0000950170-23-021301 | 10-Q | XBRL Viewer

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Balance Sheet Details - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Insurance	$ 460	$ 513
Other	9	10
Total	$ 469	$ 523

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total Histogen, Inc. Stockholders' Equity (Deficit) [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2021	$ 20,186		$ 5	$ 98,839	$ (77,652)	$ 21,192	$ (1,006)
Beginning balance, shares at Dec. 31, 2021			2,497,450
Issuance of common stock, net of issuance costs	(9)			(9)		(9)
Issuance of redeemable convertible preferred stock, net of issuance costs		$ 4,296
Issuance of redeemable convertible preferred stock, net of issuance costs, shares		5,000
Stock-based compensation expense	165			165		165
Net loss	(684)				(673)	(673)	(11)
Ending balance at Mar. 31, 2022	19,658		$ 5	98,995	(78,325)	20,675	(1,017)
Ending balance, shares at Mar. 31, 2022			2,497,450
Ending balance at Mar. 31, 2022		$ 4,296
Ending balance, shares at Mar. 31, 2022		5,000
Beginning balance at Dec. 31, 2022	13,376		$ 5	102,673	(88,273)	14,405	(1,029)
Beginning balance, shares at Dec. 31, 2022			4,271,759
Stock-based compensation expense	419			419		419
Net loss	(3,473)				(3,470)	(3,470)	(3)
Ending balance at Mar. 31, 2023	$ 10,322		$ 5	$ 103,092	$ (91,743)	$ 11,354	$ (1,032)
Ending balance, shares at Mar. 31, 2023			4,271,759

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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- Definition

Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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+ Details

- Definition

Carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.

+ References + Details

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Payments of Lease Liabilities

At March 31, 2023, future minimum payments of lease liabilities were as follows (in thousands):


	Operating Lease			Finance Lease
2023 (Remaining 9 months)		588			8
2024		803			5
2025		827			—
2026		853			—
Thereafter		4,330			—
Total minimum lease payments		7,401			13
Less: imputed interest		(2,838	)		(1	)
Total future minimum lease payments		4,563			12
Less: current obligations under leases		(251	)		(9	)
Noncurrent lease obligations	$	4,312		$	3

Description of Business and Basis of Presentation - Additional Information (Detail) $ in Thousands		3 Months Ended
	Jun. 02, 2022	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)
Description of Business and Basis of Presentation [Line Items]
Reverse stock split description		one-for-twenty
Reverse stock split conversion ratio	0.20
Accumulated deficit		$ (91,743)	$ (88,273)
Cash and cash equivalents		$ 9,658	$ 12,109	$ 17,848

Revenues - Additional Information (Detail)	1 Months Ended				3 Months Ended		12 Months Ended
Revenues - Additional Information (Detail)	Mar. 31, 2022 USD ($)	Jan. 31, 2020 USD ($) Kilograms	Mar. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Revenue					$ 5,000	$ 3,755,000
Deferred revenue					100,000		$ 100,000
2017 Allergan Agreement [Member]
Disaggregation of Revenue [Line Items]
Cash payment received				$ 11,000,000.0
Potential additional payments				5,500,000
2019 Allergan Amendment Agreement [Member]
Disaggregation of Revenue [Line Items]
One-time payment			$ 7,500,000
2020 Allergan Amendment Agreement [Member]
Disaggregation of Revenue [Line Items]
Revenue					0	0
Up front payment received		$ 1,000,000.0
Additional quantity of product to be supplied \| Kilograms		200
Revenue related to Potential Future Improvements		$ 200,000
Revenue recognized					5,000	5,000
2022 Allergan Letter Agreement [Member]
Disaggregation of Revenue [Line Items]
Potential milestone payment				5,500,000
Potential milestone payment recognized	$ 3,800,000
Product [Member] \| 2017 Allergan Agreement [Member] \| Minimum [Member]
Disaggregation of Revenue [Line Items]
Sales target for additional potential payment payout				60,000,000.0
Product [Member] \| 2022 Allergan Letter Agreement [Member] \| Minimum [Member]
Disaggregation of Revenue [Line Items]
Sales target for potential milestone payment				$ 60,000,000.0
License [Member]
Disaggregation of Revenue [Line Items]
Revenue					$ 5,000	$ 3,755,000
License [Member] \| 2019 Allergan Amendment Agreement [Member]
Disaggregation of Revenue [Line Items]
Revenue			$ 7,500,000
License [Member] \| 2022 Allergan Letter Agreement [Member]
Disaggregation of Revenue [Line Items]
Revenue							$ 3,800,000

Stockholders' Equity - Summary of Valuation of Stock Option Awards (Detail)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility	91.75%	79.00%
Risk-free interest rate	3.91%	1.90%
Expected option life (in years)	6 years 29 days	6 years 29 days

Stockholders' Equity - Summary of Stock Option Activity (Details) - 2017 and 2020 Plan [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Beginning balance	113,279
Number of Options, Granted	316,110
Number of Options, Cancelled / Forfeited	(81,832)
Number of Options, Ending balance	347,557	113,279
Number of Options, Vested and exercisable	24,447
Weighted-Average Exercise Price, Beginning balance	$ 21.30
Weighted-Average Exercise Price, Granted	0.95
Weighted-Average Exercise Price, Cancelled / Forfeited	18.83
Weighted-Average Exercise Price, Ending balance	3.37	$ 21.30
Weighted-Average Exercise Price, Vested and exercisable	$ 33.88
Weighted-Average Remaining Contractual Term Outstanding	9 years 6 months 29 days	8 years 1 month 2 days
Weighted-Average Remaining Contractual Term Outstanding, Vested and exercisable	5 years 10 days
Aggregate Intrinsic Value Outstanding	$ 82

Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,210	$ 1,210
Less: accumulated depreciation and amortization	(812)	(774)
Property and equipment, net	398	436
Lab and Manufacturing Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	937	937
Office Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	225	225
Software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 48	$ 48

Balance Sheet Details - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Current portion of finance lease liabilities	$ 9	$ 9
Accrued compensation	312	160
Preclinical and clinical related expenses	89	150
Legal fees	103	44
Accrued franchise tax	50	162
Other	66	70
Total	$ 629	$ 595

Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Apr. 30, 2019	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Mar. 01, 2020	Jul. 31, 2010
Operating Leased Assets [Line Items]
Lease commencement date		Mar. 01, 2020
Lease expiration date		Aug. 31, 2031
Lessee, operating lease, existence of option to extend		false
Rent abatement term		7 months
Tenant improvement allowance on modified lease		$ 2,200,000
Right-of-use asset		4,576,000		$ 4,658,000	$ 4,500,000
Operating lease liability		$ 4,563,000			$ 4,500,000
Operating lease remaining term		8 years 4 months 24 days
Finance lease remaining term		1 year 2 months 12 days
Operating lease weighted-average discount rate					12.20%
Finance lease weighted-average discount rate					10.00%
Issuance of preferred stock, value			$ (9,000)
Accrued liabilities		$ 0
Litigation and legal liability		0
PUR Biologics, LLC [Member]
Operating Leased Assets [Line Items]
Upfront cash paid	$ 500,000
Amount forgiven	22,000
Repayments of outstanding payable assumed	23,000
Development Assets [Member]
Operating Leased Assets [Line Items]
Milestone and royalty payment obligations	$ 400,000
Percentage of royalties on net sales	5.00%
Development Assets [Member] \| Commercialization Milestone [Member]
Operating Leased Assets [Line Items]
Milestone and royalty payment obligations	$ 400,000
Development Assets [Member] \| Product [Member] \| Estimated Sales [Member]
Operating Leased Assets [Line Items]
Revenue target for milestone achievement	$ 500,000
Series D Convertible Preferred Stock [Member] \| Development Assets [Member] \| PUR Biologics, LLC [Member]
Operating Leased Assets [Line Items]
Issuance of preferred stock, shares	8,366
Issuance of preferred stock, value	$ 1,750,000
Contingent Liability [Member]
Operating Leased Assets [Line Items]
Payment for milestone		0		0
Common Stock Purchase Agreement with Pfizer Inc. [Member]
Operating Leased Assets [Line Items]
Payment to related party						$ 18,000,000.0
Collaboration Agreement with Amerimmune [Member]
Operating Leased Assets [Line Items]
Payment for milestone		0		$ 0
Building Improvements [Member]
Operating Leased Assets [Line Items]
Increase (decrease) in operating lease liability		400,000
Increase (decrease) in right-of-use-asset		$ 400,000
Extension of rent abatement		2 months
Amendment [Member]
Operating Leased Assets [Line Items]
Tenant improvement allowance on modified lease		$ 2,300,000
Increase (decrease) in operating lease liability		300,000
Increase (decrease) in right-of-use-asset		300,000
Letter of Credit [Member]
Operating Leased Assets [Line Items]
Security deposit		300,000
Letter of credit		300,000
Letter of Credit [Member] \| Amendment [Member]
Operating Leased Assets [Line Items]
Letter of credit		400,000
Maximum [Member]
Operating Leased Assets [Line Items]
Tenant improvement allowance on modified lease		$ 2,200,000
Maximum [Member] \| Development Assets [Member] \| PUR Biologics, LLC [Member]
Operating Leased Assets [Line Items]
Potential cash payout	$ 6,250,000

Property and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

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


	March 31, 2023			December 31, 2022
Lab and manufacturing equipment	$	937		$	937
Office furniture and equipment		225			225
Software		48			48
Total		1,210			1,210
Less: accumulated depreciation and amortization		(812	)		(774	)
Property and equipment, net	$	398		$	436

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 9,658	$ 12,109
Restricted cash	300	400
Accounts receivable, net	23	99
Prepaid and other current assets	627	848
Total current assets	10,608	13,456
Property and equipment, net	398	436
Right-of-use asset	4,576	4,658
Other assets	469	523
Total assets	16,051	19,073
Current liabilities
Accounts payable	441	382
Accrued liabilities	629	595
Current portion of lease liabilities	251	238
Current portion of deferred revenue	19	19
Total current liabilities	1,340	1,234
Lease liabilities, non-current	4,312	4,379
Deferred revenue, non-current	74	79
Finance lease liability, non-current	3	5
Total liabilities	5,729	5,697
Commitments and contingencies (Note 8)
Stockholders' equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at March 31, 2023 and December 31, 2022; no shares issued and outstanding at March 31, 2023 and December 31, 2022
Common stock, $0.0001 par value; 200,000,000 shares authorized at March 31, 2023 and December 31, 2022; 4,271,759 shares issued and outstanding at March 31, 2023 and December 31, 2022	5	5
Additional paid-in capital	103,092	102,673
Accumulated deficit	(91,743)	(88,273)
Total Histogen, Inc. stockholders' equity	11,354	14,405
Noncontrolling interest	(1,032)	(1,029)
Total equity	10,322	13,376
Total liabilities and stockholders’ equity	$ 16,051	$ 19,073

Balance Sheet Details - Summary of Prepaid and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Insurance	$ 379	$ 626
Prepaid rent	84	81
Pre-clinical and clinical related expenses	76	64
Other	88	77
Total	$ 627	$ 848

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Cash flows from operating activities
Net loss	$ (3,473)	$ (684)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	38	31
Stock-based compensation	419	165
Gain from sale of subsidiary	(1)
Changes in operating assets and liabilities:
Accounts receivable	76	98
Prepaid expenses and other current assets	221	(295)
Other assets	54	57
Accounts payable	59	(303)
Accrued liabilities	34	591
Right-of-use asset and lease liabilities, net	28
Deferred revenue	(5)	(5)
Net cash used in operating activities	(2,550)	(345)
Cash flows from investing activities
Cash proceeds from sale of subsidiary	1
Cash paid for property and equipment		(15)
Net cash provided by (used in) investing activities	1	(15)
Cash flows from financing activities
Proceeds from the issuance of common stock, net of issuance costs		(9)
Repayment of finance lease obligations	(2)	(2)
Issuance costs for redeemable convertible preferred stock		(466)
Net cash used in financing activities	(2)	(477)
Net decrease in cash, cash equivalents and restricted cash	(2,551)	(837)
Cash, cash equivalents and restricted cash, beginning of period	12,509	19,085
Cash, cash equivalents and restricted cash, end of period	9,958	18,248
Reconciliation of cash, cash equivalents and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	9,658	17,848
Restricted cash	300	400
Total cash, cash equivalents and restricted cash	$ 9,958	18,248
Supplemental disclosure of cash flow information
Cash paid for interest		1
Noncash investing and financing activities
Property and equipment purchased on account, not yet paid		183
Issuance of redeemable convertible preferred stock, proceeds held in escrow		4,762
Fair value of warrants issued to Placement Agent		$ 34

