Athersys, Inc / New (ATHXQ) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-33876
Entity Registrant Name	ATHERSYS, INC / NEW
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-4864095
Entity Address, Address Line One	3201 Carnegie Avenue,
Entity Address, City or Town	Cleveland,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44115-2634
City Area Code	216
Local Phone Number	431-9900
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	ATHX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		222,086,507
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001368148
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 64,223	$ 51,546
Prepaid expenses and other	2,998	2,926
Total current assets	67,310	54,561
Property and equipment, net	3,025	3,155
Deposits and other	1,971	1,998
Total assets	72,306	59,714
Current liabilities:
Accrued compensation and related benefits	1,799	1,779
Accrued clinical trial related costs	6,189	6,870
Accrued expenses and other	1,044	1,198
Total current liabilities	27,969	22,954
Other long-term liabilities	455	197
Stockholders’ equity:
Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued and outstanding at March 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value; 300,000,000 shares authorized, and 217,611,507 and 201,973,582 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	218	202
Additional paid-in capital	561,320	527,549
Accumulated deficit	(522,857)	(496,389)
Total stockholders’ equity	38,681	31,362
Total liabilities and stockholders’ equity	72,306	59,714
Consolidated entity excluding, related party
Current liabilities:
Accounts payable	17,167	11,337
Healios
Current assets:
Accounts receivable from Healios	89	89
Current liabilities:
Accounts payable	1,705	1,705
Deferred revenue - Healios	65	65
Advance from Healios	$ 5,201	$ 5,201

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders’ equity:
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	217,611,507	201,973,582
Common stock, shares outstanding (in shares)	217,611,507	201,973,582

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Revenues	$ 0	$ 0
Costs and expenses
Research and development	17,508	12,095
General and administrative	8,837	3,474
Depreciation	244	190
Total costs and expenses	26,589	15,759
Loss from operations	(26,589)	(15,759)
Other income, net	121	115
Net loss and comprehensive loss	$ (26,468)	$ (15,644)
Net loss per share, basic and diluted (in dollars per share)	$ (0.13)	$ (0.10)
Weighted average shares outstanding, basic and diluted (in shares)	208,192	162,715

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Stock Subscription Receivable	Additional Paid-in Capital	Accumulated Deficit	Healios	HealiosCommon Stock	HealiosStock Subscription Receivable	HealiosAdditional Paid-in Capital
Preferred stock shares, beginning balance (in shares) at Dec. 31, 2019		0
Beginning balance at Dec. 31, 2019	$ 23,271	$ 0	$ 160	$ 0	$ 440,735	$ (417,624)
Common stock, beginning balance (in shares) at Dec. 31, 2019			159,791,585
Stock-based compensation	1,280				1,280
Stock subscription receivable from Healios warrant exercise (in shares)								4,000,000
Stock subscription receivable from Healios warrant exercise							$ 0	$ 4	$ (7,040)	$ 7,036
Issuance of common stock (in shares)			6,825,000
Issuance of common stock	10,250		$ 7		10,243
Issuance of common stock under equity compensation plan (in shares)			153,504
Issuance of common stock under equity compensation plan	(149)				(149)
Net comprehensive loss	(15,644)					(15,644)
Preferred stock shares, ending balance (in shares) at Mar. 31, 2020		0
Ending balance at Mar. 31, 2020	$ 19,008	$ 0	$ 171	$ (7,040)	459,145	(433,268)
Common stock, ending balance (in shares) at Mar. 31, 2020			170,770,089
Preferred stock shares, beginning balance (in shares) at Dec. 31, 2020	0	0
Beginning balance at Dec. 31, 2020	$ 31,362	$ 0	$ 202		527,549	(496,389)
Common stock, beginning balance (in shares) at Dec. 31, 2020	201,973,582		201,973,582
Stock-based compensation	$ 3,903				3,903
Issuance of common stock (in shares)			15,200,000
Issuance of common stock	30,495		$ 15		30,480
Issuance of common stock under equity compensation plan (in shares)			437,925
Issuance of common stock under equity compensation plan	(611)		$ 1		(612)
Net comprehensive loss	$ (26,468)					(26,468)
Preferred stock shares, ending balance (in shares) at Mar. 31, 2021	0	0
Ending balance at Mar. 31, 2021	$ 38,681	$ 0	$ 218		$ 561,320	$ (522,857)
Common stock, ending balance (in shares) at Mar. 31, 2021	217,611,507		217,611,507

