0000950170-23-042218 | 10-Q | XBRL Viewer

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Fair Value Measurements - Additional Information (Detail) - Contingent Value Rights Agreement	6 Months Ended
	Jun. 30, 2023 USD ($)	Mar. 31, 2025 USD ($)	May 31, 2023 USD ($)	Dec. 26, 2022 USD ($)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Initial derivative liability				$ 5,000,000
Change in the estimated fair value	$ 0
Vertex Asset Purchase Agreement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amount to be received under agreement			$ 5,000,000.0
GCBP Asset Purchase Agreement \| CVR Derivative Liability non current \| Estimated Discount Rate
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative liability measurement input	0.0505
GCBP Asset Purchase Agreement \| Long-term receivable \| Estimated Discount Rate
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative asset measurement input	0.0505
GCBP Asset Purchase Agreement \| Forecast
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amount to be received under agreement		$ 5,000,000

Net Income (Loss) per Share Attributable to Common Stockholders

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Net Income (Loss) per Share Attributable to Common Stockholders

Potentially dilutive securities are excluded from the calculation of diluted net income (loss) per share attributable to common stockholders if their inclusion is anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Six Months Ended June 30,
	2023		2022
Options to purchase common stock		8,246,945		2,512,078
Common stock warrants		—		85
Total		8,246,945		2,512,163

In addition, the Catalyst Convertible Preferred Stock has also been excluded from the computation of diluted net income (loss) per share attributable to common stockholders because the contingency for conversion of these shares has not been met.

The following is a reconciliation of the numerator (net income or loss) and denominator (number of shares) used in the calculation of basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except share and per share data):


	Three Months Ended June 30,					Six Months Ended June 30,
	2023			2022		2023			2022
Numerator
Net income (loss)	$	(2,472	)	$	51,632	$	(2,212	)	$	37,096

Denominator
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, basic		37,800,121			31,477,053		37,779,384			31,466,630
Effect of dilutive stock options		—			5,872		—			2,936
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, diluted		37,800,121			31,482,925		37,779,384			31,469,566
Net income (loss) per share available for common stockholders, basic	$	(0.07	)	$	1.64	$	(0.06	)	$	1.18
Net income (loss) per share available for common stockholders, dilutive	$	(0.07	)	$	1.64	$	(0.06	)	$	1.18

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities
Net income (loss)	$ (2,212)	$ 37,096
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Stock-based compensation expense	299	861
Depreciation and amortization	4	180
Change in fair value of long-term receivables	(76)
Change in fair value of derivative liabilities	76
Bad debt expense		200
Net gain on disposal of assets	(4,736)	(57,245)
Changes in operating assets and liabilities:
Accounts and other receivables		1,618
Prepaid and other current assets	865	2,197
Accounts payable	(189)	(5,382)
Accrued compensation and other accrued liabilities	(2,746)	(3,680)
Operating lease liability and right-of-use asset	28	41
Deferred revenue		(230)
Net cash flows used in operating activities	(8,687)	(24,344)
Investing Activities
Proceeds from maturities of short-term investments		2,504
Proceeds from the sale of property and equipment		447
Proceeds from the sale of complement portfolio to Vertex	5,000	55,000
Proceeds from the sale of legacy rare bleeding disorder program to GCBP	1,000
Payment of transaction costs in connection with the sale of complement portfolio to Vertex		(2,576)
Payment of transaction costs in connection with the sale of legacy rare bleeding disorder program to GCBP	(794)
Net cash flows provided by investing activities	5,206	55,375
Financing Activities
Payment of dividends	(11,264)
Issuance of common stock from stock grants and option exercises	2	16
Net cash flows (used in) provided by financing activities	(11,262)	16
Net (decrease) increase in cash and cash equivalents	(14,743)	31,047
Cash and cash equivalents at beginning of the period	21,666	44,347
Cash and cash equivalents at end of the period	6,923	$ 75,394
Supplemental Disclosure on Non-Cash Investing and Financing Activities:
CVR derivative liability	4,530
Exercise of stock options in prepaid and other current assets	$ 22

Net Income (Loss) per Share Attributable to Common Stockholders - Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income (loss)	$ (2,472)	$ 51,632	$ (2,212)	$ 37,096
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, basic	37,800,121	31,477,053	37,779,384	31,466,630
Effect of dilutive stock options		5,872		2,936
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, diluted	37,800,121	31,482,925	37,779,384	31,469,566
Net income (loss) per share available for common stockholders, basic	$ (0.07)	$ 1.64	$ (0.06)	$ 1.18
Net income (loss) per share available for common stockholders, dilutive	$ (0.07)	$ 1.64	$ (0.06)	$ 1.18

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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+ Details

Fair Value Measurements - Changes in Estimated Fair Value of Level 3 Financial Assets and Liabilities (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Long-term receivable
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Additions in the period	$ 4,530
Changes in fair value	76
Balance at June 30, 2023	4,606
CVR Derivative Liability non current
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Additions in the period	4,530
Changes in fair value	76
Balance at June 30, 2023	$ 4,606

Stock Based Compensation - Summary of Option Activity Under Company's Equity Incentive Plans (Detail)

6 Months Ended

12 Months Ended

Jun. 30, 2023

$ / shares

Dec. 31, 2022

$ / shares

Number of Shares Underlying Outstanding Options

Number of Shares Underlying Outstanding Options, Beginning Balance | shares

8,678,767

Number of Shares Underlying Outstanding Options, Options granted | shares

14,008,093

^[1]

Number of Shares Underlying Outstanding Options, Options exercised | shares

(215,067)

Number of Shares Underlying Outstanding Options, Options forfeited and cancelled | shares

(14,210,119)

^[1]

Number of Shares Underlying Outstanding Options, Options expired | shares

(14,729)

Number of Shares Underlying Outstanding Options, Ending Balance | shares

8,246,945

8,678,767

Number of Shares Underlying Outstanding Options, Exercisable- June 30, 2023 | shares

7,412,252

Weighted- Average Exercise Price

Weighted- Average Exercise Price, Beginning Balance | $ / shares

$ 1.42

Weighted- Average Exercise Price, Options granted | $ / shares

0.86

^[1]

Weighted- Average Exercise Price, Options Exercised | $ / shares

0.1

Weighted- Average Exercise Price, Options forfeited and cancelled | $ / shares

0.91

^[1]

Weighted- Average Exercise Price, Options expired | $ / shares

34.33

Weighted- Average Exercise Price, Ending Balance | $ / shares

1.32

$ 1.42

Weighted- Average Exercise Price, Exercisable - June 30, 2023 | $ / shares

$ 1.39

Weighted-Average Remaining Contractual Term (Years)

Weighted-Average Remaining Contractual Term (Years), Outstanding Balance

5 years 8 months 4 days

7 years 5 months 19 days

[1]	Includes options that were cancelled and re-granted as part of the option modification from the special cash dividend, as further discussed above.

Income Taxes

6 Months Ended

Jun. 30, 2023

Income Tax Disclosure [Abstract]

Income Taxes

During the three and six months ended June 30, 2023, the Company recorded an income tax expense of $2,000 and $16,000, respectively. No income tax expense was recognized during the three and six months ended June 30, 2022. The Company recorded no income tax benefits for the net operating losses incurred or for the research and development tax credits generated in each period due to its uncertainty of realizing a benefit from those items. All of the Company’s operating losses since inception have been generated in the United States.

As of June 30, 2023, after consideration of certain limitations (see below), the Company had approximately $193.8 million federal and $3.6 million state net operating loss carryforwards (“NOL”) available to reduce future taxable income which, if unused, the majority will carry forward indefinitely for federal and will begin to expire in 2034 for state tax purposes.

If the Company experiences a greater than 50 percent aggregate change in ownership over a three-year period (a Section 382 ownership change), utilization of its pre-change NOL carryforwards are subject to annual limitation under Section 382 of the Internal Revenue Code (California has similar provisions). The annual limitation is determined by multiplying the value of the Company's stock at the time of such ownership change by the applicable long-term tax-exempt rate. Such limitations may result in expiration of a portion of the NOL carryforwards before utilization. The Company determined that ownership changes occurred on December 31, 2007, August 20, 2015, April 13, 2017, February 15, 2018, February 18, 2020, and December 26, 2022. The ability of the Company to use its remaining NOL and tax credit carry forwards may be further limited if the Company experiences a Section 382 ownership change as a result of future changes in its stock ownership.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following tables present the fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of June 30, 2023 and December 31, 2022 (in thousands):


	June 30, 2023
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds(1)	$	6,923	$	—	$	—	$	6,923
Long-term receivable from GCBP		—		—		4,606		4,606
Total financial assets	$	6,923	$	—	$	4,606	$	11,529

Financial liabilities:
CVR derivative liability, noncurrent	$	—	$	—	$	4,606	$	4,606
Total financial liabilities	$	—	$	—	$	4,606	$	4,606


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds(1)	$	21,666	$	—	$	—	$	21,666
Total financial assets	$	21,666	$	—	$	—	$	21,666

Financial liabilities:
CVR derivative liability	$	—	$	—	$	5,000	$	5,000
Total financial liabilities	$	—	$	—	$	5,000	$	5,000

(1)

Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets.

