

5 years

Percentage of warrant exercisable

25.00%

Number of warrants exercisable

20,000

Savant Warrant [Member] | Subsequent Event [Member]

Class of Warrant or Right [Line Items]

Number of warrants expire

$ 20,000

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Commitments [Line Items]
Rent expense	$ 3	$ 10
Future minimum lease payments	$ 10
Brisbane, California Lease [Member]
Other Commitments [Line Items]
Expiration date	Aug. 31, 2021
Burlingame, California Lease [Member]
Other Commitments [Line Items]
Expiration date	Mar. 31, 2020

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Sep. 17, 2020	Jan. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Sep. 11, 2020	Jul. 27, 2020	Nov. 08, 2019
Class of Stock [Line Items]
Reverse stock split			1-for-5
Common Stock, shares authorized upon the completion of the IPO			225,000,000	225,000,000	225,000,000
Common stock, par value			$ 0.001	$ 0.001
Common share issued			51,626,508	22,806,890
Total proceeds			$ 139,760	$ 185
Common stock, shares outstanding			51,626,508	22,806,890
Lincoln Park Capital Purchase Agreement [Member]
Class of Stock [Line Items]
Common stock, par value							$ 0.001
Value of right to sell number of shares							$ 20,000
Common share issued		140,000					141,318
Total proceeds		$ 300
Private Placement [Member]
Class of Stock [Line Items]
Common stock, par value			$ 4.35
Total proceeds			$ 71,800
Company issued shares			16,505,743
2020 Underwritten Public Offering [Member]
Class of Stock [Line Items]
Shares issued in public offering	9,200,000
Warrants to purchase common stock	78,200,000
2020 Underwritten Public Offering [Member] | J.P. Morgan Securities LLC and Jefferies LLC [Member]
Class of Stock [Line Items]
Shares issued in public offering	8,000,000
Warrants to purchase common stock	1,200,000
Controlled Equity OfferingSM Sales Agreement [Member] | Cantor Fitzgerald & Co. [Member]
Class of Stock [Line Items]
Common stock, par value			$ 0.001
Total proceeds			$ 100,000
2020 Equity Plan [Member]
Class of Stock [Line Items]
Shares available for future grant			6,349,911		7,000,000	7,000,000
Percentage of outstanding shares approved equity plan						63.00%
Maximum [Member]
Class of Stock [Line Items]
Common stock, shares outstanding					210,900,000
Minimum [Member]
Class of Stock [Line Items]
Common stock, shares outstanding					42,200,000

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Shares of Common Stock Reserved for Issuance) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants to purchase common stock	51,238	331,193
Total common stock reserved for future issuance	10,129,298
Total fair value of options vested	$ 2,200,000	$ 2,200,000
Weighted-average fair value of options granted during the period	$ 7.35	$ 3.95
Weighted-average period	2 years 3 months 19 days
Unrecognized compensation expense	$ 4,100,000
2020 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option outstanding	637,286
Available for future grants	6,349,911
2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option outstanding	3,090,821
Vesting period expiration	10 years
2012 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2012 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
2001 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option outstanding	42
2001 Stock Option Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be issued under the plan	426,030

Stockholders' Equity (Stock Opt

Stockholders' Equity (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Number of Shares
Balance at the beginning of the period (in shares)		3,176,336	3,081,863
Options granted (in shares)		981,164	294,191
Options exercised (in shares)		(429,330)	(97,725)
Options cancelled (forfeited) (in shares)			(101,984)
Options cancelled (expired) (in shares)		(21)	(9)
Balance at the end of the period (in shares)		3,728,149	3,176,336
Options vested and expected to vest at the end of the period (in shares)		3,715,473
Options exercisable (in shares)		2,999,502
Weighted-Average Exercise Price (per share)
Balance at the beginning of the period (in dollars per share)	[1]	$ 4.75	$ 4.75
Options granted (in dollars per share)	[1]	7.35	3.90
Options exercised (in dollars per share)	[1]	3.55	3.35
Options cancelled (forfeited) (in dollars per share)	[1]		3.10
Options cancelled (expired) (in dollars per share)	[1]	58.40	48.40
Balance at the ending of the period (in dollars per share)	[1]	5.57	$ 4.75
Options vested and expected to vest at the end of the period (in dollars per share)	[1]	5.57
Options exercisable (in dollars per share)	[1]	$ 5.07
Weighted-Average Remaining Contractual Term (in years)
Balance at the end of the period		7 years 7 months 6 days
Options vested and expected to vest at the end of the period		7 years 7 months 6 days
Options exercisable		7 years 2 months 12 days
Aggregate Intrinsic Value (in thousands)
Balance at the end of the period	[2]	$ 44,479
Options vested and expected to vest at the end of the period	[2]	44,328
Options exercisable	[2]	$ 10
[1]	The weighted average price per share is determined using exercise price per share for stock options.
[2]	The aggregate intrinsic value is calculated as the difference between the exercise price of the option and the fair value of the Company's common stock for in-the-money options at December 31, 2020.

