Athersys, Inc / New (ATHXQ) 10-Q 15 May 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	May 11, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-33876
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		20,870,888
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Entity Registrant Name	ATHERSYS, INC / NEW
Entity Central Index Key	0001368148
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 3,121	$ 9,038
Prepaid clinical trial costs	2,747	2,747
Prepaid expenses and other	1,252	1,034
Total current assets	7,836	13,535
Operating right-of-use assets, net	7,591	7,846
Property and equipment, net	4,079	4,214
Deposits and other	2,126	2,136
Total assets	21,632	27,731
Current liabilities:
Accounts payable	28,959	27,765
Operating lease liabilities, current	675	746
Accrued compensation and related benefits	654	1,090
Accrued clinical trial related costs	7,258	7,231
Accrued expenses and other	974	1,078
Warrant liability	1,163	534
Total current liabilities	39,683	38,444
Operating lease liabilities, non-current	7,762	7,939
Stockholders’ equity:
Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued and outstanding at March 31, 2023 and December 31, 2022	0	0
Common stock, $0.001 par value; 600,000,000 shares authorized with 18,448,489 and 17,986,147 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	18	18
Additional paid-in capital	632,660	632,009
Accumulated deficit	(663,689)	(655,878)
Total stockholders’ equity (deficit)	(31,011)	(23,851)
Total liabilities and stockholders’ equity	21,633	27,731
Healios
Current assets:
Accounts receivable from Healios	716	716
Current liabilities:
Advance from Healios	$ 5,199	$ 5,199

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
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)	600,000,000	600,000,000
Common stock, shares issued (in shares)	18,448,489	17,986,147
Common stock, shares outstanding (in shares)	18,448,489	17,986,147

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues
Contract revenue from Healios	$ 0	$ 2,912
Total revenues	0	2,912
Costs and expenses
Research and development	4,467	20,944
General and administrative	2,815	4,099
Depreciation	52	247
Total costs and expenses	7,334	25,290
Loss from operations	(7,334)	(22,378)
Other income, net	(477)	162
Net loss	(7,811)	(22,216)
Comprehensive loss	$ (7,811)	$ (22,216)
Net loss per share, basic (in dollars per share)	$ (0.43)	$ (2.27)
Net loss per share, diluted (in dollars per share)	$ (0.43)	$ (2.27)
Weighted average shares outstanding, basic (in shares)	18,292	9,768
Weighted average shares outstanding, diluted (in shares)	18,292	9,768

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands		Total	Preferred Stock	Common Stock		Additional Paid-in Capital	Accumulated Deficit
Preferred stock shares, beginning balance (in shares) at Dec. 31, 2021			0
Beginning balance at Dec. 31, 2021		$ 16,369	$ 0	$ 10		$ 599,703	$ (583,344)
Common stock, beginning balance (in shares) at Dec. 31, 2021	[1]			9,713,767
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		1,410				1,410
Issuance of common stock (in shares)	[1]			129,333
Issuance of common stock		4,803				4,803
Issuance of common stock under equity compensation plan (in shares)	[1]			148,611
Issuance of common stock under equity compensation plan		(58)				(58)
Net loss		(22,216)					(22,216)
Net and comprehensive loss		(22,216)					(22,216)
Preferred stock shares, ending balance (in shares) at Mar. 31, 2022			0
Ending balance at Mar. 31, 2022		$ 307	$ 0	$ 10		605,857	(605,560)
Common stock, ending balance (in shares) at Mar. 31, 2022	[1]			9,991,711
Preferred stock shares, beginning balance (in shares) at Dec. 31, 2022		0	0
Beginning balance at Dec. 31, 2022		$ (23,851)	$ 0	$ 18		632,009	(655,878)
Common stock, beginning balance (in shares) at Dec. 31, 2022		17,986,147		17,986,147	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		$ 707				707
Stock Issue- warrant exercise (in shares)	[1]			344,170
Issuance of common stock under equity compensation plan (in shares)	[1]			118,172
Issuance of common stock under equity compensation plan		(56)				(56)
Net loss		(7,811)					(7,811)
Net and comprehensive loss		$ (7,811)					(7,811)
Preferred stock shares, ending balance (in shares) at Mar. 31, 2023		0	0
Ending balance at Mar. 31, 2023		$ (31,011)	$ 0	$ 18		$ 632,660	$ (663,689)
Common stock, ending balance (in shares) at Mar. 31, 2023		18,448,489		18,448,489	[1]
[1]Reflects the 1-for-25 reverse stock split that became effective August 26, 2022. Refer to Note 1, “Background and Basis of Presentation.”

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders’ Equity (Parenthetical)	Aug. 26, 2022
Statement of Stockholders' Equity [Abstract]
Reverse stock split, conversion ratio	0.04

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net loss	$ (7,811)	$ (22,216)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	52	247
Stock-based compensation	707	1,410
Changes in operating assets and liabilities:
Accounts receivable from Healios - billed and unbilled	0	(229)
Prepaid expenses, deposits and other	22	(217)
Accounts payable, accrued expenses and other	435	1,975
Deferred revenue - Healios	0	(1,138)
Net cash used in operating activities	(5,966)	(20,168)
Investing activities
Proceeds from the sale of equipment	105	0
Purchases of equipment	0	(186)
Net cash provided (used) in investing activities	105	(186)
Financing activities
Proceeds from issuance of common stock, net of issuance cost	0	4,802
Shares retained for withholding tax payments on stock-based awards	(56)	(58)
Net cash (used) provided by financing activities	(56)	4,744
Decrease in cash and cash equivalents	(5,917)	(15,610)
Cash and cash equivalents at beginning of the period	9,038	37,407
Cash and cash equivalents at end of the period	3,121	21,797
Change in fair value of warrant liabilities	$ 629	$ 0

Background and Basis of Present

Background and Basis of Presentation	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Background and Basis of Presentation Organization Athersys, Inc., including its consolidated subsidiaries (collectively, “we,” “us,” “our,” “Athersys,” and the “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 for the treatment of ischemic stroke. 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, 2022. 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. 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. Reverse stock split On August 26, 2022, the Company amended its Certificate of Incorporation to implement a 1-for-25 reverse stock split of its common stock. The reverse stock split did not cause an adjustment to the par value or the authorized shares of the common stock. As a result of the reverse stock split, the Company adjusted the share amounts under its employee equity incentive plans, inducement awards and common stock warrant agreements with third parties. All disclosures of common shares and per common share data in the accompanying interim financial statements and related notes reflect the reverse stock split for all periods presented.