Changes in Estimated Fair Value of Level 3 Financial Assets and Liabilities

The following table sets forth the changes in the estimated fair value of the Company’s Level 3 financial assets and liabilities (in thousands):


	Long-term receivable		CVR derivative
	from GCBP		liability, noncurrent
Balance at December 31, 2022	$	—	$	—
Additions in the period		4,530		4,530
Changes in fair value		76		76
Balance at June 30, 2023	$	4,606	$	4,606

Fair Value Measurements

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

For a description of the fair value hierarchy and the Company’s fair value methodology, see “Part II - Item 8 - Financial Statements and Supplementary Data - Note 3 – Summary of Significant Accounting Policies” in the Company’s Annual Report. There were no significant changes in these methodologies during the six months ended June 30, 2023.

The following tables present the fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of June 30, 2023 and December 31, 2022 (in thousands):


	June 30, 2023
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds(1)	$	6,923	$	—	$	—	$	6,923
Long-term receivable from GCBP		—		—		4,606		4,606
Total financial assets	$	6,923	$	—	$	4,606	$	11,529

Financial liabilities:
CVR derivative liability, noncurrent	$	—	$	—	$	4,606	$	4,606
Total financial liabilities	$	—	$	—	$	4,606	$	4,606


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds(1)	$	21,666	$	—	$	—	$	21,666
Total financial assets	$	21,666	$	—	$	—	$	21,666

Financial liabilities:
CVR derivative liability	$	—	$	—	$	5,000	$	5,000
Total financial liabilities	$	—	$	—	$	5,000	$	5,000

(1)

Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets.

The carrying amounts of accounts and other receivables, accounts payable, and accrued liabilities approximate their fair values due to the short-term maturity of these instruments.

Derivative Liabilities and Long-term Receivables

The CVR derivative liability relates to the CVR Agreement executed in connection with the Business Combination Agreement. The fair value of this derivative liability is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy. The estimated fair value of the CVR liability was determined based on the anticipated amount and timing of projected cash flows to be received from Vertex pursuant to the Vertex asset purchase agreement. The CVR liability was initially recorded at $5.0 million at issuance on December 26, 2022 and in May 2023, the Company received a $5.0 million hold-back payment from Vertex, which was distributed, net of expenses and a reserve for potential tax liabilities, to the holders of Catalyst common stock as of January 5, 2023 under the CVR Agreement. There was no change in the estimated fair value of the CVR liability during the six months ended June 30, 2023 prior to the distribution.

The long-term receivable and the corresponding CVR derivative liability, noncurrent relate to the asset purchase agreement with GCBP. The fair value of this long-term receivable and derivative liability is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy. The estimated fair value of the long-term receivable and CVR derivative liability, noncurrent was determined based on the anticipated amount and timing of projected cash flows to be received from GCBP pursuant to the GCBP asset purchase agreement discounted to their present values using an estimated discount rate of 5.05%. As of June 30, 2023, the Company expects to receive a $5.0 million hold-back payment from GCBP in the first quarter of 2025, which will be distributed, net of expenses, to the holders of Catalyst common stock as of January 5, 2023 under the CVR Agreement. The change in fair value of the long-term receivable from GCBP and the corresponding CVR derivative liability, noncurrent was recorded in interest and other income, net on the condensed consolidated statement of operations and comprehensive income (loss).

The following table sets forth the changes in the estimated fair value of the Company’s Level 3 financial assets and liabilities (in thousands):


	Long-term receivable		CVR derivative
	from GCBP		liability, noncurrent
Balance at December 31, 2022	$	—	$	—
Additions in the period		4,530		4,530
Changes in fair value		76		76
Balance at June 30, 2023	$	4,606	$	4,606

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Restructuring - Additional Information (Detail) $ in Thousands				1 Months Ended						3 Months Ended		6 Months Ended
	Jun. 05, 2023 USD ($)	Mar. 08, 2023 USD ($)	Jan. 12, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Feb. 28, 2023 USD ($)	May 31, 2022 USD ($)	Mar. 31, 2022 Employee	Nov. 30, 2021	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)
Restructuring Cost And Reserve [Line Items]
Percent of employees terminated									35.00%
Number of Employees terminated \| Employee								22
Remaining number of full time employees \| Employee								5
Proceeds from Sale of Intangible Assets												$ 1,000
Gain (loss) on disposal										$ 57,245		4,736	$ 57,245
Amount of dividend payment			$ 7,600
Contingent Value Rights Agreement
Restructuring Cost And Reserve [Line Items]
Distribution to CVR holders from asset sale proceeds	$ 3,500	$ 200			$ 200
Amount of dividend payment	$ 3,500	$ 200		$ 3,500
Vertex Pharmaceuticals Incorporated
Restructuring Cost And Reserve [Line Items]
Proceeds from Sale of Intangible Assets							$ 60,000
Upfront payment received							55,000
Post closing indemnification obligation							5,000
Gain (loss) on disposal							$ 57,400
Transaction costs										2,600
GCBP Asset Purchase Agreement
Restructuring Cost And Reserve [Line Items]
Proceeds from Sale of Intangible Assets						$ 6,000
Upfront payment received						1,000
Post closing indemnification obligation						5,000
Gain (loss) on disposal						$ 4,700
Transaction costs												$ 800
Dren Bio, Inc. and Copia Scientific, LLC
Restructuring Cost And Reserve [Line Items]
Total consideration for sales agreements										400			400
Gain (loss) on disposal										$ (200)			$ (200)
Operating Expense
Restructuring Cost And Reserve [Line Items]
Restructuring costs											$ 1,000

F351 Asset Acquisition

6 Months Ended

Jun. 30, 2023

Business Combinations [Abstract]

F351 Asset Acquisition

On December 26, 2022, the Company acquired the F351 Assets from GNI in accordance with the terms of the F351 Agreement as discussed in Note 1, Nature of Operations and Liquidity. Under the terms of the F351 Agreement, the Company issued 6,266,521 shares of common stock and 12,340 shares of Catalyst Convertible Preferred Stock.

The Company concluded that the F351 acquisition was not the acquisition of a business, as substantially all of the fair value of the gross assets acquired was concentrated in a single identifiable asset, the intellectual property rights (outside of China) to a clinical stage drug candidate for the treatment of liver fibrosis, or the F351 Assets.

Subject to stockholder approval, each share of Catalyst Convertible Preferred Stock issued under the F351 Agreement is convertible into 10,000 shares of common stock. The Company is required to hold a stockholders’ meeting to request the approval of the conversion of the Catalyst Convertible Preferred Stock into shares of common stock in accordance with Nasdaq Listing Rule 5635(a) (the “Conversion Proposal”). The Company expects to hold its 2023 Annual Meeting of Stockholders on August 29, 2023 and will include the following matters as proposals to be voted on at the meeting: (i) the Conversion Proposal and (ii) if necessary or appropriate, the approval of an amendment to the Company’s certificate of incorporation to authorize sufficient shares of common stock for the conversion of the Catalyst Convertible Preferred Stock issued pursuant to the F351 Agreement.

In March 2023, the Company amended the F351 Agreement and the Catalyst Convertible Preferred Stock Certificate of Designation to extend the deadline for the cash settlement of the Catalyst Convertible Preferred Stock from June 26, 2023 to September 30, 2023. Under the amended terms, if the Company’s stockholders do not approve the conversion of the Catalyst Convertible Preferred Stock by September 30, 2023, then the Catalyst Convertible Preferred Stock would be redeemable at the option of the holders for cash equal to the closing price of the common stock on the last trading day prior to the holder’s redemption request. Using the closing price on August 7, 2023 of $0.35, if all the currently outstanding Catalyst Convertible Preferred Stock was redeemed for cash, the Company would be required to make a payment of approximately $43.2 million. The Company has insufficient liquidity to make such a payment, if required.

