Pyxis Oncology (PYXS) 10-Q 7 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 06, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Document Transition Report	false
Document Quarterly Report	true
Entity Registrant Name	Pyxis Oncology, Inc.
Entity Central Index Key	0001782223
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity File Number	001-40881
Entity Tax Identification Number	83-1160910
Entity Address, Address Line One	321 Harrison Avenue
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02118
Entity Incorporation, State or Country Code	DE
City Area Code	617
Local Phone Number	221-9059
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	PYXS
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		44,323,046

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 14,715	$ 179,293
Marketable debt securities, short-term	118,252
Restricted cash	1,472	1,472
Prepaid expenses and other current assets	4,655	5,847
Total current assets	139,094	186,612
Property and equipment, net	12,175	11,165
Intangible assets, net	22,294
Operating lease right-of-use assets	13,129	13,602
Total assets	186,692	211,379
Current liabilities:
Accounts payable	3,310	7,097
Accrued expenses and other current liabilities	16,629	24,537
Operating lease liabilities, current portion	1,204
Deferred revenue	7,189
Total current liabilities	28,332	31,634
Operating lease liabilities, net of current portion	20,414	18,921
Total liabilities	48,746	50,555
Commitments and contingencies (Note 16)
Stockholders' equity:
Preferred stock, par value $0.001 per share, 10,000,000 shares authorized; zero shares issued and outstanding
Common stock, $0.001 par value per share; 190,000,000 shares; 44,312,767 and 35,110,016 shares issued as of September 30, 2023 and December 31, 2022, respectively, 44,294,092 and 34,958,730 shares outstanding as of June 30, 2023 and December 31, 2022, respectively	44	34
Additional paid-in capital	408,635	373,225
Accumulated other comprehensive loss	(105)
Accumulated deficit	(270,628)	(212,435)
Total stockholders' equity	137,946	160,824
Total liabilities and stockholders' equity	$ 186,692	$ 211,379

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Preferred stock, par or stated value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares issued	44,312,767	35,110,016
Common stock, shares outstanding	44,294,092	34,958,730

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development expense	$ 14,687	$ 19,034	$ 37,979	$ 56,275
General and administrative	10,667	9,359	26,450	29,233
Total operating expenses	25,354	28,393	64,429	85,508
Loss from operations	(25,354)	(28,393)	(64,429)	(85,508)
Other income, net:
Interest and investment income	1,707	719	5,036	892
Sublease income	598		1,200
Total other income, net	2,305	719	6,236	892
Net loss	$ (23,049)	$ (27,674)	$ (58,193)	$ (84,616)
Net loss per common share - basic	$ (0.56)	$ (0.85)	$ (1.52)	$ (2.61)
Net loss per common share - diluted	$ (0.56)	$ (0.85)	$ (1.52)	$ (2.61)
Weighted average shares of common stock outstanding - basic	41,331,806	32,561,228	38,379,401	32,444,072
Weighted average shares of common stock outstanding - diluted	41,331,806	32,561,228	38,379,401	32,444,072
Other comprehensive loss:
Net unrealized loss on marketable debt securities	$ (20)		$ (105)
Other comprehensive loss	(20)		(105)
Comprehensive loss	$ (23,069)	$ (27,674)	$ (58,298)	$ (84,616)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Apexigen, Inc.	Pfizer License Agreement	ESPP	Common Stock	Common Stock Apexigen, Inc.	Common Stock Pfizer License Agreement	Common Stock ESPP	Additional Paid-in Capital	Additional Paid-in Capital Apexigen, Inc.	Additional Paid-in Capital Pfizer License Agreement	Additional Paid-in Capital ESPP	Accumulated Other Comprehensive Income/(Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ 261,313				$ 32				$ 352,999					$ (91,718)
Beginning Balance, Shares at Dec. 31, 2021					32,222,881
Stock options exercised	183								183
Stock options exercised (Shares)					73,841
Vesting of restricted common stock, net of tax withholdings	1								1
Vesting of restricted common stock, net of tax withholdings (Shares)					291,418
Stock-based compensation	11,866								11,866
Net loss	(84,616)													(84,616)
Ending balance at Sep. 30, 2022	188,747				$ 32				365,049					(176,334)
Ending balance (in shares) at Sep. 30, 2022					32,588,140
Beginning balance at Jun. 30, 2022	211,966				$ 32				360,594					(148,660)
Beginning Balance, Shares at Jun. 30, 2022					32,483,883
Stock options exercised	6								6
Stock options exercised (Shares)					9,003
Vesting of restricted common stock, net of tax withholdings (Shares)					95,254
Stock-based compensation	4,449								4,449
Net loss	(27,674)													(27,674)
Ending balance at Sep. 30, 2022	188,747				$ 32				365,049					(176,334)
Ending balance (in shares) at Sep. 30, 2022					32,588,140
Beginning balance at Dec. 31, 2022	160,824				$ 34				373,225					(212,435)
Beginning Balance, Shares at Dec. 31, 2022					34,958,730
Issuance of common stock		$ 10,732	$ 5,000	$ 105		$ 4	$ 2			$ 10,728	$ 4,998	$ 105
Issuance of common stock (Shares)						4,344,435	1,811,594	60,567
Shares issued pursuant to at-the-market ("ATM") program, net of commission	6,122				$ 1				6,121
Shares issued pursuant to at-the-market ("ATM") program, net of commission (Shares)					1,001,208
Stock options exercised	$ 120								120
Stock options exercised (Shares)	77,270				77,270
Vesting of restricted common stock, net of tax withholdings	$ (390)				$ 3				(393)
Vesting of restricted common stock, net of tax withholdings (Shares)					2,040,288
Stock-based compensation	13,731								13,731
Net unrealized gains/(losses) on marketable debt securities	(105)												$ (105)
Net loss	(58,193)													(58,193)
Ending balance at Sep. 30, 2023	137,946				$ 44				408,635				(105)	(270,628)
Ending balance (in shares) at Sep. 30, 2023					44,294,092
Beginning balance at Jun. 30, 2023	145,275				$ 39				392,900				(85)	(247,579)
Beginning Balance, Shares at Jun. 30, 2023					39,376,941
Issuance of common stock		$ 10,732		$ 105		$ 4				$ 10,728		$ 105
Issuance of common stock (Shares)						4,344,435		60,567
Stock options exercised	117								117
Stock options exercised (Shares)					56,774
Vesting of restricted common stock, net of tax withholdings	(393)				$ 1				(394)
Vesting of restricted common stock, net of tax withholdings (Shares)					455,375
Stock-based compensation	5,179								5,179
Net unrealized gains/(losses) on marketable debt securities	(20)												(20)
Net loss	(23,049)													(23,049)
Ending balance at Sep. 30, 2023	$ 137,946				$ 44				$ 408,635				$ (105)	$ (270,628)
Ending balance (in shares) at Sep. 30, 2023					44,294,092