Stockholders' Equity (Options O

Stockholders' Equity (Options Outstanding and Exercisable By Price Range) (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Stock Options Outstanding
Number of Shares | shares	3,728,149
Weighted Average Remaining Contractual Life	7 years 7 months 24 days
Weighted Average Exercise Price (in dollars per share)	$ 5.57
Stock Options Exercisable
Number of Shares | shares	2,999,502
Weighted Average Exercise Price Per Share (in dollars per share)	$ 5.07
Exercise Price Range From $1.65 - $3.33 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	1.65
Exercise Price, high end of range (in dollars per share)	$ 3.33
Stock Options Outstanding
Number of Shares | shares	2,534,965
Weighted Average Remaining Contractual Life	7 years 3 months 19 days
Weighted Average Exercise Price (in dollars per share)	$ 3.14
Stock Options Exercisable
Number of Shares | shares	2,372,837
Weighted Average Exercise Price Per Share (in dollars per share)	$ 3.18
Exercise Price Range From $4.20 - $9.05 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	4.20
Exercise Price, high end of range (in dollars per share)	$ 9.05
Stock Options Outstanding
Number of Shares | shares	343,065
Weighted Average Remaining Contractual Life	8 years 11 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 6.3
Stock Options Exercisable
Number of Shares | shares	176,190
Weighted Average Exercise Price Per Share (in dollars per share)	$ 4.92
Exercise Price Range From $9.65 - $16.50 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	9.65
Exercise Price, high end of range (in dollars per share)	$ 16.50
Stock Options Outstanding
Number of Shares | shares	587,286
Weighted Average Remaining Contractual Life	9 years 3 months 22 days
Weighted Average Exercise Price (in dollars per share)	$ 10.57
Stock Options Exercisable
Number of Shares | shares	187,642
Weighted Average Exercise Price Per Share (in dollars per share)	$ 12.53
Exercise Price Range From $16.90 - $16.90 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	16.90
Exercise Price, high end of range (in dollars per share)	$ 16.90
Stock Options Outstanding
Number of Shares | shares	252,604
Weighted Average Remaining Contractual Life	5 years 7 months 13 days
Weighted Average Exercise Price (in dollars per share)	$ 16.9
Stock Options Exercisable
Number of Shares | shares	252,604
Weighted Average Exercise Price Per Share (in dollars per share)	$ 16.9
Exercise Price Range From $17.00 - $18.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	17
Exercise Price, high end of range (in dollars per share)	$ 18
Stock Options Outstanding
Number of Shares | shares	10,125
Weighted Average Remaining Contractual Life	5 years 8 months 19 days
Weighted Average Exercise Price (in dollars per share)	$ 17.01
Stock Options Exercisable
Number of Shares | shares	10,125
Weighted Average Exercise Price Per Share (in dollars per share)	$ 17.01
Exercise Price Range From $58.40 - $86.80 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	58.40
Exercise Price, high end of range (in dollars per share)	$ 86.80
Stock Options Outstanding
Number of Shares | shares	42
Weighted Average Remaining Contractual Life	1 month 2 days
Weighted Average Exercise Price (in dollars per share)	$ 67.87
Stock Options Exercisable
Number of Shares | shares	42
Weighted Average Exercise Price Per Share (in dollars per share)	$ 67.87
Exercise Price Range From $216.40 - $240.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, low end of range (in dollars per share)	216.40
Exercise Price, high end of range (in dollars per share)	$ 240
Stock Options Outstanding
Number of Shares | shares	62
Weighted Average Remaining Contractual Life	1 month 13 days
Weighted Average Exercise Price (in dollars per share)	$ 225.92
Stock Options Exercisable
Number of Shares | shares	62
Weighted Average Exercise Price Per Share (in dollars per share)	$ 225.92

Stockholders' Equity (Fair Valu

Stockholders' Equity (Fair Value Assumptions) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Expected volatility, minimum (as a percent)	95.00%	96.00%
Expected volatility, maximum (as a percent)	111.00%	99.00%
Risk-free interest rate, minimum (as a percent)	0.28%	1.74%
Risk-free interest rate, maximum (as a percent)	1.57%	2.59%
Expected dividend yield (as a percent)	0.00%	0.00%
Minimum [Member]
Expected term	5 years	5 years
Maximum [Member]
Expected term	6 years	6 years