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities
Net loss	$ (26,468)	$ (15,644)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	244	190
Stock-based compensation	3,903	1,280
Changes in operating assets and liabilities:
Accounts receivable from Healios	0	686
Prepaid expenses, deposits and other	(45)	(279)
Accounts payable, accrued expenses and other	5,273	1,664
Net cash used in operating activities	(17,093)	(12,103)
Investing activities
Purchases of equipment	(114)	(347)
Net cash used in investing activities	(114)	(347)
Financing activities
Proceeds from issuance of common stock	30,506	10,250
Shares retained for withholding tax payments on stock-based awards	(622)	(149)
Net cash provided by financing activities	29,884	10,101
Increase (decrease) in cash and cash equivalents	12,677	(2,349)
Cash and cash equivalents at beginning of the period	51,546	35,041
Cash and cash equivalents at end of the period	$ 64,223	$ 32,692

Background and Basis of Present

Background and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Background and Basis of Presentation Background: Athersys, Inc., including its consolidated subsidiaries (collectively, “we,” “us,” “our,” “Athersys,” and “Company”), is a biotechnology company focused in the field of regenerative medicine and operates in one business segment. Our operations consist of research, clinical development activities, manufacturing and manufacturing process development activities, and our most advanced program is in a pivotal Phase 3 clinical trial. We have incurred losses since our inception in 1995 and had an accumulated deficit of $522.9 million at March 31, 2021, and we will not commence sales of our clinical product candidates until they receive regulatory approval for commercialization. We will require significant additional capital to continue our research and development programs, including progressing our clinical product candidates to potential commercialization and preparing for commercial-scale manufacturing and sales. At March 31, 2021, we had available cash and cash equivalents of $64.2 million. We believe that available proceeds from our existing equity facility, our ability to defer certain spending, and potential deferrals and delays in certain non-core programs, will enable us to meet our obligations as they come due at least for a period of twelve months from the date of the issuance of these unaudited condensed consolidated financial statements. Importantly, we are approaching near-term milestones and clinical trial results, including the results of two clinical trials of our collaborator in Japan, HEALIOS K.K. (“Healios”), followed by the results of our pivotal Phase 3 clinical trial of MultiStem cell therapy for the treatment of ischemic stroke, or MASTERS-2, which we would expect to have a significant impact, favorable or unfavorable, on our ability to access capital from potential third-party commercial partners or the equity capital markets. Depending on the outcome of these clinical trials, we may accelerate, defer or stage the timing of certain programs. In the longer term, we will have to continue to generate additional capital to meet our needs until we would become cash flow positive as a result of the sales of our clinical products, if they are approved for marketing. Such capital would come from new and existing collaborations and their related license fees, milestones and potential royalties, the sale of equity securities from time to time including through our equity facility and grant-funding opportunities. Healios Cooperation Agreement On February 16, 2021, the Company, Healios and Dr. Hardy TS Kagimoto, the Chairman and Chief Executive Officer of Healios and a member of the Company’s board of directors (the “Board”), entered into a cooperation agreement (the “Cooperation Agreement”). The Cooperation Agreement provides for the parties' cooperation on certain commercial matters, including a commitment to work in good faith to finalize negotiations on all aspects of their supply, manufacturing, information provision and regulatory support relationship. Additionally, pursuant to the Cooperation Agreement, the parties agreed to seek to resolve issues over disputed payment obligations for certain manufacturing activities. We presently remain in dispute with Healios on some of these matters. A resolution of these matters may result in changes to our existing collaboration and licensing agreements with Healios. Despite our entry into the Cooperation Agreement, there can be no assurance that we will be able to resolve our disputes. If we are unable to resolve these matters, there could be an adverse impact to our commercialization and development plans and business. The Cooperation Agreement also provides for, among related matters, the dismissal with prejudice of the complaint filed by Dr. Kagimoto against the Company seeking the inspection of the Company's books and records in the Court of Chancery of Delaware on November 21, 2020 (the “Section 220 Litigation”). Pursuant to the Cooperation Agreement, the Company reimbursed Healios and Dr. Kagimoto for reasonable out-of-pocket fees and expenses including legal expenses incurred in connection with the Section 220 Litigation, which were not to exceed $0.5 million in aggregate. A liability in the amount of $0.5 million was recorded in accounts payable to Healios on the condensed consolidated balance sheets at March 31, 2021 and December 31, 2020 and such amount was paid in April 2021. Chief Executive