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net loss	$ (58,193)	$ (84,616)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,237	517
Stock-based compensation	13,731	11,866
Non-cash lease expense	473	855
Accretion of discount on marketable debt securities	(3,347)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,712	(332)
Accounts payable	(3,857)	(6,443)
Accrued expenses and other current liabilities	(10,435)	5,636
Operating lease liabilities	2,697	569
Deferred revenue	527
Net cash used in operating activities	(55,455)	(71,948)
Investing activities
Cash acquired in acquisition of Apexigen, Inc.	6,659
Redemption of marketable debt securities	71,594
Purchase of marketable debt securities	(186,604)
Purchase of property and equipment	(6,726)	(4,541)
Net cash used in investing activities	(115,077)	(4,541)
Financing activities
Proceeds from shares issued under ATM, net of commission	6,122
Tax withholding payments related to net settlement of restricted stock units	(393)
Proceeds from the exercise of stock options	120	183
Proceeds from the sale of stock under employee stock purchase plan	105
Net cash provided by financing activities	5,954	183
Net decrease in cash, cash equivalents, and restricted cash	(164,578)	(76,306)
Cash, cash equivalents and restricted cash at beginning of year	180,765	276,316
Cash, cash equivalents and restricted cash at end of period	16,187	200,010
Supplemental cash flow information:
Cash received for interest	1,658	892
Cash paid for taxes	48
Noncash investing activities:
Shares, warrants, and replacement stock options and restricted stock units ("RSUs") issued for acquisition of Apexigen, Inc.	10,732
Property and equipment in accounts payable and accrued expenses		1,360
Operating lease right-of-use assets obtained in exchange for operating lease liabilities		15,319
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	14,715	198,538
Restricted cash	1,472	1,472
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 16,187	$ 200,010