F351 Asset Acquisition - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Dec. 26, 2022	Aug. 07, 2023
Subsequent Event [Member]
Asset Acquisition [Line Items]
Common stock closing price		$ 0.35
Conversion of outstanding preferred stock redeemed for cash		$ 43.2
F351 Agreement \| Convertible Preferred Stock
Asset Acquisition [Line Items]
Preferred stock shares issued	12,340
Preferred stock, shares issued upon conversion of common stock	10,000
Common Stock \| F351 Agreement
Asset Acquisition [Line Items]
Assets acquisition, shares issued	6,266,521

Nature of Operations and Liquidity

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Operations and Liquidity

Catalyst Biosciences, Inc. and its subsidiary (the “Company” or “Catalyst”) was a biopharmaceutical company with expertise in protease engineering. Prior to ceasing research and development activities in March 2022, the Company had several protease assets that were designed to address unmet medical needs in disorders of the complement or coagulation systems. As discussed below, the Company recently completed a purchase agreement to acquire a clinical-stage drug candidate for the treatment of NASH (nonalcoholic steatohepatitis, a severe form of nonalcoholic fatty liver disease). Concurrent with this purchase agreement, the Company entered into a separate business combination agreement to acquire an indirect controlling interest in a China-based pharmaceutical company. The Company is located in South San Francisco, California and operates in one segment.

On May 19, 2022, Catalyst entered into and closed on an asset purchase agreement with Vertex Pharmaceuticals Inc. (“Vertex”), pursuant to which Vertex acquired Catalyst’s complement portfolio, including CB 2782-PEG and CB 4332, as well as its complement-related intellectual property including the ProTUNETM and ImmunoTUNETM platforms. See Note 11, Restructuring.

On February 27, 2023, Catalyst entered into and closed on an asset purchase agreement with GC Biopharma Corp. (“GCBP”), pursuant to which GCBP acquired Catalyst’s legacy rare bleeding disorder program, including the coagulation related assets marzeptacog alfa (activated) (“MarzAA”), dalcinonacog alfa (“DalcA”), and CB-2679d-GT. See Note 11, Restructuring.

F351 Asset Acquisition

On December 26, 2022, the Company executed and closed an Asset Purchase Agreement, which was amended on March 29, 2023 (the “F351 Agreement”), with GNI Group Ltd. (“GNI Japan”) and GNI Hong Kong Limited to purchase all of the assets and intellectual property rights primarily related to the proprietary Hydronidone compound (collectively, the “F351 Assets”), other than such assets and intellectual property rights located in the People’s Republic of China. At the closing of the agreement on December 26, 2022, the Company paid $35.0 million in the form of 6,266,521 shares of Catalyst common stock and 12,340 shares of newly designated Series X redeemable convertible preferred stock (“Catalyst Convertible Preferred Stock”). Each share of Catalyst Convertible Preferred Stock is convertible into 10,000 shares of common stock, subject to stockholder approval under Nasdaq rules and subject to a beneficial ownership conversion blocker. For additional information, see Note 3, F351 Asset Acquisition.

Business Combination Agreement

Concurrent with the F351 Asset acquisition, the Company signed a definitive agreement, as amended on March 29, 2023, with GNI Group Ltd., GNI Hong Kong Limited, GNI USA, Inc., Continent Pharmaceuticals Inc. and Shanghai Genomics, Inc. (collectively, “GNI”) and other minority stockholders to acquire an indirect controlling interest in Beijing Continent Pharmaceutical Co Ltd. (“BC”), a commercial-stage pharmaceutical company based in China and majority-owned subsidiary of GNI, in exchange for newly issued shares of common stock (the “Business Combination Agreement”). The closing of the transactions under the Business Combination Agreement will be subject to stockholder approval at a stockholder meeting expected to be held on August 29, 2023 and certain customary closing conditions. For additional information, see Note 8, Commitments and Contingencies.

Contingent Value Rights Agreement

Pursuant to the Business Combination Agreement, on December 26, 2022, Catalyst and the Rights Agent (as defined therein) executed a contingent value rights agreement, as amended on March 29, 2023 (the “CVR Agreement”), pursuant to which each holder of Catalyst common stock as of January 5, 2023, excluding GNI (the “CVR Holders”), received one contractual contingent value right (a “CVR”) issued by the Company for each share of Catalyst common stock held by such holder. Each CVR entitles the holder thereof to receive certain cash payments in the future. For additional information, see Note 8, Commitments and Contingencies.

Liquidity

On January 12, 2023, the Company paid a one-time cash dividend of $0.24 per share to the Company’s common stockholders of record as of close of business on January 5, 2023, excluding GNI. The aggregate amount of the special dividend payment was approximately $7.6 million.

On March 8, 2023, the Company distributed the net cash proceeds received from the GCBP asset sale of $0.2 million, or $0.01 per share, to the CVR Holders. See Note 11, Restructuring, for additional information regarding this distribution.

On June 5, 2023, the Company distributed the net cash proceeds received from the Vertex hold-back amount of $3.5 million, or $0.11 per share, to the CVR Holders. See Note 11, Restructuring, for additional information regarding this distribution.

The Company had a net loss of $2.2 million for the six months ended June 30, 2023. As of June 30, 2023, the Company had an accumulated deficit of $413.1 million and cash and cash equivalents of $6.9 million. Its primary uses of cash are to fund operating expenses and general and administrative expenditures. As part of the F351 Agreement, the Company issued 12,340 shares of Catalyst Convertible Preferred Stock, which upon stockholder approval, will be converted to 123,400,000 shares of common stock, subject to applicable beneficial ownership limitations. The terms of the Catalyst Convertible Preferred Stock include a cash settlement feature which provide that, if the Company’s stockholders fail to approve the conversion of the Catalyst Convertible Preferred Stock by September 30, 2023, the Company could be required to make cash payments to the holders of Catalyst Convertible Preferred Stock significantly in excess of its current liquidity. The Company believes that stockholders who are entitled to vote on the conversion proposal at the Company’s 2023 Annual Meeting of Stockholders, which is expected to be held on August 29, 2023, will vote to approve the proposal. However, as the vote of the Company’s common stockholders is outside of the control of the Company, there is substantial doubt about its ability to continue as a going concern for at least 12 months following the issuance of these condensed consolidated financial statements. The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) (Parenthetical) - $ / shares				3 Months Ended	6 Months Ended
	Jun. 05, 2023	Mar. 08, 2023	Jan. 12, 2023	Mar. 31, 2023	Jun. 30, 2023
Cash dividends paid per common share			$ 0.24		$ 0.24
Contingent Value Rights Agreement
Cash dividends paid per common share	$ 0.11	$ 0.01		$ 0.01

Restructuring

6 Months Ended

Jun. 30, 2023

Restructuring and Related Activities [Abstract]

Restructuring

11.

Restructuring

In November 2021, the Board approved a restructuring of its business based on its decision to stop the clinical development of MarzAA and focus solely on its complement programs and protease medicines platform. The restructuring included a reduction-in-force whereby approximately 35% of employees were terminated.

In March 2022, the Board approved a further reduction of its workforce as part of its restructuring plan whereby 22 full-time employees were terminated. Following this reduction, the Company had five full-time employees remaining. During the quarter ended March 31, 2022, the Company recorded additional charges of $1.0 million for severance and other costs related to the reduction-in-force, recognized as an operating expense within the condensed consolidated statements of operations and comprehensive income (loss), which the Company paid during the second quarter of 2022.

Sale of Assets

During the quarter ended June 30, 2022, the Company entered into sales agreements with Dren Bio, Inc. and Copia Scientific, LLC, pursuant to which the Company sold various lab equipment, consumables, and furniture and fixtures for a total consideration of $0.4 million. The Company recorded a loss on disposal of $0.2 million during the three and six months ended June 30, 2022, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss).

In May 2022, the Company entered into an asset purchase agreement with Vertex, pursuant to which Vertex purchased the Company’s complement portfolio, including CB 2782-PEG and CB 4332, as well as its complement-related intellectual property including the ProTUNETM and ImmunoTUNETM platforms for $60.0 million in cash consideration. Cash of $55.0 million was received upfront in May 2022 and the remaining $5.0 million was received in May 2023 upon satisfaction of certain post-closing indemnification obligations. The hold-back amount was initially recorded within accounts and other receivables on the condensed consolidated balance sheet. In June 2023, the Company distributed $3.5 million, which reflected the hold-back amount received

from Vertex less expenses and a reserve for potential tax liabilities, to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to Vertex, and, therefore, the Company recorded a gain of $57.4 million related to the disposal, net of $2.6 million of transaction costs during the second quarter of 2022.