Going Concern

Going Concern	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Going Concern	Going Concern We have prepared our unaudited condensed consolidated financial statements on a going concern basis, which assumes that we will realize our assets and satisfy our liabilities in the normal course of business. However, we have incurred net losses since our inception in 1995 and have negative operating cash flows. These factors, among others, raise substantial doubt about our ability to continue as a going concern within one year after the date that these financial statements are issued. The accompanying unaudited condensed consolidated financial statements do not include any adjustments to reflect the possible future effect on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of the uncertainty concerning our ability to continue as a going concern.

Accounting Standards Adopted

Accounting Standards Adopted	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Accounting Standards Adopted	Accounting Standards Adopted 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. The impact of adoption of this standard did not have a material impact on the consolidated financial statements and disclosures.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2023
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 our common stock outstanding during the period. As of March 31, 2023, we have outstanding options, restricted stock units and warrants that were not used in the calculation of diluted net loss per share because to do so would be antidilutive. As of March 31, 2023, we had warrants outstanding to purchase an aggregate of 400,000 shares of our common stock that were issued to HEALIOS K.K. (“Healios”) in August 2021 and are not yet exercisable according to their terms. Additionally, as of March 31, 2023, we had outstanding warrants to purchase 1,920,000, 2,000,000, and 9,109,090 shares of our common stock that were issued in August 2022, September 2022, and November 2022, respectively. Refer to Note 8 for additional information. The following instruments were excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive. Three months ended 2023 2022 Stock options 1,196,530 1,307,832 Restricted stock units 859,282 66,258 Warrants - refer to Note 8 13,429,090 400,000 Total 15,484,902 1,774,090

Property and Equipment, net

Property and Equipment, net	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net For the periods ended Property and equipment consists of (in thousands): March 31, December 31, Laboratory equipment 7,244 $ 7,576 Office equipment and leasehold improvements 3,934 3,934 Equipment and leasehold improvements not yet in service 2,313 2,313 13,491 13,823 Accumulated depreciation and amortization (9,412) (9,609) $ 4,079 $ 4,214 (9,412) Long-lived assets are evaluated for impairment when events or changes in circumstances indicate that the carrying amount of the asset or related group of assets may not be recoverable. In June 2022, we announced a restructuring plan (the “Plan”) of our organization with the intention of significantly reducing expenses, conserving cash, improving the focus of the Company’s activities and becoming more attractive to potential financial and strategic partners. The Plan included a significant reduction in our workforce and changes to our management team. The Plan also includes the reduction of our internal research function, the decommissioning of certain equipment and pausing our manufacturing and process development efforts toward commercializing our MultiStem product candidate. As a result of these actions, during 2022, we recorded impairment charges of approximately $7.2 million to adjust the carrying amount of certain equipment assets to the estimated market value of similar assets, we have not recorded any additional impairment during the period ending March 31, 2023. The impairment charges were included in research and development costs and expenses on the condensed consolidated statements of operations and comprehensive loss starting in June 2022.

Collaborative Arrangements and

Collaborative Arrangements and Revenue Recognition	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements and Revenue Recognition	Collaborative Arrangements and Revenue Recognition Healios Collaboration We have a licensing agreement 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 territory, and we provide certain services to Healios for which we are paid. In August 2021, the Company and Healios entered into a Comprehensive Framework Agreement for Commercial Manufacturing and Ongoing Support, or the Framework Agreement, which provided for clarification under and modified the existing agreements between the parties. It also provided Healios with deferral of certain milestone payments. Under the Framework Agreement, the Company was entitled to payments for reimbursable services of which $0.7 million and $1.6 million are included in accounts receivable from Healios at March 31, 2023 and March 31, 2022, respectively. In addition, under the Framework Agreement, the Company was entitled to a $3.0 million milestone payment from Healios and was obligated to pay Healios $1.1 million by December 31, 2022. In September 2022, we received $1.9 million from Healios, which represents the milestone payment net of amounts owed to Healios. Additionally, to assist Healios with the advancement of its ischemic stroke and acute respiratory distress syndrome (“ARDS”) programs in Japan, in September 2022, we granted to Healios, subject to the terms of the licensing agreement, a non-exclusive license to make and have made MultiStem for the treatment of ischemic stroke and ARDS worldwide solely for import for use in Japan. In connection with the execution of the Framework Agreement, the Cooperation Agreement was amended to extend certain customary standstill provisions until the conclusion of our 2023 annual meeting of stockholders. In August 2021, we also issued two warrants (together, the “2021 Warrants”) to Healios in connection with the Framework Agreement to purchase up to a total of 400,000 shares of our common stock. The 2021 Warrants are being accounted for as consideration paid or payable to a customer according to Topic 606, Revenue from Contracts with Customers , and Topic 718, Compensation Stock Compensation , under which the recognition of such equity instruments is required at the time that the underlying performance conditions become probable or are satisfied. As of March 31, 2023, the 2021 Warrants have not been recorded as the underlying performance conditions have not been satisfied and are not yet considered probable. Refer to Note 8 for further information. Healios has alleged that we are in material breach of our Framework Agreement for, among other things, not meeting our supply obligations and cooperation and assistance obligations. We strongly disagree with Healios’ allegations and will continue to work with Healios to try to resolve this dispute. However, there can be no assurance that we will be able to resolve this dispute without legal proceedings. Healios Revenue Recognition At the inception of the Healios arrangement and again each time that the arrangement has been modified, all material performance obligations were identified, which include (i) licenses to our technology, (ii) product supply services, and (iii) manufacturing services provided on Healios’ behalf. Under the Framework Agreement, it was determined there was one performance obligation for services necessary for regulatory approvals, manufacturing readiness, and commercial launch in Japan. We determined the transaction price included estimated payments for reimbursable services to be performed by us for Healios and the $3.0 million milestone payment. We allocated the total transaction price to this one performance obligation. We began recognizing revenue in the third quarter of 2021 as the services were being performed. At March 31, 2023, the services related to this performance obligation are largely complete and consist of minimal close-out activities which are immaterial. During the three months ended March 31, 2023 we recognized no revenue associated with this performance obligation, compared to $2.8 million for three months ended March 31, 2022. We recognized no revenue for three months ended March 31, 2023 and March 31, 2022 from performance obligations satisfied in previous periods. Accounts receivable from Healios Accounts receivable from Healios are related to our contracts and are recorded when the right to consideration is unconditional at the amount that management expects to collect. Accounts receivable from Healios do not bear interest if paid when contractually due, and payments are generally due within thirty Advance from Healios In 2017, we amended the clinical trial supply agreement for the manufacturing of clinical product for TREASURE to clarify a cost-sharing arrangement. The proceeds from Healios that relate specifically to the cost-sharing arrangement 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. Disaggregation of Revenues We recognize product supply revenue at a point in time upon delivery, as defined in the applicable product supply contracts, while service revenue is recognized when earned over time. The following table presents our contract revenues disaggregated by timing of revenue recognition (in thousands): Three months ended Three months ended Point in Over Time Point in Over Time Contract Revenue from Healios Product supply revenue $ — $ — $ — $ — Service revenue — — — 2,912 Total disaggregated revenues $ — $ — $ — $ 2,912