Balance Sheet Details

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balance Sheet Details

4. Balance Sheet Details

Prepaid and other current assets consisted of the following (in thousands):


	March 31, 2023		December 31, 2022
Insurance	$	379	$	626
Prepaid rent		84		81
Pre-clinical and clinical related expenses		76		64
Other		88		77
Total	$	627	$	848

Other assets consisted of the following (in thousands):


	March 31, 2023		December 31, 2022
Insurance	$	460	$	513
Other		9		10
Total	$	469	$	523

Accrued liabilities consisted of the following (in thousands):


	March 31, 2023		December 31, 2022
Current portion of finance lease liabilities	$	9	$	9
Accrued compensation		312		160
Preclinical and clinical related expenses		89		150
Legal fees		103		44
Accrued franchise tax		50		162
Other		66		70
Total	$	629	$	595

Commitments and Contingencies - Schedule of Future Minimum Payments of Lease Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 01, 2020
Operating Lease
2023 (Remaining 9 months)	$ 588
2024	803
2025	827
2026	853
Thereafter	4,330
Total minimum lease payments	7,401
Less: imputed interest	(2,838)
Total future minimum lease payments	4,563		$ 4,500
Less: current obligations under leases	(251)	$ (238)
Operating Lease, Liability, Noncurrent	4,312	4,379
Finance Lease
2023 (Remaining 9 months)	8
2024	5
Total minimum lease payments	13
Less: imputed interest	(1)
Total future minimum lease payments	12
Less: current obligations under leases	(9)	(9)
Finance Lease, Liability, Noncurrent	$ 3	$ 5

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2023	May 11, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Trading Symbol	HSTO
Entity Registrant Name	Histogen Inc.
Entity Central Index Key	0001383701
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	10655 Sorrento Valley Road
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	(858)
Local Phone Number	526-3100
Entity File Number	001-36003
Entity Tax Identification Number	20-3183915
Entity Common Stock, Shares Outstanding		4,271,759
Document Quarterly Report	true
Document Transition Report	false

Subsequent Events

3 Months Ended

Mar. 31, 2023

Subsequent Events [Abstract]

Subsequent Events

10. Subsequent Events

On April 3, 2023, the Company entered into an Exclusive License Agreement (the “Agreement”) with Johns Hopkins University (“Johns Hopkins”), pursuant to which Johns Hopkins granted the Company an exclusive license to certain intellectual property associated with the use of emricasan for the treatment of disease in humans resulting from viral or bacterial infections (including but not limited to, MRSA, VRSA, and SARS-CoV-2). In exchange, the Company agreed to pay Johns Hopkins an upfront license fee, reimbursement of certain patent costs, payments upon meeting certain milestones of up to $2.1 million, and royalty payments. The Agreement contains customary provisions on, among other things, termination, indemnification and patent prosecution and maintenance of the licensed intellectual property portfolio.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Description of Business

Histogen Inc. (the “Company,” “Histogen,” “we,” or the “combined company”), formerly known as Conatus Pharmaceuticals Inc. (“Conatus”), was incorporated in the state of Delaware on July 13, 2005. The Company is a clinical-stage therapeutics company focused on developing potential first-in-class clinical and preclinical small molecule pan-caspase and caspase selective inhibitors that protect the body’s natural process to restore immune function.

On January 28, 2020, the Company, then operating as Conatus, entered into an Agreement and Plan of Merger and Reorganization, as amended (the “Merger Agreement”), with privately-held Histogen, Inc. (“Private Histogen”) and Chinook Merger Sub, Inc., a wholly-owned subsidiary of the Company (“Merger Sub”). Under the Merger Agreement, Merger Sub merged with and into Private Histogen, with Private Histogen surviving as a wholly-owned subsidiary of the Company (the “Merger”). On May 26, 2020, the Merger was completed. Conatus changed its name to Histogen Inc., and Private Histogen, which remains as a wholly-owned subsidiary of the Company, changed its name to Histogen Therapeutics Inc. On May 27, 2020, the combined company’s common stock began trading on The Nasdaq Capital Market under the ticker symbol “HSTO”.

Reverse Stock Split

On June 2, 2022, the Company’s Board of Directors approved a one-for-twenty reverse stock split of its then outstanding common stock (the “Reverse Stock Split”) with any fractional shares resulting from the Reserve Stock Split rounded down to the next whole share of common stock. The par value and the authorized shares of the common stock were not adjusted as a result of the Reverse Stock Split. All references to share and per share amounts for all periods presented in the condensed consolidated financial statements have been retrospectively restated to reflect this Reverse Stock Split. Additionally, all rights to receive shares of common stock under outstanding warrants, options, and restricted stock units (“RSUs”) were adjusted to give effect of the reverse stock split. Furthermore, remaining shares of common stock available for future issuance under stock-based payment award plans and employee stock purchase plans were adjusted to give effect to the Reverse Stock Split.

Liquidity and Going Concern

The Company has incurred operating losses and negative cash flows from operations and had an accumulated deficit of $91.7 million as of March 31, 2023. The Company expects operating losses and negative cash flows from operations to continue for the foreseeable future. As of March 31, 2023, the Company had $9.7 million in cash and cash equivalents, which will not be sufficient to sustain its operations for at least twelve months following the date these condensed consolidated financial statements are issued.

The Company has not yet established ongoing sources of revenues sufficient to cover its operating costs and will need to continue to raise additional capital to support its future operating activities, including progression of its development programs, preparation for potential commercialization, and other operating costs. Management’s plans with regard to these matters include entering into a combination of additional debt or equity financing arrangements, strategic partnerships, collaboration and licensing arrangements, or other similar arrangements. There can be no assurance that the Company will be able to obtain additional financing on terms acceptable to the Company, on a timely basis or at all. These factors, among several others, raise substantial doubt about the Company’s ability to continue as a going concern.

The condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. Based on the current business plan and operating budget, there is substantial doubt about the Company’s ability to continue as a going concern within one year from the date the condensed consolidated financial statements are issued. The condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of this uncertainty.

Basis of Presentation and Principles of Consolidation

The condensed consolidated financial statements include the accounts of the Company and its controlled subsidiaries, including Histogen Therapeutics, Inc., and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). All intercompany balances and transactions have been eliminated upon consolidation.

The Company acquired Centro De Investigacion de Medicina Regenerativa, S.A. de C.V. (“CIMRESA”), a company in Mexico, during 2018 to facilitate a potential clinical development program for HST-001, or hair stimulating complex (“HSC”). This was a wholly-owned subsidiary intended to pursue registration with the COFEPRIS (Mexico equivalent to Food and Drug Administration). Since the Company acquired CIMRESA in 2018, there have been no financial or operational activities. On January 17, 2023, the Company sold the wholly-owned subsidiary, CIMRESA, and deconsolidated the former subsidiary, resulting in a gain during the three months ended March 31, 2023.

The Company holds a majority interest in Adaptive Biologix, Inc. (“AB”, formerly Histogen Oncology, LLC). AB was formed to develop and market applications for the treatment of cancer. The Company consolidates AB into its condensed consolidated financial statements (refer to Note 2 for further information).

Unaudited Interim Financial Information

The unaudited condensed consolidated financial statements for the three months ended March 31, 2023 and 2022 have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and GAAP. Accordingly, these condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of Management, these unaudited interim condensed consolidated financial statements contain all adjustments necessary, all of which are of a normal and recurring nature, to present fairly the Company’s financial position, results of operations, and cash flows. Interim results are not necessarily indicative of results for a full year or future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes thereto for the year ended December 31, 2022 included in the Annual Report on Form 10-K that the Company filed with the SEC on March 9, 2023.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and the disclosure of contingent assets and liabilities and contingencies at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the periods presented. Management believes that these estimates and assumptions are reasonable, however, actual results may differ and could have a material effect on future results of operations and financial position. Though the impact of the COVID-19 pandemic to our business and operating results presents additional uncertainty, the Company continues to use the best information available to them in their significant accounting estimates.

Significant estimates and assumptions include those related to accrued research and development expenses, the useful lives of property and equipment, discount rates used in recognizing contracts containing leases, unrecognized tax benefits, volatility used for stock-based compensation option pricing, and best estimate of standalone selling price of revenue deliverables. Actual results may materially differ from those estimates.

Variable Interest Entities

The Company determined that AB is a variable interest entity (“VIE”) and that the Company is its primary beneficiary. The Company holds greater than 50% of the shares and has the authority to manage the business and affairs of the VIE. AB’s other shareholder does not have a controlling interest.

A VIE is typically an entity for which the Company has less than a 100% equity interest but controls the decision making over the business and affairs of the entity, directs the decisions driving the economic performance of such entity and participates in the profit and losses of such an entity. The Company weighed both quantitative and qualitative information about the different risks and reward characteristics of each entity and the significance of that entity to the consolidating group in the aggregate.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker, the Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments purchased with an original maturity date of ninety days or less to be cash equivalents. Cash and cash equivalents include cash in readily available checking, money market accounts and brokerage accounts.

The Company’s current restricted cash consists of cash held as collateral for a letter of credit issued as a security deposit for the lease of the Company’s headquarters and is required to be held throughout the lease term.

Risks and Uncertainties

Credit Risk

At certain times throughout the year, the Company may maintain deposits in federally insured financial institutions in excess of federally insured limits.

Customer Risk

During the three months ended March 31, 2023 and 2022, one customer accounted for 100% of total revenues.

COVID-19

The cumulative effect of the COVID-19 outbreak and associated disruptions have had, and may continue to have, an adverse impact on the Company’s business and its results of operations. While many countries have removed or reduced restrictions initially implemented in response to COVID-19, the COVID-19 outbreak continues to evolve as of the date these condensed consolidated financial statements were available to be issued and will depend on future developments that are highly uncertain and unpredictable, including efficacy and adoption of vaccines, future resurgences of the virus and its variants, the imposition of governmental lockdowns, and quarantine and physical distancing requirements. As such, it is uncertain as to the full magnitude that the pandemic will have on the Company’s financial condition, liquidity, and future results of operations.

Accounts Receivable

Accounts receivable are generally due within 30 days and are recorded net of the allowance for doubtful accounts, if any. Management considers all accounts receivable to be fully collectible as of March 31, 2023, and accordingly, no provision for doubtful accounts was recorded.

Property and Equipment

Property and equipment are reported net of accumulated depreciation and amortization and are comprised of office furniture and equipment, lab and manufacturing equipment, and leasehold improvements. Ordinary maintenance and repairs are charged to expense, while expenditures that extend the physical or economic life of the assets are capitalized. Furniture and all equipment are depreciated over their estimated useful lives, or five years, using the straight-line method. Software is amortized over its estimated useful lives, or three years, using the straight-line method. Leasehold improvements are amortized over their estimated useful lives and limited by the remaining term of the building lease, using the straight-line method.

Valuation of Long-Lived Assets

Long-lived assets to be held and used, including property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. As of March 31, 2023, the Company has not recognized any impairment to long-lived assets.

Comprehensive Loss

The Company is required to report all components of comprehensive loss, including net loss, in the accompanying condensed consolidated financial statements in the period in which they are recognized. Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on investments and foreign currency translation adjustments. Net loss and comprehensive loss were the same for all periods presented.

Revenue Recognition

License Revenue

The Company records revenue in accordance with ASC 606, Revenue from Contracts with Customers, whereby revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration expected to be received in exchange for those goods or services. A five-step model is used to achieve the core principle: (1) identify the customer contract, (2) identify the contract’s performance obligations, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations and (5) recognize revenue when or as a performance obligation is satisfied. The Company applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. The Company applies the revenue recognition standard, including the use of any practical expedients, consistently to contracts with similar characteristics and in similar circumstances (refer to Note 5 for further information).