In February 2023, Catalyst entered into an asset purchase agreement with GCBP, pursuant to which GCBP acquired the Company’s legacy rare bleeding disorders programs, including MarzAA, DalcA and CB-2679d-GT, for $6.0 million in cash consideration. Cash of $1.0 million was received upfront in February 2023 and the remaining $5.0 million will be paid two years after the closing upon satisfaction of certain post-closing indemnification obligations. The hold-back amount is recorded as a long-term receivable on the condensed consolidated balance sheet. In March 2023, the Company distributed the net cash proceeds received upfront of $0.2 million to the CVR Holders. Once received, the remaining net proceeds, net of expenses, from the hold-back amount will be distributed to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to GCBP, and, therefore, Catalyst recorded a gain of $4.7 million related to the disposal, net of $0.8 million of transaction costs, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss) for the six months ended June 30, 2023.

Stock Based Compensation - Summary of Stock-Based Compensation Expense Recognized (Parenthetical) (Detail)	6 Months Ended
	Jun. 30, 2023 shares
Share-Based Payment Arrangement [Abstract]
Number of shares of common stock issued to certain board members in lieu of cash compensation	0

Lease (Tables)

6 Months Ended

Jun. 30, 2023

Lessee Disclosure [Abstract]

Summary of Present Value Assumptions used in Calculating Present Value of Lease Payments

The present value assumptions used in calculating the present value of the lease payments were as follows:


	June 30, 2023	December 31, 2022
Weighted-average remaining lease term	n/a	0.3 years
Weighted-average discount rate	n/a		4.3	%

Schedule of Supplemental Cash Flow Information

Supplemental cash flow information related to operating leases was as follows (in thousands):


	Six Months Ended June 30,
	2023		2022
Cash paid for amounts included in the measurement of lease liabilities	$	39	$	1,015

Leases

6 Months Ended

Jun. 30, 2023

Lessee Disclosure [Abstract]

Lease

The Company leased office space for its corporate headquarters, located in South San Francisco, CA. The lease term expired on April 30, 2023. The Company currently has a month-to-month lease for its corporate headquarters.

In March 2022, the Company entered into a sublease agreement for its leased facility that commenced in April 2022. Under the terms of the sublease agreement, the Company received $0.2 million in base lease payments over the term of the sublease, which ended in April 2023. For the three and six months ended June 30, 2023, the Company recognized sublease income of $13,000 and $0.1 million, respectively. For the three and six months ended June 30, 2022, the Company recognized sublease income of $38,000.

For the three and six months ended June 30, 2023, the Company’s operating lease expense was $17,000 and $0.1 million, respectively. For the three and six months ended June 30, 2022, the Company’s operating lease expense was $0.6 million and $1.1 million, respectively.

Since the operating lease expired on April 30, 2023, the present value assumptions for the current period were not applicable. The present value assumptions used in calculating the present value of the lease payments were as follows:


	June 30, 2023	December 31, 2022
Weighted-average remaining lease term	n/a	0.3 years
Weighted-average discount rate	n/a		4.3	%

Supplemental cash flow information related to operating leases was as follows (in thousands):


	Six Months Ended June 30,
	2023		2022
Cash paid for amounts included in the measurement of lease liabilities	$	39	$	1,015

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating expenses (income):
Research and development	$ 318,000	$ 1,871,000	$ 906,000	$ 11,574,000
General and administrative	2,225,000	3,844,000	6,195,000	8,838,000
Gain on disposal of assets, net		(57,245,000)	(4,736,000)	(57,245,000)
Total operating expenses (income)	2,543,000	(51,530,000)	2,365,000	(36,035,000)
Income (loss) from operations	(2,543,000)	51,530,000	(2,365,000)	36,829,000
Interest and other income, net	73,000	102,000	169,000	267,000
Income (loss) before income taxes	(2,470,000)	51,632,000	(2,196,000)	37,096,000
Income tax expenses	2,000	0	16,000	0
Net income (loss) and comprehensive income (loss)	$ (2,472,000)	$ 51,632,000	$ (2,212,000)	$ 37,096,000
Net income (loss) per share attributable to common stockholders, basic	$ (0.07)	$ 1.64	$ (0.06)	$ 1.18
Net income (loss) per share attributable to common stockholders, diluted	$ (0.07)	$ 1.64	$ (0.06)	$ 1.18
Shares used to compute net income (loss) per share attributable to common stockholders, basic	37,800,121	31,477,053	37,779,384	31,466,630
Shares used to compute net income (loss) per share attributable to common stockholders, diluted	37,800,121	31,482,925	37,779,384	31,469,566
Cash dividends paid per common share			$ 0.24
Contingent Value Rights Agreement
Operating expenses (income):
Cash dividends paid per common share	$ 0.11		$ 0.12
Collaboration
Revenue:
License and collaboration revenue				$ 794,000
Cost of collaboration
Operating expenses (income):
Cost of license and collaboration				$ 798,000

Net Income (Loss) per Share Attributable to Common Stockholders - Anti-dilutive Security not Included In Diluted per Share Calculations (Detail) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive securities	8,246,945	2,512,163
Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive securities	8,246,945	2,512,078
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive securities		85

Stock Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Option Activity Under Company's Equity Incentive Plans

The following table summarizes stock option activity under the Company’s 2018 Plan and related information:


	Number of Shares Underlying Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)
Outstanding — December 31, 2022		8,678,767		$	1.42		7.47
Options granted (1)		14,008,093		$	0.86
Options exercised		(215,067	)	$	0.10
Options forfeited and cancelled (1)		(14,210,119	)	$	0.91
Options expired		(14,729	)	$	34.33
Outstanding — June 30, 2023		8,246,945		$	1.32		5.68
Exercisable — June 30, 2023		7,412,252		$	1.39

(1)

Includes options that were cancelled and re-granted as part of the option modification from the special cash dividend, as further discussed above.

Summary of Weighted Average Valuation Assumptions Used to Estimate Fair Value of Employee Stock Options

The fair value of employee stock options was estimated using the following weighted-average assumptions:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023	2022			2023	2022
Employee Stock Options:
Risk-free interest rate	n/a		2.93	%	n/a		2.22	%
Expected term (in years)	n/a		6.0		n/a		6.0
Dividend yield	n/a		—		n/a		—
Volatility	n/a		91.82	%	n/a		91.63	%
Weighted-average fair value of stock options granted	n/a	$	0.87		n/a	$	0.55

Summary of Stock-Based Compensation Expense Recognized

Total stock-based compensation expense recognized was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	1	$	83	$	67	$	211
General and administrative(1)		88		263		232		650
Total stock-based compensation expense	$	89	$	346	$	299	$	861

(1)

No shares of common stock were issued to Board members for the three and six months ended June 30, 2023.

Related Parties - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 26, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Apr. 18, 2023
Related Party Transaction [Line Items]
Development costs		$ 318	$ 1,871	$ 906	$ 11,574
GNI
Related Party Transaction [Line Items]
Percentage of convertible preferred stock owned	100.00%
Percentage of common stock outstanding				16.50%		16.60%
Percentage of outstanding shares of capital stock				80.40%		80.50%
Minimum percentage of director to stockholder of the company				5.00%
Non GMP Manufacturing Services
Related Party Transaction [Line Items]
Cost of services as per agreement		300		$ 300			$ 300
Development costs		300
Non GMP Manufacturing Services \| Related Party \| Prepaid and Other Current Assets
Related Party Transaction [Line Items]
Amounts receivable from related party		$ 300		$ 300

Stock Based Compensation - Fair Values of Stock Options Estimated Using Black-Scholes Valuation Model (Detail) - Employee Stock Option - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Black Scholes Method Used [Line Items]
Risk-free interest rate	2.93%	2.22%
Expected term (in years)	6 years	6 years
Dividend yield	0.00%	0.00%
Volatility	91.82%	91.63%
Weighted-average fair value of stock options granted	$ 0.87	$ 0.55

Stock Based Compensation - Summary of Stock-Based Compensation Expense Recognized (Detail) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2023

Jun. 30, 2022

Jun. 30, 2023

Jun. 30, 2022

Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]

Total stock-based compensation

$ 89

$ 346

$ 299

$ 861

Research and development

Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]

Total stock-based compensation

211

General and Administrative

Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]

Total stock-based compensation

^[1]

$ 88

$ 263

$ 232

$ 650

[1]	No shares of common stock were issued to Board members for the three and six months ended June 30, 2023.