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
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 1,700,000 shares of our 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. As of March 31, 2023, a total of 627,290 shares (including 11,289 shares related to an expired incentive plan) of common stock have been issued under our equity incentive plans.As of March 31, 2023, a total of 27,491 shares were available for issuance under our EICP, and stock-based awards representing 1,626,312 (including 28,404 shares related to an expired incentive plan) of common stock were outstanding. Additionally, inducement stock options granted outside of our equity incentive plans to purchase 429,500 shares of common stock were outstanding at March 31, 2023. For the three months ended March 31, 2023 and 2022, stock-based compensation expense was approximately $0.7 million and $1.4 million, respectively. At March 31, 2023, total unrecognized estimated compensation cost related to unvested stock-based awards was approximately $4.6 million, which is expected to be recognized by the end of 2026 using the straight-line method.

Stockholders_ Equity and Warran

Stockholders’ Equity and Warrants	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Stockholders’ Equity and Warrants	8. Stockholders’ Equity and Warrants At March 31, 2023 and March 31, 2022, we had 600,000,000 shares of common stock and 10,000,000 shares of undesignated preferred stock authorized. No shares of preferred stock have been issued as of March 31, 2023 and 2022. August 2022 Securities Purchase Agreement On August 15, 2022, the Company entered into a placement agency agreement with A.G.P./Alliance Global Partners (“A.G.P.”), pursuant to which A.G.P. agreed to serve as exclusive placement agent for the issuance and sale of common stock and warrants. A.G.P. received a placement fee of approximately $0.8 million and approximately $0.1 million for the reimbursement of expenses. On August 15, 2022, the Company entered into a securities purchase agreement (the “August 2022 Purchase Agreement”) with an investor, pursuant to which the Company agreed to issue and sell, in a registered direct offering, (i) an aggregate of 1,200,000 shares of the Company’s common stock, (ii) pre-funded warrants (the “August 2022 Pre-Funded Warrants”) exercisable for an aggregate of 720,000 shares of common stock and (iii) warrants (the “August 2022 Common Warrants”) exercisable for an aggregate of 1,920,000 shares of common stock, in combinations of one share of common stock or one August 2022 Pre-Funded Warrant and one August 2022 Common Warrant for a combined purchase price of $6.25 (less $0.0025 for any August 2022 Pre-Funded Warrant). Subject to certain ownership limitations, under the terms of the August 2022 Purchase Agreement, the August 2022 Pre-Funded Warrants were exercisable upon issuance, and the August 2022 Common Warrants were exercisable upon the six-month anniversary of issuance for a five-year period. Under the August 2022 Purchase Agreement, each August 2022 Pre-Funded Warrant was exercisable for one share of common stock at a price per share of $0.0025 and each August 2022 Common Warrant was exercisable for one share of common stock at a price per share of $6.385. The offering closed on August 17, 2022 and the Company received net proceeds of approximately $11.0 million, after giving effect to the payment of placement fees and expenses. On August 29, 2022, the August 2022 Pre-Funded Warrants were exercised in full and re-measured to fair value. Upon remeasurement and exercise, we recorded a gain of $0.8 million to adjust the warrant liability associated with the August 2022 Pre-Funded Warrants to fair value and reclassified the $3.8 million warrant liability to additional paid-in capital. The fair value adjustment is recorded in other income, net on the condensed consolidated statement of operations and comprehensive loss. Pursuant to the August 2022 Purchase Agreement, in the event the Company proposes a future offering to sell shares of common stock during the twelve months following the closing date, the investor has the right to participate in each offering in an amount up to 30.0%. On September 22, 2022, the Company entered into an amendment to the Purchase Agreement (the “August 2022 Purchase Agreement Amendment”) with the investor to, among other things, (i) amend the August 2022 Common Warrants to be exercisable for a seven-year period after the six-month anniversary of the closing date, (ii) reduce the standstill period, (iii) reduce the term and the amount of the participation right, and (iv) require the investor, subject to certain conditions, to participate in future offerings to sell certain securities to investors primarily for capital raising purposes. On September 22, 2022, in consideration of the August 2022 Purchase Agreement Amendment, and without receiving any cash proceeds, the Company issued to the investor additional warrants exercisable for 2,000,000 shares of common stock (the “September Warrants”) at a price of $6.385 for a seven-year period after the six-month anniversary of the date of issuance thereof. November 2022 Securities Purchase Agreement On November 9, 2022, the Company entered into a placement agency agreement with A.G.P. pursuant to which A.G.P. agreed to serve as exclusive placement agent for the issuance and sale of common stock and warrants. A.G.P received a placement fee of approximately $0.4 million and approximately $0.1 million for the reimbursement of expenses. On November 9, 2022, the Company entered into a securities purchase agreement (the “November 2022 Purchase Agreement”) with investors, pursuant to which the Company agreed to issue and sell, in a public offering, (i) an aggregate of 3,927,275 shares of the Company’s common stock, (ii) pre-funded warrants (the “November 2022 Pre-Funded Warrants”) exercisable for an aggregate of 1,077,270 shares of common stock and (iii) warrants (the “November 2022 Common Warrants”) exercisable for an aggregate of 10,009,090 shares of common stock, in combinations of one share of common stock or one November 2022 Pre-Funded Warrant and two November 2022 Common Warrants for a combined purchase price of $1.10 (less $0.0001 for any November 2022 Pre-Funded Warrant). Subject to certain ownership limitations, under the terms of the November 2022 Purchase Agreement, the November 2022 Pre-Funded Warrants and November 2022 Common Warrants were exercisable upon issuance. Under the November 2022 Purchase Agreement, each November 2022 Pre-Funded Warrant was exercisable for one share of common stock at a price per share of $0.0001 and each November 2022 Common Warrant is exercisable for one share of common stock at a price per share of $1.10 for a five-year period after the date of issuance. The offering closed on November 10, 2022 and the Company received net proceeds of approximately $5.0 million, after giving effect to the payment of placement fees and expenses. The November 2022 Pre-Funded Warrants were exercised in full at the closing. The Company has assessed the Pre-Funded Warrants, the Common Warrants and the September Warrants (collectively, the “Warrants”) for appropriate equity or liability classification pursuant to the Company’s accounting policy as described in Note C, in our Annual Report on Form 10-K. The Warrants