Grant Awards

In September 2020, the Company was approved for a grant award from the U.S. Department of Defense (“DoD”) in the amount of approximately $2.0 million to partially fund the Company’s Phase 1/2 clinical trial of HST-003 for regeneration of cartilage in the knee. The Company applies International Accounting Standard (“IAS”) 20, Accounting for Government Grants and Disclosure of Government Assistance, by analogy as there is no existing authoritative guidance under GAAP. Under the terms of the award, the DoD will reimburse the Company for certain allowable costs. The period of performance for the grant award substantially expires in September 2025 and is subject to annual and quarterly reporting requirements. As the DoD grant is a cost-type (reimbursement) grant, the Company must incur program expenses in accordance with the Statement of Work and approved budget in order to be reimbursed by the DoD. The Company will recognize funding received from the grant award as a reduction of research and development expenses in the period in which qualifying expenses have been incurred, as the Company is reasonably assured that the expenses will be reimbursed and the funding is collectible. For the three months ended March 31, 2023 and 2022, qualifying expenses totaling $23 thousand and $0.2 million have been incurred with a corresponding reduction of research and development expenses related to the award, respectively. As of March 31, 2023 and December 31, 2022, $23 thousand and $0.1 million was included in accounts receivable within the condensed consolidated balance sheets with respect to the award, respectively. The Company made the decision in December 2022 to terminate the study for futility regarding patient recruitment and redirect efforts and funding away from HST-003 to other product candidates. As of March 31, 2023, the Company had completed its HST-003 clinical study close-out activities and early terminated the grant award.

Research and Development Expenses

All research and development costs are charged to expense as incurred. Research and development expenses primarily include (i) payroll and related costs associated with research and development performed, (ii) costs related to clinical and preclinical testing of the Company’s technologies under development, and (iii) other research and development costs, net of reimbursable research and development costs incurred under the DoD grant.

General and Administrative Expenses

General and administrative expenses represent personnel costs for employees involved in general corporate functions, including finance, accounting, legal and human resources, among others. Additional costs included within general and administrative expenses consist of professional fees for legal (including patent costs), audit and other consulting services, travel and entertainment, recruiting, facility costs, general information technology costs, depreciation and amortization, and other general corporate overhead expenses.

Patent Costs

The Company expenses all costs as incurred in connection with patent applications (including direct application fees, and the legal and consulting expenses related to making such applications) and such costs are included as a component of general and administrative expenses in the accompanying consolidated statements of operations.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred income taxes are recorded for temporary differences between consolidated financial statement carrying amounts and the tax basis of assets and liabilities. Deferred tax assets and liabilities reflect the tax rates expected to be in effect for the years in which the differences are expected to reverse. No income tax expense or benefit was recorded for the three months ended March 31, 2023 and 2022, due to the full valuation allowance on the Company’s net deferred tax assets. A valuation allowance is provided if it is more likely than not that some or all the deferred tax assets will not be realized.

The Company also follows the provisions of accounting for uncertainty in income taxes which prescribes a model for the recognition and measurement of a tax position taken or expected to be taken in a tax return, and provides guidance on derecognition, classification, interest and penalties, disclosure and transition.

The Company’s policy is to recognize interest or penalties related to income tax matters in income tax expense. Interest and penalties related to income tax matters were not material for the periods presented.

Net Loss Per Share

Basic net loss per share attributable to common stockholders is computed by dividing net loss attributable to common stockholders by the weighted-average common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. For the three months ended March 31, 2023 and 2022, diluted net loss per share attributable to common stockholders is equal to basic net loss per share attributable to common stockholders as common stock equivalent shares from stock options and warrants were anti-dilutive.

The following table sets forth outstanding potentially dilutive shares that have been excluded from the calculation of diluted net loss per share attributable to common stockholders because of their anti-dilutive effect (in common stock equivalents):


	March 31, 2023		March 31, 2022
Common stock options issued and outstanding		459,237		148,865
Warrants to purchase common stock		4,876,639		1,203,807
Redeemable convertible preferred stock		—		250,000
Total anti-dilutive shares		5,335,876		1,602,672

Stock-Based Compensation

Service-Based Awards

The Company recognizes stock-based compensation expense for service-based stock options and restricted stock units (“RSUs”) over the requisite service period on a straight-line basis. Employee and director stock-based compensation for service-based stock options is measured based on estimated fair value as of the grant date using the Black-Scholes option pricing model. The Company estimates the fair value of RSUs based on the closing price of the Company’s common stock on the date of issuance. The Company uses the following assumptions for estimating fair value of service-based option grants:

Fair Value of Common Stock – The fair value of common stock underlying the option grant is determined based on observable market prices of the Company’s common stock.

Expected Volatility – Volatility is a measure of the amount by which the Company’s share price has historically fluctuated or is expected to fluctuate (i.e., expected volatility) during a period. Due to the lack of an adequate history of a public market for the trading of the Company’s common stock and a lack of adequate company-specific historical and implied volatility data, volatility has been estimated and based on the historical volatility of a group of similar companies that are publicly traded. For these analyses, the Company has selected companies with comparable characteristics, including enterprise value, risk profiles, and position within the industry, and with historical share price information sufficient to meet the expected term of the stock-based awards.

Expected Term – This is the period of time during which the options are expected to remain unexercised. Options have a maximum contractual term of ten years. The Company estimates the expected term of stock options using the “simplified method”, whereby the expected term equals the average of the vesting term and the original contractual term of the underlying option.

Risk-Free Interest Rate – This is the observed yield on zero-coupon U.S. Treasury securities, as of the day each option is granted, with a term that most closely resembles the expected term of the option.

Expected Forfeiture Rate – Forfeitures are recognized as they occur.

Performance-Based Options

Stock-based compensation expense for performance-based options is recognized based on amortizing the fair market value as of the grant date over the periods during which the achievement of the performance is probable. Performance-based options require certain performance conditions to be achieved in order for these options to vest. These options vest on the date of achievement of the performance condition.