Officer Separation Letter Agreement Effective February 15, 2021, Dr. Gil Van Bokkelen resigned from his position as the Company’s Chief Executive Officer and Chairman of the Board. In connection with his resignation, the Company and Dr. Van Bokkelen entered into a separation letter agreement (the “Separation Letter”) entitling him to severance payments and benefits with an aggregate value of approximately $1.0 million payable in installments over an 18-month period, and providing for a total lump sum payment of approximately $0.2 million. At March 31, 2021, we recorded a liability in the amount of $0.9 million which represents the remaining installments payable to Dr. Van Bokkelen. The lump sum payment was made to Dr. Van Bokkelen in March 2021. The related expense is recorded in general and administrative expense on the unaudited condensed consolidated statement of operations and comprehensive loss. The terms of the Separation Letter also provide for the accelerated vesting of Dr. Van Bokkelen’s outstanding restricted stock units (“RSUs”) and the modification of his stock option awards by providing for accelerated vesting of his unvested stock options and the extension of time during which certain vested stock options can be exercised. In the first quarter of 2021, following the evaluation of the modification, we recorded stock compensation expense of approximately $1.4 million related to the accelerated vesting of Dr. Van Bokkelen’s stock options and $0.9 million related to the accelerated vesting of his RSUs. Lease Agreement On January 4, 2021, we entered into an agreement to lease approximately 214,000 square feet of warehouse and office space. The initial lease term is approximately ten years and includes five renewal options with terms of five years each. Base annual rent for the first year is approximately $1.3 million with 2.0% annual rent escalators. We expect to take possession of the building in the second quarter of 2021. We recorded no rent expense related to the lease during the first quarter of 2021. Retention Program In the first quarter of 2021, we entered into retention letter agreements (“Retention Agreements”) with our executive officers and certain other employees in leadership positions. Each Retention Agreement provides for, among other things, a cash retention bonus and a stock option award, each with vesting tied to continued employment. The cash retention bonuses generally represent a percentage of the employee’s annual compensation and generally vest in full if employed on May 1, 2022. The stock option awards generally vest one-third on May 1, 2022 with the remainder vesting on May 1, 2023, and include a provision for accelerated vesting upon termination without cause. The total cash retention bonus expected to be paid is approximately $2.0 million, which is being expensed over the vesting period. The total stock compensation expense related to the stock option awards is approximately $2.9 million and is being expensed over the vesting period. In April 2021, we expanded the retention program to all remaining employees of the Company, providing for a cash retention bonus with vesting also tied to continued employment through May 1, 2022. The total cash retention bonus expected to be paid on May 1, 2022 for these additional employees is approximately $0.6 million. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2020. The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and Regulation S-X. Accordingly, since they are interim statements, the accompanying financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying financial statements reflect all adjustments, consisting of normal recurring adjustments and disclosures that are, in the opinion of management, necessary for a fair presentation of financial position and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year. Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Our critical accounting policies, estimates and assumptions are described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” which is included in this Quarterly Report on Form 10-Q.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes , which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The ASU is effective for fiscal years beginning after December 15, 2020. We adopted this ASU prospectively on January 1, 2021, and the adoption of the ASU did not have a material impact on our condensed consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) . This ASU replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Subsequent to issuing ASU 2016-13, the FASB issued ASU 2019-10, Financial Instruments - Credit Losses (Topic 326): Effective Dates , delaying the effective date for smaller reporting companies until January 2023. We are currently evaluating the potential impact of adoption of this standard on our consolidated financial statements and disclosures, and we do not intend to early adopt.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share Basic and diluted net loss per share have been computed using the weighted-average number of shares of common stock outstanding during the period. We have outstanding stock-based awards that are not used in the calculation of diluted net loss per share because to do so would be anti-dilutive. Stock-based awards of approximately 21,788,078 and 16,662,000 for the three-months ended March 31, 2021 and 2020, respectively, were excluded from the calculation of diluted net loss per share because their effects would be antidilutive.