contain a provision pursuant to which the warrant holder has the option to receive cash in the event there is a fundamental transaction (contractually defined to include various merger, acquisition or stock transfer activities). The Warrants meet the definition of a derivative pursuant to ASC 815, Derivatives and Hedging and do not meet the derivative scope exception. As a result, the Warrants were initially recorded as liabilities and measured at fair value using the Black-Scholes valuation model. Issuance costs of $0.5 million were allocated to the Pre-Funded Warrants and Common Warrants and recorded in other income, net on the condensed consolidated statement of operations and comprehensive loss in the three ended September 30, 2022. The remaining issuance costs of $0.4 million were allocated to the Common Stock and recorded in additional paid-in capital. During the three months ended March 31, 2023, the Company recognized a net gain of 0.8 million for the fair value adjustment related to the warrant liabilities. As of March 31, 2023, the fair value of the warrant liabilities was $1.2 million. April 2023 Securities Purchase Agreement On April 18, 2023, the Company entered into a placement agency with A.G.P. pursuant to which A.G.P. agreed to serve as the exclusive placement agent for the issuance and sale of the Shares and Warrants. A.G.P. received a placement fee of approximately $0.2 million and approximately $0.1 million for the reimbursement of expenses. On April 18, 2023, the Company entered into a securities purchase agreement (the “April 2023 Purchase Agreement”) with investors, pursuant to which the Company agreed to issue and sell, in a registered direct offering, (i) an aggregate of 2,315,000 shares of the Company’s common stock and (ii) pre-funded warrants (the “ April 2023 Pre-Funded Warrants”) exercisable for an aggregate of 1,370,000 shares of Common Stock, together with warrants (the “Common Warrants” and, collectively with the April 2023 Pre-Funded Warrants, the “April Common Warrants”) exercisable for an aggregate of 3,685,000 shares of the Company’s common stock in a private placement, in combinations of one share or one April 2023 Pre-Funded Warrant and one April Common Warrant for a combined purchase price of $1.00. Subject to certain ownership limitations, the April 2023 Pre-Funded Warrants are exercisable upon issuance, and the April Common Warrants are exercisable upon the six-month anniversary of issuance. Each April 2023 Pre-Funded Warrant is exercisable for one share of common stock at a price per share of $0.0001 (as adjusted from time to time in accordance with the terms thereof) and does not expire. Each April 2023 Common Warrant is exercisable into one share of common stock at a price per share of $0.96 (as adjusted from time to time in accordance with the terms thereof) for a seven-year period after the six-month anniversary of the date of issuance. The offering closed on April 19, 2023, and received net proceeds of approximately $3.4 million, after giving effect to the payment of placement fees and expenses. Healios 2021 Warrants In August 2021, we issued the 2021 Warrants to Healios to purchase up to an aggregate of 400,000 shares of our common stock. One of the 2021 Warrants is for the purchase of up to 120,000 shares at an exercise price of $45.00 per share, subject to specified increases, and generally is only exercisable within 60 days of receipt of either conditional or full marketing approval from the Pharmaceuticals and Medical Devices Agency in Japan (the “PMDA”) for the intravenous administration of MultiStem to treat patients who are suffering from acute respiratory distress syndrome. The other 2021 Warrant is for the purchase of up to 280,000 shares at an exercise price of $60.0 per share, subject to specified increases, and generally is only exercisable within 60 days of receipt of either conditional or full marketing approval from the PMDA for the intravenous administration of MultiStem to treat patients who are suffering from ischemic stroke. The 2021 Warrants may be terminated by us under certain conditions and have an exercise cap triggered at Healios’ ownership of 19.9% of our common stock. Equity Purchase Agreement We previously had equity purchase agreements in place since 2011 with Aspire Capital that provided us the ability to sell shares to Aspire Capital from time to time. On May 12, 2022, we entered into an agreement (the “2022 Equity Facility”) that included 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 2022 Equity Facility were similar to the previous equity facilities with Aspire Capital. Our prior equity facility that was entered into in June 2021, or the 2021 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 2021 Equity Facility are similar to the previous equity facilities with Aspire Capital, and we filed a registration statement for the resale of 1,600,000 shares of our common stock in connection with the 2021 Equity Facility. Our prior equity facility that was entered into in 2019, that was fully utilized and terminated during the third quarter of 2021. On July 6, 2022, Aspire Capital terminated the 2022 Equity Facility. Aspire Capital had the right to terminate the 2022 Equity Facility at the time or any time after any of the Company’s then current executive officers ceased to be an executive officer or full-time employee of the Company, which right was triggered in connection with the departures of William Lehmann, former president and Chief Operating Officer, John Harrington, Former Executive Vice President and Chief Scientific Officer, and Ivor MacLeod, former Chief Financial Officer. During quarter ended March 31, 2022, we sold 272,000 shares to Aspire Capital at average prices of $17.66 per share.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The carrying amounts of certain financial instruments, including cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their respective fair values due to the short-term nature of such instruments. Liabilities Measured at Fair Value on a Recurring Basis The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period. The requirement requires judgements to be made. Our Level 3 financial liabilities consist of the warrant liabilities for which there is no current market such that the determination of fair value requires judgement or estimation. Changes in fair value measurements categorized within Level 3 of the fair value hierarchy are analyzed each period based on changes in estimates or assumptions and recorded as appropriate. The Company uses the Black-Scholes option valuation model to value the Level 3 warrant liabilities at inception and on subsequent valuation dates. This model incorporates transaction detail such as the Company’s stock price, contractual terms, maturing, risk free rates as well as volatility. The unobservable input for the Level 3 warrant liabilities includes volatility, which is not significant to the fair value measurement of the warrant liabilities. A reconciliation of the beginning and ending balances for the warrant liabilities which are measured at fair value on a recurring basis using significant unobservable inputs (Level 3) is as follows (in thousands): Warrant Liabilities Balance December 31, 2022 $ (534,000) Fair Value Adjustment - March 31, 2023 (629,000) Balance March 31, 2023 $ (1,163,000)