Market-Based Options

Stock-based compensation expense for market-based options is recognized on a straight-line basis over the derived service period, regardless of whether the market condition is satisfied. Market-based options subject to market-based performance targets require achievement of the performance target in order for these options to vest. The Company estimates the fair value of market-based options as of the grant date and expected term using a Monte Carlo simulation that incorporates option-pricing inputs covering the period from the grant date through the end of the derived service period.

Recently Issued Accounting Pronouncements Not Yet Adopted

In March 2023, the FASB issued ASU No. 2023-01, Leases (Topic 842): Common Control Arrangements ("ASU 2023-01"), amending certain provisions of ASC 842 that apply to arrangements between related parties under common control. This standard amends the accounting for leasehold improvements in common-control arrangements for all entities. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years, with early adoption permitted. The Company does not expect to early adopt this guidance and is in the process of evaluating the impact of adoption of this guidance on the Company’s consolidated financial statements.

Recently Adopted Accounting Pronouncements

None.

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	4,271,759	4,271,759
Common stock, shares outstanding	4,271,759	4,271,759

Redeemable Convertible Preferred Stock

3 Months Ended

Mar. 31, 2023

Equity [Abstract]

Redeemable Convertible Preferred Stock

6. Redeemable Convertible Preferred Stock

The redeemable convertible preferred stock instruments were contingently redeemable preferred stock. Each series contained redemption features, limited voting rights, dividends, and conversion terms. The convertible preferred stock was presented on the consolidated balance sheets as mezzanine equity as of March 31, 2022. All shares of redeemable convertible preferred stock were fully redeemed and were no longer outstanding as of June 30, 2022.

March 2022 Offering

In March 2022, the Company completed a private placement offering (the “March 2022 Offering”) of (i) 2,500 shares of the Company’s Series A Redeemable Convertible Preferred Stock, par value $0.0001 per share (the “Series A Preferred Stock”), and (ii) 2,500 shares of the Company’s Series B Redeemable Convertible Preferred Stock, par value $0.0001 per share (the “Series B Preferred Stock” and together with the Series A Preferred Stock, the “Preferred Stock”), in each case, at an offering price of $952.38 per share, representing a 5% original issue discount to the stated value of $1,000 per share of Preferred Stock, for gross proceeds from the Offerings of approximately $4.76 million, before the deduction of the placement agent’s fee and other offering expenses. The shares of Series A Preferred Stock had a stated value of $1,000 per share and were convertible, at a conversion price of $20.00 per share, into 125,000 shares of common stock. The shares of Series B Preferred Stock had a stated value of $1,000 per share and were convertible, at a conversion price of $20.00 per share, into 125,000 shares of common stock. The closing occurred on March 25, 2022. The proceeds of $4.76 million were held in escrow and were only permitted to be disbursed to the Company upon conversion of the Series A and Series B Preferred Stock. Since the redeemable convertible preferred stock could have been redeemed at the option of the holder, but was not mandatorily redeemable, the redeemable preferred stock was classified as mezzanine equity and initially recognized at fair value of $4.76 million as mezzanine equity on the accompanying statement of redeemable convertible preferred stock and stockholders' equity.

The March 2022 Offering generated gross proceeds of $4.76 million and the Company incurred cash-based placement agent fees and other offering expenses of approximately $0.6 million. The proceeds were held in escrow and were only permitted to be disbursed to the Company upon conversion of the Series A and Series B Preferred Stock.

The Company’s placement agent was issued compensatory warrants to purchase up to 7.0% of the aggregate number of shares of Preferred Stock sold in the offering (on an as-converted to common stock basis), resulting in common stock warrants to purchase up to 17,501 shares of common stock, with an exercise price of 125% of the offering price, or $25.00 per share, which are exercisable 6 months after issuance on or after September 25, 2022, and expire five and a half (5.5) years following the date of issuance on September 25, 2027.

The placement agent warrants, which are recorded as a component of stockholders’ equity, were valued at an aggregate of $34 thousand dollars using the Black Scholes option pricing model based upon the following assumptions: expected volatility of 78.90%, risk-free interest rate of 2.40%, expected dividend yield of 0%, and an expected term of 5.5 years.

As of March 31, 2023, the Company had 17,501 shares of common stock reserved for issuance pursuant to the placement agent’s warrants issued by the Company in the March 2022 Offering at an exercise price of $25.00 per share.

Voting Rights

The shares of Preferred Stock had no voting rights, except that they only have the right to vote, with the holders of common stock, as a single class on a proposal to approve an amendment to our certificate of incorporation to effect a reverse stock split of our issued and outstanding common stock within a range, to be determined by our board of directors and set forth in such proposal.

Each share of Series A Preferred Stock outstanding on April 14, 2022 (the “Record Date”) had a number of votes equal to the number of shares of Common Stock issuable upon conversion of such share (whether or not such shares are then convertible). Accordingly, as of the Record Date, each share of Series A Preferred Stock had 3,776 votes, which is determined by dividing $1,000, the stated value of one share of Series A Preferred Stock, by $0.2648, the NASDAQ Minimum Price as of the closing on March 25, 2022. The holders of the Series A Preferred Stock agreed to not transfer their shares of Series A Preferred Stock until after the 2022 Annual Meeting and to vote all shares of Series A Preferred Stock in favor of the Reverse Stock Split Proposal.

Each share of Series B Preferred Stock outstanding on the Record Date entitled the holder thereof to cast 30,000 votes on the Reverse Stock Split Proposal. The holders of the Series B Preferred Stock agreed to not transfer their shares of Series B Preferred Stock until after the 2022 Annual Meeting and to vote all shares of Series B Preferred Stock in the same proportion as the aggregate shares of Common Stock and Series A Preferred Stock are voted on the Reverse Stock Split Proposal. As an example, if 70% of the aggregate votes cast by Common Stock and Series A Preferred Stock voting on the Reverse Stock Split Proposal were voted in favor thereof and 30% of the aggregate votes cast by Common Stock and Series A Preferred Stock voting on the Reverse Stock Split Proposal were voted against such Proposal, then 70% of the votes entitled to be cast by Series B Preferred Stock would have been cast in favor of the proposal and 30% of such votes would have been cast against the proposal.