Stockholders' Equity (Stock-Bas

Stockholders' Equity (Stock-Based Compensation Expense Recognized) (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	$ 2,110	$ 2,025
General And Administrative Expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1,773	1,928
Research And Development Expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 337	$ 97

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (decrease) in valuation allowance	$ 25	$ 2.7
Internal Revenue Service I R S [Member]
Net operating loss carryforwards	166.2		$ 104.9
Internal Revenue Service I R S [Member] | Research [Member]
Tax credit carryforwards	$ 1.3
Internal Revenue Service I R S [Member] | Minimum [Member]
Expiration year	Dec. 31, 2021
Internal Revenue Service I R S [Member] | Minimum [Member] | Research [Member]
Expiration year	Dec. 31, 2022
Internal Revenue Service I R S [Member] | Maximum [Member]
Expiration year	Dec. 31, 2037
Internal Revenue Service I R S [Member] | Maximum [Member] | Research [Member]
Expiration year	Dec. 31, 2035
State And Local Jurisdiction [Member]
Net operating loss carryforwards	$ 261.4
State And Local Jurisdiction [Member] | Research [Member]
Tax credit carryforwards	$ 2.2
State And Local Jurisdiction [Member] | Minimum [Member]
Expiration year	Dec. 31, 2028
State And Local Jurisdiction [Member] | Maximum [Member]
Expiration year	Dec. 31, 2040

Income Taxes (Significant Compo

Income Taxes (Significant Components of Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating losses	$ 75,149	$ 50,144
Research and other credits	2,178	2,178
Stock based compensation	3,256	3,001
In-Process research and development	1,193	1,253
Other	665	854
Total deferred tax assets	82,441	57,430
Valuation allowance	(82,441)	(57,430)
Net deferred tax assets

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of the Statutory Tax Rates and Effective Tax Rates) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of the statutory tax rates and the effective tax rates
Statutory rate	21.00%	21.00%
Valuation allowance	(27.90%)	(26.00%)
Nondeductible stock compensation		(0.30%)
Other	6.90%	5.30%
Effective tax rate

Income Taxes (Reconciliation _2

Income Taxes (Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Balance at the beginning of the period	$ 1,060	$ 1,060
Additions based on tax positions related to prior year
Additions based on tax positions related to current year
Balance at the end of the period	$ 1,060	$ 1,060

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Employer contributions	$ 0	$ 0

Litigation (Details)

Litigation (Details) - USD ($) $ in Thousands	1 Months Ended
	Jun. 19, 2020	Jun. 30, 2017	Oct. 07, 2020	Jun. 30, 2020
Private Placement [Member]
Amount sought under alledges	$ 4,000
Savant Neglected Diseases, LLC [Member]
Aggregate cost		$ 3,400
Deductible		500
Offset payment due		$ 2,000
Warrants exercised cashless				100,000
Shares issued				54,545
Savant Neglected Diseases, LLC [Member] | Insufficient under warrant [Member]
Shares issued			54,545
Savant Neglected Diseases, LLC [Member] | Breach of contract related to exercise of warrants [Member]
Warrants exercised cashless			100,000

License and Collaboration Agr_2

License and Collaboration Agreements (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	Jul. 19, 2019	May 30, 2019	Sep. 30, 2020	Dec. 31, 2020	Mar. 31, 2021
Mayo Agreement [Member]
Amount paid in license agreement				$ 200
Kite Agreement [Member]
Amount paid in license agreement		$ 8,000
Kite Agreement [Member] | Research And Development Expense [Member]
Amount paid in license agreement			$ 2,000
Zurich Agreement [Member]
Amount paid in license agreement	$ 100
Zurich Agreement [Member] | Research And Development Expense [Member]
Amount paid in license agreement				$ 100
Manufacturing Agreements [Member] | Subsequent Event [Member]
Commitments					$ 48,000

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2018	Nov. 12, 2019	Jun. 28, 2019	Sep. 19, 2018
Proceeds from advance notes	$ 900
Convertible Promissory Note [Member] | Black Horse Capital LP [Member]
Debt instrument amount				$ 2,500
Issued three short-term, secured bridge notes [Member]
Short term debt			$ 1,700
Issued two short-term, secured bridge notes [Member]
Short term debt		$ 350

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - USD ($) $ in Thousands	2 Months Ended
	Mar. 05, 2021	Mar. 10, 2021
Subsequent Event [Line Items]
Number of share sale in transaction	1,796,858
Sale in transaction	$ 36,200
Term loan, borrowing capacity		$ 80,000
Term loan, initial draw		25,000
Term loan, remaining amount available		$ 55,000