Restructuring Charges

Restructuring Charges	3 Months Ended
	Mar. 31, 2023
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges In June 2022, we announced a restructuring of our organization, including an approximate 70% reduction in our workforce. As part of the Plan we also announced changes to our executive team. Mr. Lehmann left the Company on May 31, 2022. Dr. Harrington and Mr. Macleod left the Company on June 30, 2022. The Company’s restructuring efforts are intended to preserve cash and reduce operating expenses going forward. In addition to the workforce reductions, the Company’s restructuring efforts include the reduction of our internal research function, the decommissioning of certain equipment and pausing our manufacturing and process development efforts toward commercializing our MultiStem product candidate. We are attempting to negotiate payment terms with our primary contract manufacturing organization responsible for the manufacture of Multistem. The following table sets forth certain details associated with the restructuring charges incurred in the three months ended March 31, 2023 and the obligations recorded for the expenses associated with the Plan (in thousands). It is anticipated the Plan will be completed by mid-2023. Balances Cash Balances December 31, 2022 Charges (payments) March 31, 2023 Employee severance and benefits 935 $ — $ (370) $ 565 Legal and professional fees 35 15 (23) 27 Other 15 — — 15 $ 985 $ 15 $ (393) $ 607 The current portion of our restructuring accrual is included in accrued compensation and related benefits and accounts payable and there is no long-term portion of our restructuring accrual. Restructuring charges are recorded general and administrative costs and expenses for the three months ended March 31, 2023.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
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. Substantially 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. The utilization of net operating loss and tax credit carryforward generated prior to October 2012 (the “Section 382 Limited Attributes”) is substantially limited under Section 382 of the Internal Revenue Code of 1986, as amended, (the “IRC”). We generated U.S. federal net operating loss carryforwards of $348.1 million, research and development tax credits of $24.4 million, and state and local net operating loss carryforwards of $140.3 million since 2012. Utilization of some of the federal and state net operating loss and tax credit carryforwards generated after October 2012 may be subject to additional annual limitations due to the “change in ownership” provisions of the IRC and similar state provisions. The annual limitations may result in the expiration of net operating losses and credits before utilization. The Company has not performed a Section 382 study subsequent to October 2012 as of March 31, 2023. We will update our analysis under Section 382 prior to using these attributes.