Dividends

The holders of the redeemable convertible preferred stock were entitled to receive dividends on shares of Preferred Stock equal (on an as-if-converted-to-Common-Stock basis, disregarding for such purpose any conversion limitations hereunder) to and in the same form as dividends actually paid on shares of the Common Stock when, as and if such dividends are paid on shares of the Common Stock. No other dividends were payable on shares of Preferred Stock.

Conversion Rights

Each share of Preferred Stock was convertible, at any time and from time to time from and after the Reverse Stock Split Date at the option of the Holder thereof, into that number of shares of Common Stock determined by dividing the stated value per share of preferred stock by the conversion price. The shares of Series A Preferred Stock had a stated value of $1,000 per share and were convertible, at a conversion price of $20.00 per share, into 125,000 shares of common stock. The shares of Series B Preferred Stock had a stated value of $1,000 per share and were convertible, at a conversion price of $20.00 per share, into 125,000 shares of common stock.

Redemption Rights

Each share of Preferred Stock was redeemable after (i) the earlier of (1) the receipt of authorized stockholder approval for the reverse stock split and (2) the date that was 90 days following the Original Issue Date of March 25, 2022, and (ii) before the date that was 120 days after the Original Issue Date or July 23, 2022 (the “Redemption Period”), each stockholder had the right to cause the Company to redeem all or part of such stockholder’s shares of Preferred Stock at a price per share equal to 105% of the stated value of $1,000 per share.

Between June 2, 2022, and June 29, 2022, at the request of the holders, the Company redeemed for cash proceeds totaling $5.25 million ($4.76 million payment from escrow and $0.5 million redemption payment by the Company), 2,500 outstanding shares of Series A Preferred Stock and 2,500 outstanding shares of Series B Preferred Stock based on the receipt of the Redemption Notices (the “Preferred Redemption”) at a price equal to 105% of the $1,000 stated value per share, which represented all outstanding shares of Preferred Stock. The approximately $1.1 million accretion of the Series A and Series B Preferred Stock to its redemption value was recorded as a reduction to additional paid-in capital. The Company recognized a portion of the accretion as a deemed dividend related to the accretion of the discount and redemption feature of approximately $0.5 million upon redemption of Preferred Stock on the consolidated statement of operations.

On June 30, 2022, the Company filed a Certificate of Elimination with respect to the Series A Preferred Stock and Series B Preferred Stock (the “Series A Certificate of Elimination and the Series B Certificate of Elimination”), which upon filing with the Secretary of State of the State of Delaware (“Delaware Secretary”), eliminated from all matters set forth in the Certificates of Designation of Series A and Series B Preferred Stock.

As of March 31, 2023 and December 31, 2022, all shares of the Series A Preferred Stock and Series B Preferred Stock are no longer outstanding and the Company’s only remaining class of outstanding stock is its common stock, par value $0.0001 per share.

Related Parties

3 Months Ended

Mar. 31, 2023

Related Parties

9. Related Parties

Lordship

Lordship, with its predecessor entities along with its principal owner, Jonathan Jackson, have invested and been affiliated with Private Histogen since 2010. As of both March 31, 2023 and December 31, 2022, Lordship controlled approximately 2.8% of the Company’s outstanding voting shares, respectively, and currently holds two Board of Director seats.

In November 2012, Private Histogen entered into a Strategic Relationship Success Fee Agreement with Lordship (the “Success Fee Agreement”). The Success Fee Agreement causes certain payments to be made from the Company to Lordship equal to 1% of certain product revenues and 10% of certain license and royalty revenues generated from our Human Multipotent Cell Conditioned Media, or CCM, and our Human Extracellular Matrix, or hECM, in connection with the Company’s biologics technology platform. The Success Fee Agreement also stipulates that if the Company engages in a merger or sale of all or substantially all (defined as 90% or more) of its assets or equity to a third party, then the Company has the option to terminate the agreement by paying Lordship the fair market value of future payments with the minimum payment being at least equal to the most recent annual payments Lordship has received. The Success Fee Agreement was amended in August 2016, but continues to carry the same rights to certain payments. The Company recognized an expense to Lordship for the three months ended March 31, 2023 and 2022 totaling $0 and $0.4 million, respectively, all of which is included in general and administrative expenses on the accompanying condensed consolidated statements of operations. As of March 31, 2023 and December 31, 2022, there was a balance of $9 thousand and $10 thousand, respectively, paid to Lordship included as a component of other assets on the accompanying consolidated balance sheets in connection with the deferral of revenue from the Allergan license transfer agreements.

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Class Of Stock [Line Items]
Common stock warrants	4,876,639	1,203,807
Common stock available for issuance under stock plans	75,822	98,141
Redeemable convertible preferred stock		250,000
Total	5,411,698	1,700,813
Common Stock [Member]
Class Of Stock [Line Items]
Common stock warrants	68
Common stock options issued and outstanding under stock plans	352,444	148,865
Common stock options issued and outstanding outside of stock plans (inducement grant)	106,793