Collaborative Arrangements and

Collaborative Arrangements and Revenue Recognition	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements and Revenue Recognition	Collaborative Arrangements and Revenue Recognition Healios Collaboration We have a licensing collaboration with Healios to primarily develop and commercialize our cell therapy technologies for certain disease indications in Japan, pursuant to which we received nonrefundable license fee payments and are entitled to royalties on net sales. We also have the right to receive development and commercial milestone payments from Healios, subject to certain potential credits that have been negotiated from time-to-time and are associated with modifications to the arrangement. Healios is responsible for the development and commercialization of the licensed products in the licensed territories, and we provide certain services to Healios for which we are paid. Refer to Note 6 regarding Healios’ exercise of a warrant in March 2020 and its exercise of a right to participate in certain equity transactions in May 2020. Healios Revenue Recognition At the inception of the Healios arrangement and again each time that the arrangement is modified, all material performance obligations are identified, which currently include (i) licenses to our technology, (ii) product supply services and (iii) services to transfer technology to a contract manufacturer on Healios’ behalf. It was determined that these performance obligations are separate and distinct within the context of the contract. We determine the standalone selling price of each performance obligation and the related transaction price, taking into account variable consideration using the expected value or most likely amount method and reassessing our estimates each reporting period. We constrain, or reduce, the estimates of variable consideration if it is probable that a significant reversal of previously recognized revenue could occur throughout the life of the contract, and both the likelihood and magnitude of a potential reversal of revenue are taken into consideration. At inception and upon each modification date, once the estimated transaction price is established, amounts are allocated to each separate performance obligation on a relative standalone selling price basis. These performance obligations include any remaining, undelivered elements at the time of modifications and any new elements from a modification to the arrangement if the conditions are not met for being treated as a separate agreement. The remaining transaction price for the performance obligations that were not yet delivered is not significant at March 31, 2021. At March 31, 2021, the contract liability, included in Deferred revenue - Healios on the unaudited condensed consolidated balance sheet, is classified as a current liability since the rights to consideration are expected to be satisfied, in all material respects, within one year. Advance from Healios Certain clinical product supply services that were concluded in 2019 involved a cost-sharing arrangement, the proceeds from which may either (i) result in a reduction in the proceeds we receive from Healios upon the achievement of two potential milestones and an increase to a commercial milestone under the license agreement for stroke or (ii) be repaid to Healios at our election, as defined. The cost-sharing proceeds received are recognized in Advance from Healios on the unaudited condensed consolidated balance sheets until the earlier of the milestones being achieved or such amounts being repaid to Healios at our election, at which time, the culmination of the earnings process or the repayment will be complete.