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On April 13, 2023, we received notice from The Nasdaq Stock Market (“Nasdaq”) that we had not regained compliance with the minimum market value of $35 million. On April 14, 2023, we filed our request for a hearing and our common stock is currently not being delisted pending the outcome of the hearing with Nasdaq Hearing Panel (the “Panel”). There can be no assurance that such appeal will be successful or that the Company will be able to regain compliance with the $35 million minimum market value or maintain compliance with other Nasdaq listing requirements. If the Company’s appeal is denied or if it fails to regain compliance with Nasdaq’s continued listing standards during any period granted by the Panel, the Common Stock will be subject to delisting from Nasdaq. On April 17, 2023, the Company amended the August Warrants and the September Warrants to, among other things, reduce the exercise price to $0.96 per share with respect to 1,920,000 shares of Common Stock covered by the August Warrants and 1,760,000 shares of Common Stock covered by the September Warrants. On April 18, 2023, the Company entered into a placement agency with A.G.P. pursuant to which A.G.P. agreed to serve as the exclusive placement agent for the issuance and sale of the Shares and Warrants. A.G.P. received a placement fee of approximately $0.2 million and approximately $0.1 million for the reimbursement of expenses. On April 18, 2023, the Company entered into a securities purchase agreement (the “April 2023 Purchase Agreement”) with investors, pursuant to which the Company agreed to issue and sell, in a registered direct offering, (i) an aggregate of 2,315,000 shares of the Company’s common stock and (ii) pre-funded warrants (the “ April 2023 Pre-Funded Warrants”) exercisable for an aggregate of 1,370,000 shares of Common Stock, together with warrants (the “Common Warrants” and, collectively with the April 2023 Pre-Funded Warrants, the “April Common Warrants”) exercisable for an aggregate of 3,685,000 shares of the Company’s common stock in a private placement, in combinations of one share or one April 2023 Pre-Funded Warrant and one April Common Warrant for a combined purchase price of $1.00. Subject to certain ownership limitations, the April 2023 Pre-Funded Warrants are exercisable upon issuance, and the April Common Warrants are exercisable upon the six-month anniversary of issuance. Each April 2023 Pre-Funded Warrant is exercisable for one share of common stock at a price per share of $0.0001 (as adjusted from time to time in accordance with the terms thereof) and does not expire. Each April 2023 Common Warrant is exercisable into one share of common stock at a price per share of $0.96 (as adjusted from time to time in accordance with the terms thereof) for a seven-year period after the six-month anniversary of the date of issuance. The offering closed on April 19, 2023, and received net proceeds of approximately $3.4 million, after giving effect to the payment of placement fees and expenses. On April 21, 2023, we made the decision to and notified our landlord for the Stow facility that we surrendered possession of the property and returned the keys to the landlord. As a result of the impact this will have to operating results and cash flows, the Company has determined impairment indicators exist and will report any potential impairment charges within the quarterly report for quarter ending June 30, 2023, for assets including operating right of use assets.

Accounting Standards Adopted (P

Accounting Standards Adopted (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	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, 2022. 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.
Accounting Standards Adopted	Accounting Standards Adopted 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. The impact of adoption of this standard did not have a material impact on the consolidated financial statements and disclosures.

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of Instruments Excluded from Calculation of Diluted Net Loss Per Share	The following instruments were excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive. Three months ended 2023 2022 Stock options 1,196,530 1,307,832 Restricted stock units 859,282 66,258 Warrants - refer to Note 8 13,429,090 400,000 Total 15,484,902 1,774,090

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, net	For the periods ended Property and equipment consists of (in thousands): March 31, December 31, Laboratory equipment 7,244 $ 7,576 Office equipment and leasehold improvements 3,934 3,934 Equipment and leasehold improvements not yet in service 2,313 2,313 13,491 13,823 Accumulated depreciation and amortization (9,412) (9,609) $ 4,079 $ 4,214 (9,412)

Collaborative Arrangements an_2

Collaborative Arrangements and Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Contract Revenues Disaggregated by Timing of Revenue Recognition	The following table presents our contract revenues disaggregated by timing of revenue recognition (in thousands): Three months ended Three months ended Point in Over Time Point in Over Time Contract Revenue from Healios Product supply revenue $ — $ — $ — $ — Service revenue — — — 2,912 Total disaggregated revenues $ — $ — $ — $ 2,912

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Warrant Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs	A reconciliation of the beginning and ending balances for the warrant liabilities which are measured at fair value on a recurring basis using significant unobservable inputs (Level 3) is as follows (in thousands): Warrant Liabilities Balance December 31, 2022 $ (534,000) Fair Value Adjustment - March 31, 2023 (629,000) Balance March 31, 2023 $ (1,163,000)

Restructuring Charges (Tables)

Restructuring Charges (Tables)	3 Months Ended
	Mar. 31, 2023
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Expenses	The following table sets forth certain details associated with the restructuring charges incurred in the three months ended March 31, 2023 and the obligations recorded for the expenses associated with the Plan (in thousands). It is anticipated the Plan will be completed by mid-2023. Balances Cash Balances December 31, 2022 Charges (payments) March 31, 2023 Employee severance and benefits 935 $ — $ (370) $ 565 Legal and professional fees 35 15 (23) 27 Other 15 — — 15 $ 985 $ 15 $ (393) $ 607

Background and Basis of Prese_2

Background and Basis of Presentation (Details)		3 Months Ended
	Aug. 26, 2022	Mar. 31, 2023 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments		1
Reverse stock split, conversion ratio	0.04

Going Concern (Details)

Going Concern (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 3,121	$ 9,038

Net Loss per Share - Additional

Net Loss per Share - Additional Information (Details) - shares	Nov. 30, 2022	Sep. 30, 2022	Aug. 31, 2022	Aug. 31, 2021
Healios Framework Agreement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares called by warrants (in shares)	9,109,090	2,000,000	1,920,000	400,000

Net Loss per Share - Instrument

Net Loss per Share - Instruments Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	15,484,902	1,774,090
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	1,196,530	1,307,832
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	859,282	66,258
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	13,429,090	400,000

Property and Equipment, net - S

Property and Equipment, net - Schedule of Property and Equipment, net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 13,491	$ 13,823
Accumulated depreciation and amortization	(9,412)	(9,609)
Property and equipment, net	4,079	4,214
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,244	7,576
Office equipment and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,934	3,934
Equipment and leasehold improvements not yet in service
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,313	$ 2,313

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Loss from impairment of assets		$ 7.2
Disposal of obsolete equipment	$ 0.1