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	1. Description of Business Nature of Business Pyxis Oncology, Inc. (the “Company”), a Delaware corporation, was founded in June 2018 and launched its operations in July 2019. The Company is a clinical stage company focused on defeating difficult-to-treat cancers. The Company is efficiently building next-generation therapeutics that hold the potential for mono and combination therapies. The Company's therapeutic candidates are designed to directly kill tumor cells and to address the underlying pathologies created by cancer that enable its uncontrollable proliferation and immune evasion. The Company's antibody-drug conjugates (“ADCs”) and immuno-oncology (“IO”) programs employ novel and emerging strategies to target a broad range of solid tumors resistant to current standards of care. The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of assessing performance and allocating resources.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	2. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The Company’s fiscal year ends on December 31 and its first three fiscal quarters end on March 31, June 30 and September 30. The accompanying condensed consolidated financial statements are unaudited. The unaudited condensed consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and follow the requirements of the Securities and Exchange Commission (“SEC”) for interim financial reporting. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements as certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. The Company has no unconsolidated subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). In the opinion of management, the unaudited condensed consolidated financial statements include all normal and recurring adjustments that are considered necessary for the fair statement of results for the interim periods. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of those expected for the year ending December 31, 2023 or for any future period. The condensed consolidated balance sheet as of December 31, 2022 included herein was derived from the audited consolidated financial statements as of that date. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the related notes thereto for the year ended December 31, 2022, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 22, 2023. Liquidity As of September 30, 2023, the Company had an accumulated deficit of $ 270.6 million. The Company has incurred losses and negative cash flows from operations since inception, including net losses of $ 58.2 million and $ 84.6 million for the nine months ended September 30, 2023 and 2022, respectively. The Company has not generated any revenues from product sales to date and does not anticipate generating any revenues from product sales unless and until it successfully completes development and obtains regulatory approval for its current or any future product candidates. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future as the Company continues to expand its research and development programs and develop its product candidates. The Company currently expects that its existing cash, cash equivalents and short-term investments of $ 133.0 million as of September 30, 2023 will fund its operating expenses and capital requirements at least twelve months from the date these unaudited consolidated financial statements are issued. Additional funding may be necessary to fund future clinical and preclinical activities. The Company plans to continue to fund its losses from operations and capital funding needs through public or private equity, convertible or debt financing or other sources. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expense, and related disclosures. The Company regularly evaluates estimates and assumptions related to assets, liabilities, stock-based compensation, operating leases, assessment of the useful lives of property and equipment, marketable debt securities, fair value of intangible assets and research and development costs, including clinical trial accruals. The Company bases its estimates and assumptions on historical experience and on various other factors that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates and there may be changes to management’s estimates in future periods. Risks and Uncertainties The Company is subject to risks common to early-stage companies in the biopharmaceutical industry including, but not limited to, uncertainties related to commercialization of products, regulatory approvals, dependence on key suppliers for active ingredients and third-party service providers such as contract research and manufacturing organizations, protection of intellectual property rights and the ability to make milestone, royalty or other payments due under any license, collaboration or supply agreements. Concentration of Credit Risks Financial instruments which potentially subject the Company to significant concentration of credit risk consist of cash and cash equivalents, restricted cash and short-term investments. The Company invests its excess cash primarily in money market funds and highly liquid U.S. Treasury securities. The Company has adopted an investment policy that includes guidelines relative to credit quality, diversification and maturities to preserve principal and liquidity. Significant Accounting Policies Other than the new accounting policies detailed below, there have been no other changes to the Company’s significant accounting policies disclosed in “Note 2 – Summary of Significant Accounting Policies” of the Company’s Annual Report on Form 10-K filed with the SEC on March 22, 2023. Investments Short-term investments consist of U.S. Treasury securities with original maturities greater than three months. The Company may sell investments at any time for use in current operations even if the investments have not yet reached maturity. As a result, the Company classifies its investments as current assets. All investments have been classified as available-for-sale marketable debt securities. Marketable debt securities are recorded at fair value, with unrealized gains and losses, net of tax, included as a component of accumulated other comprehensive income (loss) in stockholders’ equity (deficit) and a component of total comprehensive loss in the condensed consolidated statements of operations and comprehensive loss, until realized. The fair value of these securities is determined based upon quoted market prices or pricing models for similar securities at period end. Premiums paid or discounts received at the time of purchase of marketable securities, are amortized to interest and investment income over the terms of the related securities. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. At each reporting date the Company will evaluate available-for-sale marketable debt securities in an unrealized loss position, using the discounted cash flow model, to determine whether the unrealized loss or any potential credit losses should be recognized in net loss. For available-for-sale marketable debt securities in an unrealized loss position, the Company will assess (i) whether it intends to sell, or (ii) it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If the aforementioned criteria is met, such marketable debt security’s amortized cost basis will be written down to its fair value through earnings along with any existing allowance for credit losses. For available-for-sale marketable debt securities that do not meet this criteria, the Company will evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings, and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented in the accompanying condensed consolidated statements of operations and comprehensive loss. Business Combinations The Company determines whether a transaction or other event is a business combination by determining whether the assets acquired and liabilities assumed constitute a business. Business combinations are accounted for by applying the acquisition method as set out by ASC 805, Business Combinations (“ASC 805”). The acquisition method of accounting requires the acquirer to recognize and measure all identifiable assets acquired, liabilities assumed and any noncontrolling interest in the acquiree at their acquisition-date fair values, with certain exceptions for specific items. Goodwill is measured as the excess of the consideration transferred in the business combination over the net acquisition date amounts of the identifiable assets acquired and the liabilities assumed. Alternatively, if acquisition date amounts of the identifiable assets acquired and the liabilities assumed exceeds the consideration transferred, a gain on bargain purchase is recognized in the condensed consolidated statements of operations and comprehensive loss. The consideration transferred in a business combination is measured as the sum of the fair values of the assets transferred, the liabilities incurred to former owners of the target and the equity interests issued. The results of operations of businesses acquired by the Company are included in the Company’s condensed consolidated statements of operations and comprehensive loss as of the respective acquisition date. Where the acquirer exchanges its share-based payment awards for awards held by grantees of the acquiree, such exchanges are treated as a modification of share-based payment awards and are referred to as replacement awards. The replacement awards are measured as of the acquisition date and the portion of the fair-value-based measure of the replacement award that is attributable to pre-combination vesting is considered part of the consideration transferred. For awards with service-based vesting conditions only, the amount attributable to pre-combination vesting is the fair-value-based measure of the acquiree award multiplied by the ratio of the employee’s pre-combination service period to the greater of the total service period or the original service period of the acquiree award. Acquisition-related costs, including advisory, legal and other professional fees and administrative fees are expensed as incurred except for the costs of issuing equity securities, which are recognized as a reduction to the amounts recognized in the condensed consolidated statements of stockholders' equity for the respective equity issuance. Indefinite-Lived Intangible Asset The Company’s indefinite-lived intangible assets consist of in-process research and development (“IPR&D”), which was acquired in connection with the acquisition of Apexigen, Inc. (“Apexigen”). IPR&D represents the fair value assigned to research and development projects acquired which are in-process, but not yet completed at the time of acquisition. The primary basis for determining the completion of these projects is obtaining regulatory approval to market the underlying products in an applicable geographic region. The Company classifies IPR&D acquired in a business combination as an indefinite-lived intangible asset until the associated research and development efforts are either completed or abandoned. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts. All research and development costs incurred subsequent to the acquisition of IPR&D are expensed as incurred. Indefinite-lived intangible assets are evaluated for impairment on an annual basis or more frequently if an indicator of impairment is present. Warrants The Company accounts for warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in ASC 480, Distinguishing Liabilities from Equity (“ASC 480”) and ASC 815, Derivatives and Hedging (“ASC 815”). The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, meet the definition of a liability pursuant to ASC 480, and whether the warrants meet all of the requirements for equity classification under ASC 815. This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent quarterly period end date while the warrants are outstanding. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of equity at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as liabilities at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss on the statements of operations. Revenue Recognition The Company recognizes revenue based on guidance under ASC 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, revenue is recognized when the customer obtains control of the promised goods or services, at an amount that reflects the consideration the Company expect to receive in exchange for those goods or services. The Company has not commenced sales of its drug candidates and does not have any products approved for marketing as of September 30, 2023. The Company may also earn contingent fees, including milestone payments, based on counterparty performance and royalties on sales, from collaborations and other out-license arrangements. The Company recognizes milestone payments as revenue once the underlying events are probable of being met and there is not a significant risk of reversal. The Company recognizes sales-based royalties as revenue when the underlying sales occur and there are no constrains to recognize the revenue for such sales-based royalties . Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model that requires the use of forward-looking information to calculate credit loss estimates. It also eliminates the concept of other-than-temporary impairment and requires credit losses on available-for-sale debt securities to be recorded through an allowance for credit losses instead of as a reduction in the amortized cost basis of the securities. On January 1, 2023 , the Company adopted ASU 2016-13, which did not have a material effect on the Company's financial position, results of operations, or cash flows. In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”), which amends the accounting related to contract assets and liabilities acquired in business combinations. ASU 2021-08 requires that entities recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASC Topic 606, Revenue from Contracts with Customers . ASU 2021-08 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, and should be applied prospectively to businesses combinations occurring on or after the effective date of the amendment. Early adoption is permitted, including adoption in an interim period. On January 1, 2023 , the Company adopted ASU 2021-08, which did not have a material effect on the Company's financial position, results of operations, or cash flows. Recently Issued Accounting Pronouncements Recent authoritative guidance issued by the FASB (including technical corrections to the ASC), the American Institute of Certified Public Accountants (“AICPA”), and the SEC did not, or are not expected to, have a material impact on the Company’s unaudited condensed consolidated financial statements and related disclosures.