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Detail) - USD ($)
$ in Thousands

Jun. 30, 2023

Dec. 31, 2022

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

$ 11,529

$ 21,666

Liabilities, fair value

4,606

5,000

Long-term receivable

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

4,606

Money Market Funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

^[1]

6,923

21,666

CVR Derivative Liability

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Liabilities, fair value

5,000

CVR Derivative Liability non current

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Liabilities, fair value

4,606

Fair Value, Inputs, Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

6,923

21,666

Fair Value, Inputs, Level 1 | Money Market Funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

^[1]

6,923

21,666

Fair Value, Inputs, Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

4,606

Liabilities, fair value

4,606

5,000

Fair Value, Inputs, Level 3 | Long-term receivable

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets, fair value

4,606

Fair Value, Inputs, Level 3 | CVR Derivative Liability

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Liabilities, fair value

$ 5,000

Fair Value, Inputs, Level 3 | CVR Derivative Liability non current

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Liabilities, fair value

$ 4,606

[1]	Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets.

Nature of Operations and Liquidity - Additional Information (Detail) $ / shares in Units, $ in Thousands					1 Months Ended	3 Months Ended				6 Months Ended
	Jun. 05, 2023 USD ($) $ / shares	Mar. 08, 2023 USD ($) $ / shares	Jan. 12, 2023 USD ($) $ / shares	Dec. 26, 2022 USD ($) shares	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2023 USD ($) Segment $ / shares	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Organization and Nature of Operations [Line Items]
Number of operating segment \| Segment										1
Dividends Payable, date declared			Jan. 12, 2023
Dividends paid \| $ / shares			$ 0.24							$ 0.24
Amount of dividend payment			$ 7,600
Common stock, dividend payable, date of record			Jan. 05, 2023
Net income (loss)						$ (2,472)	$ 260	$ 51,632	$ (14,536)	$ (2,212)	$ 37,096
Accumulated deficit					$ 413,148	413,148				413,148		$ 410,936
Cash and cash equivalents					6,923	$ 6,923				$ 6,923		$ 21,666
F351 Agreement
Organization and Nature of Operations [Line Items]
Assets acquisition, paid				$ 35,000
Purchase agreement amendment date				Mar. 29, 2023
Business Combination Agreement
Organization and Nature of Operations [Line Items]
Purchase agreement amendment date				Mar. 29, 2023
Contingent Value Rights Agreement
Organization and Nature of Operations [Line Items]
Purchase agreement amendment date				Mar. 29, 2023
Dividends paid \| $ / shares	$ 0.11	$ 0.01					$ 0.01
Amount of dividend payment	$ 3,500	$ 200			$ 3,500
Convertible Preferred Stock \| F351 Agreement
Organization and Nature of Operations [Line Items]
Preferred stock shares issued \| shares				12,340
Preferred stock, shares issued upon conversion of common stock \| shares				10,000
Common Stock \| F351 Agreement
Organization and Nature of Operations [Line Items]
Assets acquisition, shares issued \| shares				6,266,521
Conversion of stock shares, issued \| shares				123,400,000

Lease - Summary of Present Value Assumptions used in Calculating Present Value of Lease Payments (Detail)	Dec. 31, 2022
Lessee Disclosure [Abstract]
Weighted-average remaining lease term	3 months 18 days
Weighted-average discount rate	4.30%

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 6,923	$ 21,666
Accounts and other receivables		5,000
Prepaid and other current assets	697	1,540
Total current assets	7,620	28,206
Other assets, noncurrent	168	168
Right-of-use assets		66
Property and equipment, net		4
Total assets	12,394	28,444
Current liabilities:
Accounts payable	5	194
Accrued compensation	720	2,582
Other accrued liabilities	2,068	1,452
Dividends payable		7,558
CVR derivative liability		5,000
Operating lease liability		38
Total current liabilities	2,793	16,824
CVR derivative liability, noncurrent	4,606
Total liabilities	7,399	16,824
Commitments and Contingencies (Note 9)
Stockholders’ deficit:
Common stock, $0.001 par value, 100,000,000 shares authorized; 37,974,892 and 37,756,574 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively	37	37
Additional paid-in capital	384,797	389,210
Accumulated deficit	(413,148)	(410,936)
Total stockholders’ deficit	(28,314)	(21,689)
Total liabilities, redeemable convertible and redeemable preferred stock, and stockholders' deficit	12,394	28,444
Redeemable Convertible Preferred Stock
Current liabilities:
Redeemable preferred stock	33,309	33,309
Redeemable Preferred Stock
Current liabilities:
Redeemable preferred stock	0	$ 0
GC Biopharma Corp
Current assets:
Long-term receivable from GCBP	$ 4,606

Stock Based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock Based Compensation

2018 Omnibus Incentive Plan

In June 2018, stockholders of the Company approved the Company’s 2018 Omnibus Incentive Plan (the “2018 Plan”). The 2018 Plan had previously been approved by the Company’s Board of Directors (the “Board”) and the Compensation Committee (the “Committee”) of the Board, subject to stockholder approval. The 2018 Plan became effective on June 13, 2018. On June 9, 2021, the stockholders of the Company approved an amendment previously approved by the Board to increase the number of shares of common stock reserved for issuance under the 2018 Plan by 2,500,000 to a total of 5,300,000 shares. The amendment became effective immediately upon stockholder approval. After the option modification (as discussed below), the number of shares of common stock reserved for issuance under the 2018 Plan increased to a total of 31,456,403. As of June 30, 2023, there were 25,521,867 shares of common stock available for future grant.

Performance-Based Stock Option Grants

In June 2022, the Committee approved the issuance of an option grant to purchase 400,000 shares (2,457,917 shares after the option modification discussed below) of common stock to the Chief Executive Officer pursuant to the 2018 Plan, which will vest upon (a) the achievement of a specified performance goal and (b) the grantee’s continued employment during the service period. During the three months ended March 31, 2023, this award was cancelled. Prior to cancellation, no expense has been recognized related to this award and no options have vested.

Special Cash Dividend

On January 12, 2023, the Company paid a special, one-time cash dividend of $7.6 million (or $0.24 per share) to the Company’s common stockholders of record as of the close of business on January 5, 2023. The Company determined, in accordance with the adjustment provision of the 2018 Plan, that the special cash dividend was unusual and non-recurring and that appropriate adjustment to the stock options to purchase shares of the Company’s common stock outstanding under the 2018 Plan was required. The Company treated this adjustment as a modification to the original stock option grants because the terms of the agreements were modified in order to preserve the value of the option awards after a large non-recurring cash dividend. These options were amended to decrease the exercise price and increase the number of shares subject to the stock option on a proportionate basis. No incremental value was provided to the option holders as a result of the modification and no additional compensation cost was recorded by the Company.

The following table summarizes stock option activity under the Company’s 2018 Plan and related information:


	Number of Shares Underlying Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)
Outstanding — December 31, 2022		8,678,767		$	1.42		7.47
Options granted (1)		14,008,093		$	0.86
Options exercised		(215,067	)	$	0.10
Options forfeited and cancelled (1)		(14,210,119	)	$	0.91
Options expired		(14,729	)	$	34.33
Outstanding — June 30, 2023		8,246,945		$	1.32		5.68
Exercisable — June 30, 2023		7,412,252		$	1.39

(1)

Includes options that were cancelled and re-granted as part of the option modification from the special cash dividend, as further discussed above.

Valuation Assumptions

The Company estimated the fair value of stock options granted using the Black-Scholes option-pricing formula and a single option award approach. Due to its limited relevant historical data, the Company estimated its volatility considering a number of factors including the use of the volatility of comparable public companies. The expected term of options granted under the Plan, all of which qualify as “plain vanilla” per SEC Staff Accounting Bulletin 107, is determined based on the simplified method due to the Company’s limited relevant history. The risk-free rate is based on the yield of a U.S. Treasury security with a term consistent with the option. This fair value is being amortized ratably over the requisite service periods of the awards, which is generally the vesting period.

The only options granted during the six months ended June 30, 2023 were as a result of the option modification. Since no new stock options were granted during the three and six months ended June 30, 2023, all weighted-average assumptions for the period were not applicable.