Collaborative Arrangements an_3

Collaborative Arrangements and Revenue Recognition - Additional Information (Details)	1 Months Ended		3 Months Ended		12 Months Ended
	Sep. 30, 2022 USD ($) shares	Aug. 31, 2021 USD ($) shares	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2017 milestone	Dec. 31, 2022 USD ($)	Nov. 30, 2022 shares	Aug. 31, 2022 shares
Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accounts receivable, payments due within period of invoicing			30 days
Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accounts receivable, payments due within period of invoicing			45 days
Healios Framework Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accounts receivable from Healios			$ 700,000	$ 1,600,000
Potential revenue from milestones		$ 3,000,000
Milestones obligated to pay						$ 1,100,000
Received milestones payment	$ 1,900,000
Warrants issued (in shares) | shares		2
Shares called by warrants (in shares) | shares	2,000,000	400,000					9,109,090	1,920,000
Revenue recognized			0	2,800,000
Revenue recognized from performance obligations satisfied in previous periods			$ 0	$ 0
Healios | Regulatory and sales milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of future milestones achieved | milestone					2

Collaborative Arrangements an_4

Collaborative Arrangements and Revenue Recognition - Schedule of Contract Revenues Disaggregated by Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	$ 0	$ 2,912
Healios | Point in Time
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	0	0
Healios | Point in Time | Product supply revenue
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	0	0
Healios | Point in Time | Service revenue
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	0	0
Healios | Over Time
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	0	2,912
Healios | Over Time | Product supply revenue
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	0	0
Healios | Over Time | Service revenue
Disaggregation of Revenue [Line Items]
Total disaggregated revenues	$ 0	$ 2,912

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0.7	$ 1.4
Unrecognized compensation cost of unvested stock awards	$ 4.6
2019 Equity And Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for equity incentive plan (in shares)			1,700,000
Common stock shares issued (in shares)	627,290
Shares available for issuance (in shares)	27,491
Shares of common stock outstanding (in shares)	1,626,312
Expired Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares issued (in shares)	11,289
Shares of common stock outstanding (in shares)	28,404
Inducement Awards Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock outstanding (in shares)	429,500

Stockholders_ Equity and Warr_2

Stockholders’ Equity and Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands

1 Months Ended

3 Months Ended

Apr. 18, 2023

Nov. 09, 2022

Sep. 22, 2022

Aug. 29, 2022

Aug. 17, 2022

Aug. 15, 2022

May 12, 2022

Aug. 31, 2021

Nov. 30, 2019

Mar. 31, 2023

Sep. 30, 2022

Mar. 31, 2022

Dec. 31, 2022

Jun. 30, 2021

Class of Stock [Line Items]

Common stock, shares authorized (in shares)

600,000,000

600,000,000

600,000,000

Preferred stock, shares authorized (in shares)

10,000,000

10,000,000

10,000,000

Preferred stock, shares issued (in shares)

0

0

0

Gain on change in fair value of warrants

$ (629)

$ 0

Warrant issuance costs allocated to equity

400

Healios

Class of Stock [Line Items]

Warrant, exercise cap triggering percentage

19.90%

Warrants

Class of Stock [Line Items]

Fair value of warrant liabilities

1,163

$ 534

Pre-Funded Warrants and Common Warrants

Class of Stock [Line Items]

Reclass of warrant liability to additional paid-in capital upon exercise

$ 800

Issuance costs allocated to warrant liabilities

$ 500

Healios | 2021 Warrants

Class of Stock [Line Items]

Shares called by warrants (in shares)

400,000

Healios | 2021 Warrant, Type One

Class of Stock [Line Items]

Exercise price of warrant (in dollars per share)

$ 45

Warrants, exercisable period

60 days

Shares called by warrants (in shares)

120,000

Healios | 2021 Warrant, Type Two

Class of Stock [Line Items]

Exercise price of warrant (in dollars per share)

$ 60

Warrants, exercisable period

60 days

Shares called by warrants (in shares)

280,000

Aspire Capital

Class of Stock [Line Items]

Common stock share issued (in shares)

272,000

Issuance of common stock per share (in dollars per share)

$ 17.66

Placement Agency Agreement With Alliance Global Partners | Alliance Global Partners

Class of Stock [Line Items]

Placement fee

$ 400

$ 800

Placement fee reimbursement

$ 100

$ 100

Placement Agency Agreement With Alliance Global Partners | Alliance Global Partners | Subsequent Event

Class of Stock [Line Items]

Placement fee

$ 200

Placement fee reimbursement

$ 100

August 2022 Purchase Agreement

Class of Stock [Line Items]

Shares issued and sold (in shares)

1,200,000

Proceeds from the issuance of common stock and warrants, net of issuance cost

$ 11,000

Participation right percentage

30%

August 2022 Purchase Agreement | August 2022 Pre-Funded Warrants

Class of Stock [Line Items]

Shares issued and sold (in shares)

720,000

Number of shares called by each warrant (in shares)

1

Exercise price of warrant (in dollars per share)

$ 0.0025

Gain on change in fair value of warrants

$ 800

Reclass of warrant liability to additional paid-in capital upon exercise

$ 3,800

August 2022 Purchase Agreement | August 2022 Common Warrant

Class of Stock [Line Items]

Shares issued and sold (in shares)

1,920,000

Number of shares called by each warrant (in shares)

1

Exercise price of warrant (in dollars per share)

$ 6.385

Warrants, exercisable period

6 months

Warrants term

5 years

August 2022 Purchase Agreement | August 2022 Warrant

Class of Stock [Line Items]

Exercise price of warrant (in dollars per share)

$ 6.25

August 2022 Purchase Agreement | Common Stock

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

August 2022 Purchase Agreement | Common Stock | August 2022 Pre-Funded Warrants

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

August 2022 Purchase Agreement | Common Stock | August 2022 Common Warrant

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

August 2022 Purchase Agreement Amendment | August 2022 Common Warrant

Class of Stock [Line Items]