Acquisition of Apexigen

Acquisition of Apexigen	9 Months Ended
	Sep. 30, 2023
Business Combinations [Abstract]
Acquisition of Apexigen	3. Acquisition of Apexigen On May 23, 2023, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”), by and among the Company, Ascent Merger Sub Corp., a Delaware corporation and wholly-owned subsidiary of the Company (“Merger Sub”), and Apexigen, a Delaware corporation and a clinical-stage biopharmaceutical company focused on discovering and developing innovative antibody therapeutics for oncology. On August 23, 2023 (the “Closing Date”), the Company completed the acquisition of Apexigen contemplated by the Merger Agreement, pursuant to which, Merger Sub merged with and into Apexigen, with Apexigen surviving as a wholly owned subsidiary of the Company (the “Merger”). The Company issued 4,344,435 shares of common stock to Apexigen stockholders. The Merger expanded the pipeline with the addition of sotigalimab (now PYX-107), a potentially first- and best-in-class CD40 agonist with demonstrated anti-cancer activity in patients who previously progressed on PD-(L)1 inhibitors, and enhanced the Company’s ADC capabilities with an addition of the commercially and clinically validated APXiMAB platform to generate novel antibodies that can be optimized for targeted payload delivery. Under the Merger Agreement, each share of Apexigen common stock outstanding as of the Closing Date was automatically converted into the right to receive 0.1725 shares of the Company’s common stock (“Exchange Ratio”). Additionally, each outstanding stock option, RSU and warrant issued by Apexigen was assumed and converted into stock options, RSUs and warrants to acquire the Company’s common stock, on substantially similar terms and conditions as were applicable under such Apexigen equity plans (collectively, the "Replacement Awards") and warrant agreements. The number of stock options, RSUs and warrants and their respective exercise prices were adjusted by the Exchange Ratio. The Company accounted for the Merger as a business combination using the acquisition method in accordance with ASC 805. Under the acquisition method of accounting, the Company was identified as the acquirer, with Apexigen as the acquiree, and August 23, 2023 was determined to be the acquisition date. Accordingly, the assets acquired and liabilities assumed are recorded at their estimated fair value on the date of acquisition. Apexigen’s results of operations have been included in the condensed consolidated statements of operations and comprehensive loss since the date of acquisition and were not material to the Company’s results of operations for the three and nine months ended September 30, 2023. The consideration transferred for Apexigen includes the shares issued by the Company to former Apexigen shareholders, the fair value of replacement awards (both stock options and RSUs) of the Company granted to Apexigen grantholders attributable to pre-combination vesting and the fair value of Apexigen warrants converted to the Company’s warrants. The following table summarizes the acquisition date fair value of the consideration transferred for Apexigen (in thousands, except share and per-share information): Fair value of Pyxis Oncology common stock issued to Apexigen stockholders (i) $ 9,970 Fair value of replacement options and RSUs attributable to pre-combination service (ii) 144 Fair value of replacement warrants (iii) 618 Provisional purchase price $ 10,732 (i) The fair value of the Company’s common stock issued as consideration transferred was based on the closing price of Pyxis Oncology common stock as reported on The Nasdaq Global Select Market on the day prior to the Closing Date. (ii) At the Closing Date, the Company replaced 4,128,809 Apexigen stock options and 200,000 Apexigen RSUs with approximately 712,181 Pyxis Oncology stock options (“Replacement Options”) and 34,500 Pyxis Oncology RSUs (“Replacement RSU Awards”). The acquisition date fair value of the Replacement Options was determined by the Black-Scholes option-pricing model and the acquisition date fair value attributable to the pre-combination services of $ 0.1 million is included in the provisional purchase price. (iii) At the Closing Date, the Company replaced approximately 5,815,613 Apexigen warrants with approximately 1,003,191 Pyxis Oncology warrants (“Replacement Warrants”). The acquisition date fair value of the Replacement Warrants is $ 0.6 million, which was determined using the Black-Scholes option-pricing model and is included in the provisional purchase price. The following table summarizes the preliminary acquisition date fair value of the assets acquired and liabilities assumed (in thousands): Assets acquired: Cash and cash equivalents $ 6,660 Prepaid expenses and other current assets 519 Intangible assets 22,294 Total identifiable assets $ 29,473 Liabilities assumed: Accounts payable ( 4,548 ) Accrued liabilities ( 7,531 ) Deferred revenue ( 6,662 ) Total identifiable liabilities $ ( 18,741 ) Net assets acquired $ 10,732 The assets acquired and liabilities assumed were measured based on management’s estimates of the fair value as of the acquisition date. Intangible assets represents Apexigen's research and development asset, which was in-process, but not yet completed, and which the Company has the opportunity to advance. The fair value of the IPR&D was determined using the income approach. Under this method, an intangible asset's fair value is equal to the present value of the incremental after-tax cash flows attributable to the intangible asset. The fair value measurements were primarily based on significant inputs not observable in the market and thus represent a Level 3 measurement. The estimates the Company uses are consistent with the plans and estimates that it uses to manage its business. Significant assumptions utilized in the Company’s income approach model include the discount rate, timing of clinical studies and regulatory approvals, the probability of success of its research and development programs, timing of commercialization of these programs, forecasted sales, selling, general and administrative expenses, capital expenditures, as well as anticipated growth rates. The fair value estimates for the IPR&D and purchase price are considered provisional and subject to adjustment during the measurement period, not to exceed one year after the date of acquisition, as additional information becomes available and as additional analyses are performed. The Company incurred transaction related costs of $ 1.3 million for the nine months ended September 30, 2023, of which $ 1.0 million were recognized during the three months ended September 30, 2023. All transaction related costs were recognized in general and administrative expenses on the condensed consolidated statements of operations and comprehensive loss. No issuance costs were incurred relating to the issuance of shares to Apexigen stockholders. Supplemental Pro Forma Information On a pro forma basis to give effect to the Merger as if it occurred on January 1, 2022, net loss for the three and nine months ended September 30, 2023 and 2022 would have been as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss $ ( 29,313 ) $ ( 36,166 ) $ ( 74,375 ) $ ( 110,254 ) The supplemental pro forma net loss for the three and nine months ended September 30, 2023 were adjusted to exclude the $ 1.0 million and $ 1.3 million, respectively, of acquisition-related costs recognized by the Company, and the $ 3.7 million and $ 5.5 million, respectively, of acquisition-related costs incurred by Apexigen.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The carrying amounts of the Company’s financial instruments, including prepaid expenses and other current assets, accounts payable and accrued expenses approximate fair value due to their relatively short maturities. The Company’s financial instruments consist of Level I assets which consist primarily of highly liquid money market funds and U.S. Treasury securities that are included in marketable debt securities. The following tables set forth the fair value of the Company’s financial instruments subject to fair value measurements on a recurring basis and the level of inputs used in such measurements in accordance with the FASB ASC 820 hierarchy (in thousands): September 30, 2023 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 10,086 $ — $ — $ 10,086 Marketable debt securities U.S. Treasury securities 118,252 — — 118,252 Total $ 128,338 $ — $ — $ 128,338 December 31, 2022 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 177,279 $ — $ — $ 177,279 Restricted cash Money market funds 1,472 — — 1,472 Total $ 178,751 $ — $ — $ 178,751 Money market funds and U.S. Treasury securities are classified as Level 1 within the fair value hierarchy, as they are valued using quoted prices in active markets. There were no transfers of financial instruments among Level 1, Level 2, and Level 3 during the periods presented.