The fair value of employee stock options was estimated using the following weighted-average assumptions:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023	2022			2023	2022
Employee Stock Options:
Risk-free interest rate	n/a		2.93	%	n/a		2.22	%
Expected term (in years)	n/a		6.0		n/a		6.0
Dividend yield	n/a		—		n/a		—
Volatility	n/a		91.82	%	n/a		91.63	%
Weighted-average fair value of stock options granted	n/a	$	0.87		n/a	$	0.55

Total stock-based compensation expense recognized was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	1	$	83	$	67	$	211
General and administrative(1)		88		263		232		650
Total stock-based compensation expense	$	89	$	346	$	299	$	861

(1)

No shares of common stock were issued to Board members for the three and six months ended June 30, 2023.

Condensed Consolidated Financial Statements Detail

6 Months Ended

Jun. 30, 2023

Condensed Financial Information Disclosure [Abstract]

Condensed Consolidated Financial Statements Detail

13.

Condensed Consolidated Financial Statements Detail

Other Accrued Liabilities

Other accrued liabilities consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Tax liability	$	1,500	$	—
Professional and consulting services		210		1,417
Manufacturing		87		22
Other		271		13
Total other accrued liabilities	$	2,068	$	1,452

Stockholders' Equity (Deficit) - Additional Information (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2023	Jun. 20, 2023
Stockholders Equity Disclosure [Line Items]
Preferred stock shares authorized	5,000,000
Preferred stock par value per share	$ 0.001
Redeemable Convertible Preferred Stock
Stockholders Equity Disclosure [Line Items]
Preferred stock shares authorized	123,418
Series Y Redeemable Preferred Stock
Stockholders Equity Disclosure [Line Items]
Preferred stock shares authorized	161,160
Preferred stock, voting rights	250,000 votes per share
Preferred stock redemption price per share	$ 0.001
Series Y Redeemable Preferred Stock \| One One-Thousandth Share Dividend Declared
Stockholders Equity Disclosure [Line Items]
Dividend declared, per share		$ 0.001

Summary of Significant Accounting Policies - Additional Information (Detail) - ASU 2016-13	Jun. 30, 2023
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2023
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true

- Definition

Indicates (true false) whether accounting standards update was adopted.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Date accounting standards update was adopted, in YYYY-MM-DD format.

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+ Details

Commitments and Contingencies - Additional Information (Detail)				1 Months Ended	6 Months Ended
	Jun. 05, 2023 USD ($)	Apr. 18, 2023 USD ($) Agreement	Mar. 08, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2023 USD ($) shares	Feb. 28, 2023 USD ($)	Dec. 31, 2022 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Long-term CVR derivative liability					$ 4,606,000
Number of separate agreements \| Agreement		2
Non GMP Manufacturing Services
Commitments And Contingencies Disclosure [Line Items]
Cost of services as per agreement		$ 300,000			$ 300,000
Clinical Supply Batch GMP Manufacturing
Commitments And Contingencies Disclosure [Line Items]
Cost of services as per agreement		$ 200,000
Contingent Value Rights Agreement
Commitments And Contingencies Disclosure [Line Items]
Percentage of excess cash on dispositions net					100.00%
Percentage of excess cash on dispositions net					$ 1,000,000
Percentage of excess preapproved costs					100.00%
Short-term CVR derivative liability							$ 5,000,000
Long-term CVR derivative liability						$ 4,500,000
Distribution to CVR holders from asset sale proceeds	$ 3,500,000		$ 200,000	$ 200,000
Vertex Asset Purchase Agreement \| Contingent Value Rights Agreement
Commitments And Contingencies Disclosure [Line Items]
Percentage of amount received on agreement, net of expenses					100.00%
F351 \| GNI \| Business Combination Agreement
Commitments And Contingencies Disclosure [Line Items]
Termination fee required to pay upon termination of agreement					$ 2,000,000.0
F351 \| GNI \| Maximum \| Business Combination Agreement
Commitments And Contingencies Disclosure [Line Items]
Common stock, shares issued \| shares					1,110,776,224
Reimbursement for out-of-pocket fees and expenses					$ 2,000,000.0

Commitments and Contingencies

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

As of June 30, 2023 and December 31, 2022, the Company had cash deposited in certain financial institutions in excess of federally insured levels. The Company regularly monitors the financial stability of these financial institutions and believes that it is not exposed to any significant credit risk in cash and cash equivalents. However, in March and April 2023, certain U.S. government banking regulators took steps to intervene in the operations of certain financial institutions due to liquidity concerns, which caused general heightened uncertainties in financial markets. While these events have not had a material direct impact on the Company’s operations, if further liquidity and financial stability concerns arise with respect to banks and financial institutions, either nationally or in specific regions, the Company’s ability to access cash or enter into new financing arrangements may be threatened, which could have a material adverse effect on its business, financial condition and results of operations.

Business Combination Agreement

Concurrent with the F351 Asset acquisition, as amended on March 29, 2023, the Company entered into the Business Combination Agreement with GNI and other minority stockholders (“Sellers” and each a “Seller”) to acquire an indirect controlling interest in BC, a commercial-stage pharmaceutical company based in China and majority-owned subsidiary of GNI, in exchange for newly issued shares of Catalyst common stock. The closing of the transactions under the Business Combination Agreement will be subject to stockholder approval at a stockholder meeting expected to be held on August 29, 2023 and certain customary closing conditions. If the transaction is approved by stockholders, the Company would issue at closing a total of up to 1,110,776,224 shares of Catalyst common stock for an indirect controlling interest in BC. Each Seller may elect to be issued Catalyst Convertible Preferred Stock in lieu of the Company’s common stock.

The Business Combination Agreement contains certain termination rights, including the right for Catalyst to terminate the Business Combination Agreement to enter into a definitive agreement for a superior proposal. Upon termination of the Business Combination Agreement under specified circumstances, the Company may be required to pay a termination fee of $2.0 million and either party, as the case may be, may be required to reimburse the other party for reasonable out-of-pocket fees and expenses incurred by such party in connection with the Business Combination Agreement, up to a maximum amount of $2.0 million.

Contingent Value Rights Agreement

Pursuant to the Business Combination Agreement, on December 26, 2022, Catalyst and the Rights Agent (as defined therein) executed the CVR Agreement, as amended on March 29, 2023, pursuant to which the CVR Holders received one contractual CVR issued by the Company, subject to and in accordance with the terms and conditions of the CVR Agreement, for each share of Catalyst common stock held by such holder. Each CVR entitles the holder thereof to receive (i) certain cash payments from the net proceeds related to the disposition of the Company’s legacy assets (MarzAA, DalcA, and CB 2679d-GT), (ii) 100% of the excess cash (net of all current or contingent liabilities, including transaction-related expenses) retained by the Company in excess of $1.0 million as of the closing date of the transactions under the Business Combination Agreement, (iii) 100% of the amount actually received by the Company, net of expenses, pursuant to the Vertex asset purchase agreement and (iv) 100% of the excess, by which the preapproved costs to manage, negotiate, settle and finalize certain third party claims exceed the costs actually incurred with respect to such claims. The CVRs are not transferable, except in certain limited circumstances as provided for in the CVR Agreement, will not be certificated or evidenced by any instrument, and will not be registered with the SEC or listed for trading on any exchange.

In December 2022, the Company recorded a $5.0 million short-term CVR derivative liability related to the Vertex asset purchase agreement. On June 5, 2023, the Company distributed the net cash proceeds received from Vertex of $3.5 million, which reflected the amount received from Vertex less expenses and a reserve for potential tax liabilities, to the CVR Holders. Refer to Note 4, Fair Value Measurements and Note 11, Restructuring, for additional information regarding the CVR derivative liability and Vertex hold-back payment.

In February 2023, the Company recorded a $4.5 million long-term CVR derivative liability as a result of the disposition of the Company’s legacy assets to GCBP. On March 8, 2023, the Company distributed the net cash proceeds received from the GCBP asset sale of $0.2 million to the CVR Holders. Refer to Note 4, Fair Value Measurements and Note 11, Restructuring, for additional information regarding the CVR derivative liability and GCBP asset sale.

Manufacturing Agreements

On April 18, 2023, the Company entered into two separate agreements to support the F351 Assets acquired from GNI. One agreement will cover analytical method process familiarization and validation to support good manufacturing practices (“GMP”) manufacturing, and the other agreement will cover non-GMP manufacturing services and clinical supply batch GMP manufacturing of the F351 Assets, with total payments of up to $0.3 million and $0.2 million, respectively. The Company can terminate these agreements at any time upon 90 days written notice. Upon termination, the Company will be responsible to pay for services incurred prior to termination and any non-cancellable obligations in connection with such services.