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-based Compensation	Stock-based CompensationOur 2019 Equity and Incentive Compensation Plan (the “EICP”) authorized at inception an aggregate of approximately 18,500,000 shares of common stock for awards to employees, directors and consultants. The EICP authorizes the issuance of stock-based compensation in the form of stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares and units, and other stock-based awards. Under the EICP, in the three-month period ended March 31, 2021, we granted 2,334,192 stock options.As of March 31, 2021, a total of 7,008,612 shares were available for issuance under our EICP, and stock-based awards to purchase 20,788,078 shares of common stock were outstanding under our current and former equity incentive plans, and inducement awards granted outside of our equity incentive plans to purchase 1,000,000 shares of common stock were outstanding. For the three-month periods ended March 31, 2021 and 2020, stock-based compensation expense was approximately $3.9 million and $1.3 million, respectively. At March 31, 2021, total unrecognized estimated compensation cost related to unvested stock-based awards was approximately $13.0 million, which is expected to be recognized by the end of 2025 using the straight-line method.In June 2020, we modified stock option awards granted under the EICP and our prior equity plans for all then-current employees and directors by providing an extension to the period of time during which vested stock options can be exercised, first, for employees, following an employee’s voluntary termination of employment or the involuntary termination of the employee’s employment by the Company without cause (as defined with respect to the applicable options) and second, for directors, following a director’s death or voluntary termination of service with the Company, in each case following significant tenure with the Company. Upon modification, employees have post-employment exercise periods from three months up to a maximum of three years and directors have from eighteen months up to thirty months maximum, with the exercise periods increasing based on the applicable individual’s tenure. The modification was applied to all nonqualified stock option awards outstanding on the modification date and to those incentive stock options held by individuals who accepted the modification. Stock option awards issued post-modification include the extended exercise provisions as described in this paragraph. Following evaluation of the modification of the stock option awards, we recorded stock compensation expense of $1.2 million in the second quarter of 2020 for the incremental value of stock option awards vested prior to the modification date. The remaining incremental value of $0.5 million determined at the modification date, associated with the unvested stock option awards, is being recognized over the remaining vesting period of these modified stock option awards.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Equity Purchase Agreement We have had equity purchase agreements in place since 2011 with Aspire Capital Fund LLC (“Aspire Capital”) that provide us the ability to sell shares to Aspire Capital from time to time. Currently, we have an agreement with Aspire Capital that was entered into in November 2019 (the “2019 Equity Facility”) and includes Aspire Capital’s commitment to purchase up to an aggregate of $100.0 million of shares of our common stock over a defined timeframe. The terms of the 2019 Equity Facility are similar to the previous equity facilities with Aspire Capital, and we issued 350,000 shares of our common stock to Aspire Capital as a commitment fee in November 2019 and filed a registration statement for the resale of 31,000,000 shares of common stock in connection with the equity facility. We sold 15,200,000 shares to Aspire Capital at an average price of $2.01 per share in the first quarter of 2021, generating proceeds of $30.5 million, and we sold 6,825,000 shares to Aspire Capital at an average price of $1.50 per share in the first quarter of 2020, generating proceeds of $10.2 million. Public Offering In April 2020, we completed an underwritten public offering of common stock, generating gross proceeds of approximately $57.6 million and net proceeds of approximately $53.7 million through the issuance of 25,587,500 shares of common stock at an offering price of $2.25 per share. Healios Warrant In March 2020, Healios elected to exercise its warrant in full, and we issued 4,000,000 shares of our common stock at an exercise price equal to the reference price of $1.76 per share, as defined in the warrant. Proceeds of approximately $7.0 million were received in April 2020 in accordance with the terms of the warrant. Healios Investor Rights Agreement

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesWe have United States (“U.S.”) federal net operating loss and research and development tax credit carryforwards, as well as state and city net operating loss carryforwards, which may be used to reduce future taxable income and tax liabilities. We also have foreign net operating loss and tax credit carryforwards, and the foreign net operating loss carryforwards do not expire. All of our deferred tax assets have been fully offset by a valuation allowance due to our cumulative losses. The carrying value of our deferred tax assets and liabilities is determined by the enacted U.S. corporate income tax rate. Consequently, any changes in the U.S. corporate income tax rate impacts the carrying value of our deferred tax assets and liabilities. Also, there are significant limitations on our ability to utilize our net operating loss and tax credit carryforwards under Section 382 of the Internal Revenue Code of 1986, as amended.

Recently Issued Accounting St_2

Recently Issued Accounting Standards (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2020. The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and Regulation S-X. Accordingly, since they are interim statements, the accompanying financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying financial statements reflect all adjustments, consisting of normal recurring adjustments and disclosures that are, in the opinion of management, necessary for a fair presentation of financial position and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year.
Use of Estimates	Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Our critical accounting policies, estimates and assumptions are described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” which is included in this Quarterly Report on Form 10-Q.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes , which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The ASU is effective for fiscal years beginning after December 15, 2020. We adopted this ASU prospectively on January 1, 2021, and the adoption of the ASU did not have a material impact on our condensed consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) . This ASU replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Subsequent to issuing ASU 2016-13, the FASB issued ASU 2019-10, Financial Instruments - Credit Losses (Topic 326): Effective Dates , delaying the effective date for smaller reporting companies until January 2023. We are currently evaluating the potential impact of adoption of this standard on our consolidated financial statements and disclosures, and we do not intend to early adopt.