Marketable Debt Securities

Marketable Debt Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Debt Securities	5. Marketable Debt Securities Marketable debt securities, all of which were classified as available-for-sale, consist of the following (in thousands): September 30, 2023 Amortized Unrealized Unrealized Aggregate Marketable debt securities U.S. Treasury securities $ 118,357 $ 8 $ ( 113 ) $ 118,252 Total $ 118,357 $ 8 $ ( 113 ) $ 118,252 As of December 31, 2022, the Company did no t have marketable debt securities. As of September 30, 2023, the remaining contractual terms of the U.S. Treasury securities are less than 12 months. Interest and Investment Income Interest and investment income consists of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Interest income $ 227 $ 719 $ 1,689 $ 892 Accretion of discount, net 1,480 — 3,347 — Total interest and investment income $ 1,707 $ 719 $ 5,036 $ 892

Joint Venture

Joint Venture	9 Months Ended
	Sep. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Joint Venture	6. Joint Venture In March 2021, the Company entered into definitive transaction agreements with Alloy Therapeutics, Inc. (“Alloy”) and Voxall Therapeutics, LLC (“Voxall”), to finance and operate Voxall, a joint venture company formed in collaboration with Alloy to leverage the Company’s technology and Alloy’s ATX-Gx ™ platform and antibody discovery services. Voxall granted to the Company and Alloy, 50 % of the voting membership units of Voxall in exchange for certain initial contributions. The Company accounted for the investment in Voxall under the equity method of accounting. Voxall has incurred losses since inception and the Company's share in the losses of Voxall was $ 0.1 million for both the three and nine months ended September 30, 2023 and $ 0 for both the three and nine months ended September 30, 2022 The Company recognized its share of losses of Voxall only to the extent of the carrying value of its investment in Voxall and the promissory note issued by Voxall, which aggregated to $ 0.2 million and was recognized during the year ended December 31, 2021. The remaining unabsorbed loss will be offset against future income, if any. As the Company has no commitment to fund the losses of the equity method investment, the carrying value of the equity method investment has not been reduced below zero .

Licensing Agreements

Licensing Agreements	9 Months Ended
	Sep. 30, 2023
License Agreements [Abstract]
Licensing Agreements	7. Licensing Agreements The University of Chicago Agreement In April 2020, the Company entered into a license agreement (the “University License Agreement”), as well as a sponsored research agreement, with the University of Chicago (the “University”). Under the terms of the license, the Company has the global right to develop and commercialize products that are covered by a valid claim of a licensed patent, incorporate or use the licensed know-how and materials or are known to assess, modulate or utilize the activity of certain specified biological targets. In partial consideration for the license from the University, the Company issued to the University 48,919 shares of its common stock in 2020. Pursuant to the University License Agreement, the Company is obligated to pay potential development and commercial milestones as well as running royalties on net sales of licensed products at varying rates. The Company assessed the milestone and royalty events under University License Agreement as of September 30, 2023 and 2022, and determined that no such amounts were required. Pfizer Inc. Agreement In December 2020, the Company entered into a license agreement (as amended, the “Pfizer License Agreement”) with Pfizer Inc. (“Pfizer”) for worldwide development and commercialization rights to ADC product candidates directed to certain licensed targets, including PYX-201 and PYX-203, and products containing the ADC product candidates. The Company’s rights are exclusive with respect to certain patents owned or controlled by Pfizer covering the licensed ADCs. Pfizer has also granted the Company a non-exclusive license to use Pfizer’s ADC technology (“FACT”) platform. The initial licensed targets include CD123 and extra domain B (EDB of fibronectin) and the Company has the option to expand the scope of its license to add additional licensed targets that have not been licensed to a third party or are not the subject of a Pfizer ADC development program. The Pfizer License Agreement became effective in March 2021 and the Company paid a combined $ 25.0 million for the license fee, consisting of an upfront cash payment of $ 5.0 million and issued 12,152,145 shares of Series B convertible preferred stock, which was converted into 1,911,015 shares of its common stock upon the initial public offering ("IPO") in October 2021, with a value of $ 20.0 million to Pfizer. On October 6, 2022, the Company entered into an amended and restated license agreement (the “A&R License Agreement”) with Pfizer, which amends and restates the Pfizer License Agreement. Pursuant to the A&R License Agreement, Pfizer granted to the Company exclusive worldwide rights under Pfizer’s FACT Platform technology to develop and commercialize ADC product candidates directed to certain licensed targets, including PYX-201 and PYX-203, and products containing the ADC product candidates. Additional ADC targets may be licensed for a nominal upfront payment and milestones. In accordance with the terms of the A&R License Agreement, the Company issued 2,229,654 shares of its common stock in October 2022, paid $ 8.0 million to Pfizer in January 2023 and issued 1,811,594 shares of its common stock in March 2023. Further, pursuant to the A&R License Agreement, the Company is obligated to pay future contingent payments including development, regulatory and commercial milestones as well as running royalties on net sales of licensed products at varying rates. The Company assessed the milestone and royalty events under A&R License Agreement as of September 30, 2023 and 2022, and determined that no such amounts were required. LegoChem Biosciences, Inc. Agreements In December 2020, the Company entered into a license agreement (the “LegoChem License Agreement”) and an opt-in, investment and additional consideration agreement (the “Opt-In Agreement”) with LegoChem Biosciences, Inc. (“LegoChem”). Pursuant to the LegoChem License Agreement, the Company obtained a worldwide (other than Korea) license for development and commercialization rights for LCB67, an ADC product candidate targeting DLK-1, and products containing the licensed compound. Additionally, the Company may purchase certain initial quantities of licensed products from LegoChem for an estimated cost of $ 7.0 million. No amounts were due and payable related to the manufacturing of the initial quantities of licensed product as of September 30, 2023. Further, the Company is obligated to make future contingent payments including development, regulatory and commercial milestones as well as running royalties on net sales of licensed products at varying rates. The Company assessed the milestone and royalty events under LegoChem License Agreement as of September 30, 2023 and 2022, and determined that no such amounts were required. License Agreement with Biosion USA, Inc. On March 28, 2022, the Company entered into a license agreement (the “Biosion License Agreement”) with Biosion USA, Inc. (“Biosion”), pursuant to which the Company obtained an exclusive, worldwide (other than Greater China (mainland China, Hong Kong, Macau and Taiwan)) license for development, manufacturing and commercialization rights for BSI-060T, a Siglec-15 targeting antibody, an IO product candidate (now referred to as PYX-106), and products containing the licensed compound. Pursuant to the Biosion License Agreement, the Company paid an upfront license fee of $ 10.0 million in March 2022, which was recorded as research and development expenses. Further, the Company is also obligated to pay future contingent payments including development, regulatory and commercial milestones and, if products are launched, the Company will pay Biosion tiered royalties on net sales of licensed products in varying royalty rates ranging from low single digits to low teens. The Company is also obligated to pay Biosion a percentage of certain sublicensing revenue ranging from mid-double to low-double digits based on the stage of development of the licensed product at the time of entering into the applicable sublicense. The Company assessed the milestone and royalty events involving Biosion as of September 30, 2023 and 2022 and determined that no such amounts were required.