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax [Line Items]
Income tax expense (benefits)	$ 2,000	$ 0	$ 16,000	$ 0
Research and Development Tax Credits
Income Tax [Line Items]
Income tax expense (benefits)			0
Federal Income Tax
Income Tax [Line Items]
Net operating loss carryforwards	193,800,000		193,800,000
State Income Tax
Income Tax [Line Items]
Net operating loss carryforwards	$ 3,600,000		$ 3,600,000
Net operating loss carryforwards expiration year			2034

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Stock Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	6 Months Ended
	Jan. 12, 2023	Jun. 09, 2021	Mar. 31, 2023	Jun. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock available for future grant				25,521,867
Options vested			0
Aggregate amount of special dividend payment	$ 7.6
Dividends paid	$ 0.24			$ 0.24
Dividends Payable, date declared	Jan. 12, 2023
Common stock, dividend payable, date of record	Jan. 05, 2023
Stock options granted during quarter				0
2018 Omnibus Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock reserved for issuance		2,500,000
Common stock, capital shares reserved for future issuance		5,300,000		31,456,403
2018 Omnibus Incentive Plan \| Performance Based Stock Option Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of option grants to purchase common stock shares				400,000
2018 Omnibus Incentive Plan \| Accounting Standards Update 2021-04 \| Performance Based Stock Option Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of option grants to purchase common stock shares				2,457,917

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and following the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the Company’s financial information. These interim results and cash flows for any interim period are not necessarily indicative of the results to be expected for the year ending December 31, 2023, or for any other future annual or interim period. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the consolidated financial statements filed with the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 (the “Annual Report”). Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, allowance of doubtful accounts, long-term receivable, CVR derivative liabilities, operating lease right-of-use assets and liabilities, accrued expenses, income taxes and stock-based compensation. The Company bases its estimates on various assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates. Accounting Pronouncements Recently Adopted In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments. The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about an entity's expected credit losses on financial instruments and other commitments to extend credit at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology currently used today with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to develop credit loss estimates. ASU 2016-13 is effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, using a modified retrospective approach. The Company adopted ASU 2016-13 and related updates as of January 1, 2023 and the adoption did not have a material impact on its condensed consolidated financial statements. Long-Term Receivable The Company determined that the hold-back from the GCBP asset sale in February 2023 qualified as a long-term receivable. The receivable is considered a loan held for investment since the Company has the intent and ability to hold to maturity. Catalyst has elected to account for the receivable under the fair value option method of accounting and any changes in fair value are recorded in interest and other income, net on the condensed consolidated statement of operations and comprehensive income (loss). Refer to Note 4, Fair Value Measurements and Note 11, Restructuring, for additional information regarding the long-term receivable and GCBP asset sale. Net Income (Loss) per Share Attributable to Common Stockholders The Company calculates basic and diluted net income (loss) per share attributable to common stockholders in conformity with the two-class method required for participating securities. The Catalyst Convertible Preferred Stock contractually entitles the holders of such shares to participate in dividends but such participation is contingent upon the completion of the merger with GNI. As a result, the Catalyst Convertible Preferred Stock is excluded from the basic EPS calculation, as these shares are not participating securities until the merger with GNI closes. As such, net income for the periods presented was not allocated to these securities. During periods of loss, the Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Participating securities are excluded from the basic weighted average common shares outstanding. Diluted net income (loss) per share attributable to common stockholders is based on the weighted average number of common shares outstanding during the period, including potential dilutive common shares. For purposes of this calculation, outstanding stock options and warrants are considered potential dilutive common shares. The calculation of diluted EPS does not consider the effect of the Catalyst Convertible Preferred Stock since conversion is contingent upon the occurrence of a specified future event.

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and following the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the Company’s financial information. These interim results and cash flows for any interim period are not necessarily indicative of the results to be expected for the year ending December 31, 2023, or for any other future annual or interim period. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the consolidated financial statements filed with the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 (the “Annual Report”).
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, allowance of doubtful accounts, long-term receivable, CVR derivative liabilities, operating lease right-of-use assets and liabilities, accrued expenses, income taxes and stock-based compensation. The Company bases its estimates on various assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Accounting Pronouncements Recently Adopted	Accounting Pronouncements Recently Adopted In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments. The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about an entity's expected credit losses on financial instruments and other commitments to extend credit at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology currently used today with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to develop credit loss estimates. ASU 2016-13 is effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, using a modified retrospective approach. The Company adopted ASU 2016-13 and related updates as of January 1, 2023 and the adoption did not have a material impact on its condensed consolidated financial statements.
Long-Term Receivable	Long-Term Receivable The Company determined that the hold-back from the GCBP asset sale in February 2023 qualified as a long-term receivable. The receivable is considered a loan held for investment since the Company has the intent and ability to hold to maturity. Catalyst has elected to account for the receivable under the fair value option method of accounting and any changes in fair value are recorded in interest and other income, net on the condensed consolidated statement of operations and comprehensive income (loss). Refer to Note 4, Fair Value Measurements and Note 11, Restructuring, for additional information regarding the long-term receivable and GCBP asset sale.
Net Income (Loss) per Share Attributable to Common Stockholders	Net Income (Loss) per Share Attributable to Common Stockholders The Company calculates basic and diluted net income (loss) per share attributable to common stockholders in conformity with the two-class method required for participating securities. The Catalyst Convertible Preferred Stock contractually entitles the holders of such shares to participate in dividends but such participation is contingent upon the completion of the merger with GNI. As a result, the Catalyst Convertible Preferred Stock is excluded from the basic EPS calculation, as these shares are not participating securities until the merger with GNI closes. As such, net income for the periods presented was not allocated to these securities. During periods of loss, the Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Participating securities are excluded from the basic weighted average common shares outstanding. Diluted net income (loss) per share attributable to common stockholders is based on the weighted average number of common shares outstanding during the period, including potential dilutive common shares. For purposes of this calculation, outstanding stock options and warrants are considered potential dilutive common shares. The calculation of diluted EPS does not consider the effect of the Catalyst Convertible Preferred Stock since conversion is contingent upon the occurrence of a specified future event.

Lease - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 39	$ 1,015

Related Parties

6 Months Ended

Jun. 30, 2023

Related Parties

12.

Related Parties

Following the closing of the F351 Agreement on December 26, 2022, GNI owned 100% of the Catalyst Convertible Preferred Stock as well as 16.6% and 16.5% of Catalyst common stock outstanding as of December 31, 2022 and June 30, 2023, respectively. Overall, GNI owned 80.5% and 80.4% of the outstanding shares of capital stock of the Company, on an as converted basis, as of December 31, 2022 and June 30, 2023, respectively. In addition, Ying Luo and Thomas Eastling became directors of the Company. They serve as a director, representative executive officer, President and Chief Executive Officer, and an outside member, respectively, of GNI Japan, a greater than 5% stockholder of the Company. Dr. Luo also serves as a director of the board and President of GNI USA, Inc. GNI is considered a related party of the Company.

On April 13, 2023, the Company entered into a Cost Sharing and Agency Agreement with GNI. Under the Cost Sharing and Agency agreement, GNI will pay for certain costs related to the development of the F351 Assets in the U.S. incurred from December 26, 2022 until the Business Combination Agreement closes. Following the closing of the Business Combination Agreement, the Company will be required to reimburse GNI for such costs. During the three and six months ended June 30, 2023, the costs incurred for the development of the F351 Assets under the Cost Sharing and Agency Agreement was approximately $0.3 million. The Company paid $0.3 million of development costs related to the F351 Assets during the three months ended June 30, 2023 and GNI has agreed to repay Catalyst for such costs in its next payment cycle. As of June 30, 2023, the Company had amounts receivable from this related party of $0.3 million which was included in prepaid and other current assets on the balance sheet.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Condensed Consolidated Financial Statements Detail (Tables)

6 Months Ended

Jun. 30, 2023

Condensed Financial Information Disclosure [Abstract]

Schedule of Other Accrued Liabilities

Other accrued liabilities consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Tax liability	$	1,500	$	—
Professional and consulting services		210		1,417
Manufacturing		87		22
Other		271		13
Total other accrued liabilities	$	2,068	$	1,452