Warrants, exercisable period

6 months

Warrants term

7 years

August 2022 Purchase Agreement Amendment | September Warrants

Class of Stock [Line Items]

Exercise price of warrant (in dollars per share)

$ 6.385

Warrants term

7 years

Shares called by warrants (in shares)

2,000,000

November 2022 Purchase Agreement

Class of Stock [Line Items]

Shares issued and sold (in shares)

3,927,275

Proceeds from the issuance of common stock and warrants, net of issuance cost

$ 5,000

November 2022 Purchase Agreement | November 2022 Pre-Funded Warrants

Class of Stock [Line Items]

Shares issued and sold (in shares)

1,077,270

Number of shares called by each warrant (in shares)

1

Exercise price of warrant, price difference (in dollars per share)

$ 0.0001

November 2022 Purchase Agreement | November 2022 Common Warrants

Class of Stock [Line Items]

Shares issued and sold (in shares)

10,009,090

Number of shares called by each warrant (in shares)

1

Exercise price of warrant (in dollars per share)

$ 1.10

Warrants term

5 years

November 2022 Purchase Agreement | Common Stock

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

November 2022 Purchase Agreement | Common Stock | November 2022 Pre-Funded Warrants

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

November 2022 Purchase Agreement | Common Stock | November 2022 Common Warrants

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

2

April 2023 Purchase Agreement | Subsequent Event

Class of Stock [Line Items]

Shares issued and sold (in shares)

2,315,000

Exercise price of warrant (in dollars per share)

$ 1

Proceeds from the issuance of common stock and warrants, net of issuance cost

$ 3,400

April 2023 Purchase Agreement | April 2023 Pre-Funded Warrants | Subsequent Event

Class of Stock [Line Items]

Shares issued and sold (in shares)

1,370,000

Number of shares called by each warrant (in shares)

1

Exercise price of warrant (in dollars per share)

$ 0.0001

April 2023 Purchase Agreement | April 2023 Common Warrants | Subsequent Event

Class of Stock [Line Items]

Shares issued and sold (in shares)

3,685,000

Number of shares called by each warrant (in shares)

1

Exercise price of warrant (in dollars per share)

$ 0.96

Warrants, exercisable period

6 months

Warrants term

7 years

April 2023 Purchase Agreement | Common Stock | Subsequent Event

Class of Stock [Line Items]

Number of shares called by each warrant (in shares)

1

2022 Equity Facility | Aspire Capital

Class of Stock [Line Items]

Number of shares committed to be purchased (in shares)

$ 100,000

2021 Equity Facility | Aspire Capital

Class of Stock [Line Items]

Number of shares committed to be purchased (in shares)

$ 100,000

Common stock registered for resale (in shares)

1,600,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Warrants $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ (534)
Fair Value Adjustment	(629)
Ending balance	$ (1,163)

Restructuring Charges - Additio

Restructuring Charges - Additional Information (Details)	1 Months Ended
	Jun. 30, 2022
Restructuring and Related Activities [Abstract]
Percentage of reduction in workforce	70%

Restructuring Charges - Schedul

Restructuring Charges - Schedule of Restructuring Reserve (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance	$ 985
Charges	15
Cash payments	(393)
Ending balance	607
Employee severance and benefits
Restructuring Reserve [Roll Forward]
Beginning balance	935
Charges	0
Cash payments	(370)
Ending balance	565
Legal and professional fees
Restructuring Reserve [Roll Forward]
Beginning balance	35
Charges	15
Cash payments	(23)
Ending balance	27
Other
Restructuring Reserve [Roll Forward]
Beginning balance	15
Charges	0
Cash payments	0
Ending balance	$ 15

Income Taxes (Detail)

Income Taxes (Detail) $ in Millions	Mar. 31, 2023 USD ($)
Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 24.4
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	348.1
State and Local
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 140.3

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 18, 2023	Nov. 09, 2022	Aug. 15, 2022	Apr. 17, 2023
Placement Agency Agreement With Alliance Global Partners | Alliance Global Partners
Subsequent Event [Line Items]
Placement fee		$ 0.4	$ 0.8
Placement fee reimbursement		$ 0.1	$ 0.1
Subsequent Event | August Warrants And September Warrants Amendment
Subsequent Event [Line Items]
Exercise price of warrant (in dollars per share)				$ 0.96
Subsequent Event | August Warrants And September Warrants Amendment | August Warrants
Subsequent Event [Line Items]
Shares called by warrants (in shares)				1,920,000
Subsequent Event | August Warrants And September Warrants Amendment | September Warrants
Subsequent Event [Line Items]
Shares called by warrants (in shares)				1,760,000
Subsequent Event | Placement Agency Agreement With Alliance Global Partners | Alliance Global Partners
Subsequent Event [Line Items]
Placement fee	$ 0.2
Placement fee reimbursement	$ 0.1
Subsequent Event | April 2023 Purchase Agreement
Subsequent Event [Line Items]
Exercise price of warrant (in dollars per share)	$ 1
Shares issued in offering (in shares)	2,315,000
Proceeds from the issuance of common stock and warrants, net of issuance cost	$ 3.4
Subsequent Event | April 2023 Purchase Agreement | Common Stock
Subsequent Event [Line Items]
Number of shares called by each warrant (in shares)	1
Subsequent Event | April 2023 Purchase Agreement | April 2023 Pre-Funded Warrants
Subsequent Event [Line Items]
Exercise price of warrant (in dollars per share)	$ 0.0001
Shares issued in offering (in shares)	1,370,000
Number of shares called by each warrant (in shares)	1
Subsequent Event | April 2023 Purchase Agreement | April 2023 Common Warrants
Subsequent Event [Line Items]
Exercise price of warrant (in dollars per share)	$ 0.96
Shares issued in offering (in shares)	3,685,000
Warrants, exercisable period	6 months
Number of shares called by each warrant (in shares)	1
Warrants term	7 years