Deferred Revenue

Deferred Revenue	9 Months Ended
	Sep. 30, 2023
Deferred Revenue [Abstract]
Deferred Revenue	8. Deferred Revenue On August 23, 2023 , the Company completed the acquisition of Apexigen, which is detailed in Note 3, Acquisition of Apexigen . As a result of the acquisition, the Company assumed all out-licensing agreements of Apexigen. In October 2019, Novartis’ Beovu® product, which is covered by Apexigen’s out-license agreements, was approved for commercial product sale. Under this agreement, Novartis is obligated to pay to Apexigen a very low single-digit royalty on net sales of the Beovu product. However, Novartis has disputed its obligation to pay these royalties on Beovu sales under this agreement. As a result, the Company has determined that any sales-based Beovu product royalty revenue that the Company may earn under this agreement is currently fully constrained. Deferred revenue represents the royalty proceeds received by Apexigen under this agreement, which was taken over by the Company as of the acquisition date. As of September 30, 2023, deferred revenue totaled $ 7.2 million.

Common Stock Warrant

Common Stock Warrant	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Common Stock Warrant	9. Common Stock Warrants As described in Note 3, Acquisition of Apexigen , pursuant to the Merger Agreement , each outstanding warrant issued by Apexigen as of the Closing Date was assumed and converted into a warrant to acquire the Company’s common stock, on substantially similar terms and conditions as were applicable under such Apexigen warrant agreements. At the Closing Date, the Company replaced approximately 5,815,613 Apexigen warrants with approximately 1,003,191 Pyxis Oncology warrants. The acquisition date fair value of the Replacement Warrants was $ 0.6 million, which is included in the provisional purchase price. The fair value of the Replacement Warrants was determined using the Black-Scholes option-pricing model and the following assumptions: August 23, 2023 Expected volatility 95.0 % Risk-free interest rate 4.36 % - 4.50 % Expected dividend yield 0.00 % Expected term (in years) 3.93 - 4.94 As of September 30, 2023, there were 344,259 warrants outstanding with an exercise price of $ 8.12 per share, 17,212 warrants outstanding with an exercise price of $ 10.14 per share and 641,720 warrants with an exercise price of $ 66.67 per share. Each of the warrants with an exercise price of $ 66.67 per share will expire on the fifth anniversary of July 29, 2022, or earlier upon redemption or liquidation. Each of the warrants with an exercise price of $ 8.12 per share will expire on July 30, 2028, or earlier upon redemption or liquidation. The Company may call the warrants outstanding with an exercise price of $ 10.14 per share for redemption: • in whole or in part; • at a price of $ 0.01 per warrant; • upon a minimum of 30 days’ prior written notice of redemption; and • if, and only if, the last reported closing price of the ordinary shares equals or exceeds $ 104.35 per share for any 20 trading days within a 30 -trading day period on the third trading day prior to the date on which the Company sends the notice of redemption to the warrant holders. If the Company calls these warrants for redemption, management will have the option to require all holders that wish to exercise these warrants to do so on a “cashless basis,” as described in the warrant agreement.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders' Equity	10. Stockholders' Equity Shelf Registration Statement and ATM Offering Program On November 1, 2022, the Company filed a registration statement on Form S-3 with the SEC for the issuance of common stock, preferred stock, warrants, debt securities, rights and units up to an aggregate of $ 250.0 million. On November 14, 2022, the registration statement was declared effective by the SEC. The registration statement includes an ATM offering program for the sale of up to $ 125.0 million of shares of the Company's common stock. Any shares offered and sold in the ATM offering will be issued pursuant to the Company’s effective shelf registration statement on Form S-3 and the related prospectus supplement. Under the ATM, the sales agents may sell shares of common stock by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415(a)(4) of the Securities Act of 1933, as amended. The Company will pay the sales agents a commission rate of up to 3 % of the gross sales proceeds of any shares sold and has agreed to provide the sales agents with customary indemnification, contribution and