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock	Redeemable Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Balance at Dec. 31, 2021	$ 41,089			$ 31	$ 443,752	$ (402,694)
Balance (in shares) at Dec. 31, 2021				31,409,707
Stock-based compensation expense	515				515
Stock-based compensation expense, shares				32,684
Issuance of common stock from stock grants	16				16
Issuance of common stock from stock grants, shares				34,662
Net income (loss)	(14,536)					(14,536)
Balance at Mar. 31, 2022	27,084			$ 31	444,283	(417,230)
Balance (in shares) at Mar. 31, 2022				31,477,053
Balance at Dec. 31, 2021	41,089			$ 31	443,752	(402,694)
Balance (in shares) at Dec. 31, 2021				31,409,707
Net income (loss)	37,096
Balance at Jun. 30, 2022	79,062			$ 31	444,629	(365,598)
Balance (in shares) at Jun. 30, 2022				31,477,053
Balance at Mar. 31, 2022	27,084			$ 31	444,283	(417,230)
Balance (in shares) at Mar. 31, 2022				31,477,053
Stock-based compensation expense	346				346
Net income (loss)	51,632					51,632
Balance at Jun. 30, 2022	79,062			$ 31	444,629	(365,598)
Balance (in shares) at Jun. 30, 2022				31,477,053
Balance at Dec. 31, 2022	(21,689)			$ 37	389,210	(410,936)
Temporary equity, Balance (in shares) at Dec. 31, 2022		12,340	0
Temporary equity, Balance at Dec. 31, 2022		$ 33,309	$ 0
Balance (in shares) at Dec. 31, 2022				37,756,574
Stock-based compensation expense	210				210
Issuance of common stock from stock grants	2				2
Issuance of common stock from stock grants, shares				3,251
CVR cash dividends paid related to GCBP Agreement ($0.01 per share)	(206)				(206)
CVR derivative liability	(4,530)				(4,530)
Net income (loss)	260					260
Balance at Mar. 31, 2023	(25,953)			$ 37	384,686	(410,676)
Temporary Equity, Balance (in shares) at Mar. 31, 2023		12,340
Temporary Equity, Balance at Mar. 31, 2023		$ 33,309
Balance (in shares) at Mar. 31, 2023				37,759,825
Balance at Dec. 31, 2022	$ (21,689)			$ 37	389,210	(410,936)
Temporary equity, Balance (in shares) at Dec. 31, 2022		12,340	0
Temporary equity, Balance at Dec. 31, 2022		$ 33,309	$ 0
Balance (in shares) at Dec. 31, 2022				37,756,574
Issuance of common stock from option exercises, shares	215,067
CVR derivative liability	$ (4,530)
Net income (loss)	(2,212)
Balance at Jun. 30, 2023	(28,314)			$ 37	384,797	(413,148)
Temporary Equity, Balance (in shares) at Jun. 30, 2023		12,340	37,975
Temporary Equity, Balance at Jun. 30, 2023		$ 33,309	$ 0
Balance (in shares) at Jun. 30, 2023				37,974,892
Balance at Mar. 31, 2023	(25,953)			$ 37	384,686	(410,676)
Temporary equity, Balance (in shares) at Mar. 31, 2023		12,340
Temporary equity, Balance at Mar. 31, 2023		$ 33,309
Balance (in shares) at Mar. 31, 2023				37,759,825
Stock-based compensation expense	89				89
Issuance of common stock from option exercises	22				22
Issuance of common stock from option exercises, shares				215,067
Issuance of preferred stock for stock dividends, shares			37,975
Net income (loss)	(2,472)					(2,472)
Balance at Jun. 30, 2023	$ (28,314)			$ 37	$ 384,797	$ (413,148)
Temporary Equity, Balance (in shares) at Jun. 30, 2023		12,340	37,975
Temporary Equity, Balance at Jun. 30, 2023		$ 33,309	$ 0
Balance (in shares) at Jun. 30, 2023				37,974,892

Net Income (Loss) per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Anti-dilutive Security not Included in Diluted per Share Calculations

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Six Months Ended June 30,
	2023		2022
Options to purchase common stock		8,246,945		2,512,078
Common stock warrants		—		85
Total		8,246,945		2,512,163

Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders


	Three Months Ended June 30,					Six Months Ended June 30,
	2023			2022		2023			2022
Numerator
Net income (loss)	$	(2,472	)	$	51,632	$	(2,212	)	$	37,096

Denominator
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, basic		37,800,121			31,477,053		37,779,384			31,466,630
Effect of dilutive stock options		—			5,872		—			2,936
Weighted-average number of shares used in computing net income (loss) per share available to common stockholders, diluted		37,800,121			31,482,925		37,779,384			31,469,566
Net income (loss) per share available for common stockholders, basic	$	(0.07	)	$	1.64	$	(0.06	)	$	1.18
Net income (loss) per share available for common stockholders, dilutive	$	(0.07	)	$	1.64	$	(0.06	)	$	1.18

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2023	Aug. 04, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	CBIO
Entity Registrant Name	Catalyst Biosciences, Inc.
Entity Central Index Key	0001124105
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		37,974,892
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	000-51173
Entity Tax Identification Number	56-2020050
Entity Address, Address Line One	611 Gateway Blvd.
Entity Address, Address Line Two	Suite 120
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	871-0761
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	37,974,892	37,756,574
Common stock, shares outstanding	37,974,892	37,756,574
Redeemable Convertible Preferred Stock
Temporary equity,par value	$ 0.001	$ 0.001
Temporary equity, shares authorized	123,418	123,418
Temporary equity, shares outstanding	12,340	12,340
Temporary equity, shares issued	12,340	12,340
Redeemable Preferred Stock
Temporary equity,par value	$ 0.001	$ 0.001
Temporary equity, shares authorized	161,160	0
Temporary equity, shares outstanding	37,975	0
Temporary equity, shares issued	37,975	0

Lease - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
Lease - Additional Information (Detail) - USD ($)	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lessee Lease Description [Line Items]
Lease expiration date				Apr. 30, 2023
Operating lease expense		$ 17,000	$ 600,000	$ 100,000	$ 1,100,000
Sublease Arrangement
Lessee Lease Description [Line Items]
Lease commencement month and year	2022-04
Lease expiration month and year	2023-04
Lease payments receivable	$ 200,000
Sublease Income		$ 13,000	$ 38,000	$ 100,000	$ 38,000

Condensed Consolidated Financial Statements Detail - Schedule of Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Tax liability	$ 1,500
Professional and consulting services	210	$ 1,417
Manufacturing	87	22
Other	271	13
Total other accrued liabilities	$ 2,068	$ 1,452

Stockholders' Equity (Deficit)

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Stockholders' Equity (Deficit)

10.

Stockholders’ Equity (Deficit)

The Company is authorized to issue 5,000,000 shares of preferred stock with a par value of $0.001 per share under its restated certificate of incorporation. The Company has designated 123,418 shares to be Catalyst Convertible Preferred Stock and in June 2023, designated 161,160 shares as Series Y redeemable preferred stock (“Series Y Preferred Stock”).

Redeemable Preferred Stock

On June 20, 2023, the Board declared a dividend of one one-thousandth of a share of Series Y Preferred Stock, par value $0.001 per share, for each outstanding share of common stock to stockholders of record as of June 30, 2023. This Series Y Preferred Stock entitles its holder to 250,000 votes per share exclusively on the vote for the proposal to approve the reverse stock split (as defined in the Series Y Preferred Stock Certificate of Designation). The Company expects to hold its 2023 Annual Meeting of Stockholders on August 29, 2023, which will include the reverse stock split as a proposal to be voted on at the meeting. All shares of Series Y Preferred Stock that are not present to vote on the reverse stock split will automatically be redeemed by the Company (the “Initial Redemption”). Any outstanding shares of Series Y Preferred Stock that have not been redeemed pursuant to an Initial Redemption will be redeemed in whole, but not in part, (i) if such redemption is ordered by the Board in its sole discretion, automatically and effective on such time and date specified by the Board in its sole discretion or (ii) automatically upon the effectiveness of the amendment to the certificate of incorporation implementing the reverse stock split. Each share of Series Y Preferred Stock will be redeemed at a redemption price of $0.001 per share. The holders of Series Y Preferred Stock are not entitled to receive dividends of any kind.

The Series Y Preferred Stock is classified as temporary equity on the condensed consolidated balance sheet because the shares contain redemption features that are not solely within the Company’s control. The Series Y Preferred Stock’s estimated fair value, carrying value, redemption value, and related accretion for the three and six months ended June 30, 2023 was deminimus.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 13
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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+ Details