Description of Business and Basis of Presentation	3 Months Ended
Description of Business and Basis of Presentation	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business Histogen Inc. (the “Company,” “Histogen,” “we,” or the “combined company”), formerly known as Conatus Pharmaceuticals Inc. (“Conatus”), was incorporated in the state of Delaware on July 13, 2005. The Company is a clinical-stage therapeutics company focused on developing potential first-in-class clinical and preclinical small molecule pan-caspase and caspase selective inhibitors that protect the body’s natural process to restore immune function. On January 28, 2020, the Company, then operating as Conatus, entered into an Agreement and Plan of Merger and Reorganization, as amended (the “Merger Agreement”), with privately-held Histogen, Inc. (“Private Histogen”) and Chinook Merger Sub, Inc., a wholly-owned subsidiary of the Company (“Merger Sub”). Under the Merger Agreement, Merger Sub merged with and into Private Histogen, with Private Histogen surviving as a wholly-owned subsidiary of the Company (the “Merger”). On May 26, 2020, the Merger was completed. Conatus changed its name to Histogen Inc., and Private Histogen, which remains as a wholly-owned subsidiary of the Company, changed its name to Histogen Therapeutics Inc. On May 27, 2020, the combined company’s common stock began trading on The Nasdaq Capital Market under the ticker symbol “HSTO”. Reverse Stock Split On June 2, 2022, the Company’s Board of Directors approved a one-for-twenty reverse stock split of its then outstanding common stock (the “Reverse Stock Split”) with any fractional shares resulting from the Reserve Stock Split rounded down to the next whole share of common stock. The par value and the authorized shares of the common stock were not adjusted as a result of the Reverse Stock Split. All references to share and per share amounts for all periods presented in the condensed consolidated financial statements have been retrospectively restated to reflect this Reverse Stock Split. Additionally, all rights to receive shares of common stock under outstanding warrants, options, and restricted stock units (“RSUs”) were adjusted to give effect of the reverse stock split. Furthermore, remaining shares of common stock available for future issuance under stock-based payment award plans and employee stock purchase plans were adjusted to give effect to the Reverse Stock Split. Liquidity and Going Concern The Company has incurred operating losses and negative cash flows from operations and had an accumulated deficit of $91.7 million as of March 31, 2023. The Company expects operating losses and negative cash flows from operations to continue for the foreseeable future. As of March 31, 2023, the Company had $9.7 million in cash and cash equivalents, which will not be sufficient to sustain its operations for at least twelve months following the date these condensed consolidated financial statements are issued. The Company has not yet established ongoing sources of revenues sufficient to cover its operating costs and will need to continue to raise additional capital to support its future operating activities, including progression of its development programs, preparation for potential commercialization, and other operating costs. Management’s plans with regard to these matters include entering into a combination of additional debt or equity financing arrangements, strategic partnerships, collaboration and licensing arrangements, or other similar arrangements. There can be no assurance that the Company will be able to obtain additional financing on terms acceptable to the Company, on a timely basis or at all. These factors, among several others, raise substantial doubt about the Company’s ability to continue as a going concern. The condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. Based on the current business plan and operating budget, there is substantial doubt about the Company’s ability to continue as a going concern within one year from the date the condensed consolidated financial statements are issued. The condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of this uncertainty. Basis of Presentation and Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its controlled subsidiaries, including Histogen Therapeutics, Inc., and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). All intercompany balances and transactions have been eliminated upon consolidation. The Company acquired Centro De Investigacion de Medicina Regenerativa, S.A. de C.V. (“CIMRESA”), a company in Mexico, during 2018 to facilitate a potential clinical development program for HST-001, or hair stimulating complex (“HSC”). This was a wholly-owned subsidiary intended to pursue registration with the COFEPRIS (Mexico equivalent to Food and Drug Administration). Since the Company acquired CIMRESA in 2018, there have been no financial or operational activities. On January 17, 2023, the Company sold the wholly-owned subsidiary, CIMRESA, and deconsolidated the former subsidiary, resulting in a gain during the three months ended March 31, 2023. The Company holds a majority interest in Adaptive Biologix, Inc. (“AB”, formerly Histogen Oncology, LLC). AB was formed to develop and market applications for the treatment of cancer. The Company consolidates AB into its condensed consolidated financial statements (refer to Note 2 for further information). Unaudited Interim Financial Information The unaudited condensed consolidated financial statements for the three months ended March 31, 2023 and 2022 have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and GAAP. Accordingly, these condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of Management, these unaudited interim condensed consolidated financial statements contain all adjustments necessary, all of which are of a normal and recurring nature, to present fairly the Company’s financial position, results of operations, and cash flows. Interim results are not necessarily indicative of results for a full year or future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes thereto for the year ended December 31, 2022 included in the Annual Report on Form 10-K that the Company filed with the SEC on March 9, 2023.

Subsequent Events - Additional Information (Details) $ in Millions	Apr. 03, 2023 USD ($)
Subsequent Event [Member] \| Johns Hopkins University [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Milestone payment	$ 2.1

Commitments and Contingencies

3 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Leases

In January 2020, the Company entered into a long-term operating lease with San Diego Sycamore, LLC (“Sycamore”) for its headquarters that includes office and laboratory space. The lease commenced on March 1, 2020 and expires on August 31, 2031, with no options to renew or extend. The lease was accounted for as a modification of the Company’s existing lease with Sycamore as the lease agreement did not grant the Company an additional right-of-use asset.

The terms of the lease agreement include seven months of rent abatement at lease commencement and a tenant improvement allowance of up to $2.2 million. The tenant improvements are required to be permanently affixed to the leased office and laboratory space and do not constitute leasehold improvements of the Company. During the construction period of the tenant improvements, the lease agreement requires the Company to relocate its operations to a similar Sycamore property whereby monthly rent is substantially reduced for the duration of the construction period. The lease is subject to additional variable charges for common area maintenance, insurance, taxes and other operating costs. At lease commencement, the Company recognized a right-of-use asset and operating lease liability totaling approximately $4.5 million. The Company used a discount rate based on its estimated incremental borrowing rate to determine the right-of-use asset and operating lease liability amounts to be recognized. The Company determined its incremental borrowing rate based on the term and lease payments of the new operating lease and what it would normally pay to borrow, on a collateralized basis, over a similar term for an amount equal to the lease payments. Operating lease expense is recognized on a straight-line basis over the lease term. The terms of the lease required the Company to provide the landlord a security deposit of $0.3 million as collateral for a letter of credit issued to be held throughout the lease term. This security deposit is shown as restricted cash on the accompanying consolidated balance sheets.

In June 2021, the Company entered into the First Amendment to Lease (the “Amendment”). Pursuant to the Amendment, among other things, the Company and Sycamore agreed (i) to substitute the temporary premises, (ii) to delay the start of construction and the timing of the Company’s relocation to the replacement temporary premises, (iii) to increase the tenant improvement allowance from $2.2 million to $2.3 million, (iv) to increase the letter of credit amount from $0.3 million to $0.4 million upon commencement of the tenant improvements, and (v) to review potential subsequent reductions to the security deposit and related letter of credit requirement at certain time intervals along the lease term provided that the Company is not in default. As a result of the modification, the lease liability was remeasured using the incremental borrowing rate at the modification date and a corresponding reduction of $0.3 million was recorded to both the lease liability and right-of-use-asset.