Background and Basis of Prese_2

Background and Basis of Presentation - Additional Information (Details) $ in Thousands	Feb. 16, 2021USD ($)	Feb. 15, 2021USD ($)	Jan. 04, 2021USD ($)renewalOptionft²	Apr. 30, 2020USD ($)	Mar. 31, 2021USD ($)segment	Mar. 31, 2020USD ($)	Apr. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments | segment					1
Accumulated deficit					$ 522,857			$ 496,389
Cash and cash equivalents					64,223			51,546
Class of Stock [Line Items]
Stock-based compensation expense					3,900	$ 1,300
Unrecognized compensation cost of unvested stock awards					13,000
Deferred Bonus
Class of Stock [Line Items]
Cash retention bonus					2,000
Unrecognized compensation cost of unvested stock awards					$ 2,900
Deferred Bonus | Tranche One
Class of Stock [Line Items]
Vesting percentage					33.33%
Deferred Bonus | Tranche Two
Class of Stock [Line Items]
Vesting percentage					66.67%
Building
Class of Stock [Line Items]
Number of square feet leased | ft²			214,000
Lease term (in years)			10 years
Number of renewal options | renewalOption			5
Renewal term (in years)			5 years
Payment due for base annual rent in first year			$ 1,300
Retention stock option award vesting rights (as a percent)			2.00%
Former Chief Executive Officer
Class of Stock [Line Items]
Severance payments and benefits		$ 1,000
Severance payments and benefits, period (in months)		18 months
Lump sum payment		$ 200			$ 900
Former Chief Executive Officer | Stock Options
Class of Stock [Line Items]
Stock-based compensation expense					1,400
Former Chief Executive Officer | RSUs
Class of Stock [Line Items]
Stock-based compensation expense					900
Additional Employees | Deferred Bonus | Subsequent Event
Class of Stock [Line Items]
Deferred compensation, cash award granted							$ 600
Section 220 Litigation | Maximum | Pending Litigation
Class of Stock [Line Items]
Fees and expenses sought by plaintiff	$ 500
Accounts payable, related parties, current					$ 500			$ 500
Healios
Class of Stock [Line Items]
Proceeds from exercise of warrants				$ 7,000
Public Stock Offering
Class of Stock [Line Items]
Net proceeds from public offering				$ 53,700

Net Loss per Share (Details)

Net Loss per Share (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share Based Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock-based awards	21,788,078	16,662,000

Collaborative Arrangements an_2

Collaborative Arrangements and Revenue Recognition - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019milestone
Regulatory and sales milestones | Healios
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of future milestones achieved	2

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for equity incentive plan (in shares)		18,500,000
Stock options granted (in shares)		2,334,192
Shares available for issuance (in shares)		7,008,612
Stock-based compensation expense		$ 3.9		$ 1.3
Unrecognized compensation cost of unvested stock awards		$ 13
2019 Equity And Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock outstanding (in shares)		20,788,078
2019 Equity And Incentive Compensation Plan | Employees | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Post-employment exercise period (in years and months)	3 months
2019 Equity And Incentive Compensation Plan | Employees | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Post-employment exercise period (in years and months)	3 years
2019 Equity And Incentive Compensation Plan | Directors | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Post-employment exercise period (in years and months)	18 months
2019 Equity And Incentive Compensation Plan | Directors | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Post-employment exercise period (in years and months)	30 months
Inducement Awards Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock outstanding (in shares)		1,000,000
2019 Equity And Incentive Compensation Plan, Modification
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 1.2
Unrecognized compensation cost of unvested stock awards	$ 0.5		$ 0.5

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended
	May 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Nov. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Net proceeds from sales of common stock					$ 30,506	$ 10,250
Public Stock Offering
Class of Stock [Line Items]
Gross proceeds from public offering		$ 57,600
Consideration received from sale of stock		$ 53,700
Shares issued and sold (in shares)		25,587,500
Offering price (in dollars per share)		$ 2.25
Common Stock
Class of Stock [Line Items]
Issuance of common stock, new issues (in shares)					15,200,000	6,825,000
Aspire Capital
Class of Stock [Line Items]
Equity purchase agreement, value				$ 100,000
Common stock issued as commitment fees (in shares)				350,000
Common stock registered for resale (in shares)				31,000,000
Net proceeds from sales of common stock					$ 30,500	$ 10,200
Aspire Capital | Common Stock
Class of Stock [Line Items]
Issuance of common stock, new issues (in shares)					15,200,000	6,825,000
Sale of additional shares at an average price (in dollars per share)					$ 2.01	$ 1.50
Healios
Class of Stock [Line Items]
Common stock issued upon exercise of warrant (in shares)			4,000,000
Common stock issued, price per share (in dollars per share)			$ 1.76
Proceeds from exercise of warrants		$ 7,000
Healios | Securities Purchase Agreement
Class of Stock [Line Items]
Consideration received from sale of stock	$ 500
Shares issued and sold (in shares)	310,526
Offering price (in dollars per share)	$ 1.72