reimbursement rights. The ATM contains customary representations and warranties and conditions to the placements of the shares pursuant thereto. During the nine months ended September 30, 2023 , the Company completed the sale of an aggregate of 1,001,208 shares of common stock under the ATM offering program with an average gross sale price of $ 6.30 per share, resulting in gross proceeds of $ 6.3 million. The Company paid commissions of $ 0.2 million to the placement agent under the ATM offering program. The Company did no t sell any shares under the ATM offering program during the three months ended September 30, 2023. Preferred Stock There were no issued and outstanding shares of preferred stock as of September 30, 2023 and December 31, 2022. Common Stock Voting, dividend and liquidation rights of the holders of the common stock are subject to and qualified by the rights, powers and preferences of the holders of the preferred stock. Voting —Each holder of outstanding shares of common stock shall be entitled to one vote in respect of each share. Reserved Shares — The Company reserved the following shares of common stock for issuance: September 30, 2023 December 31, 2022 Stock options outstanding 6,022,413 5,720,415 Unvested restricted stock awards and units 3,822,944 3,015,387 Stock options available for issuance 1,348,744 1,697,166 Common stock warrants 1,003,191 — Employee stock purchase plan 584,188 534,675 Total 12,781,480 10,967,643

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation 2022 Equity Inducement Plan On July 1, 2022, the Company’s board of directors approved the 2022 Equity Inducement Plan (the “2022 Plan”), which became effective on that date. The 2022 Plan allows the Company to make equity-based incentive awards to its officers and employees without stockholder approval pursuant to Rule 5635(c)(4) of the NASDAQ Listing Rules, or any successor rule relating to inducement awards. Unless earlier terminated by the Board, 2022 Plan will terminate on the ten th anniversary of the effective date. The Company has initially reserved 1,400,000 shares of its common stock for the issuance of awards under the 2022 Plan. As of September 30, 2023 , options to purchase 425,217 shares of common stock and 282,067 RSUs were outstanding under the 2022 Plan and 634,814 shares remained available for future issuance under the 2022 Plan. 2021 Equity and Incentive Plan On September 27, 2021, the Company’s board of directors and stockholders approved the 2021 Equity and Incentive Plan (the “2021 Plan”), which became effective on October 7, 2021, when the Company’s registration statement was declared effective by the SEC. The 2021 Plan allows the Company to make equity-based and cash-based incentive awards to its officers, employees, directors and consultants. The Company has initially reserved 3,852,807 shares of its common stock for the issuance of awards under the 2021 Plan. The number of shares of common stock reserved for issuance under the 2021 Plan will automatically increase annually on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2022, and continuing until (and including) the fiscal year ending December 31, 2031 by the lesser of (i) 5 % of the total number of shares of common stock outstanding on December 31st of the immediately preceding fiscal year and (ii) the number of shares as may be determined by the board of directors. As a result of the evergreen provision of the 2021 Plan, the Company added an additional 1,755,501 shares of common stock to the 2021 Plan as of January 1, 2023. The maximum number of shares of common stock that may be issued pursuant to the exercise of incentive options under the 2021 Plan is 7,705,614 . Unless earlier terminated by the Board, 2021 Plan will terminate on the ten th anniversary of the effective date. As of September 30, 2023 , options to purchase 2,162,316 shares of common stock and 2,713,673 RSUs were outstanding under the 2021 plan and 538,035 shares remained available for future issuance under the 2021 plan. 2019 Equity Incentive Plan In 2019, the Company established the 2019 Equity and Incentive Plan (the “2019 Plan”), under which the Company is allowed to grant options and restricted stock to its employees and non-employees. The maximum number of shares of common stock reserved for issuance under the 2019 Plan is 4,042,408 shares. Options granted under the 2019 Plan include incentive stock options that can be granted only to the Company’s employees and non-statutory stock options that can be granted to the Company’s employees, consultants, advisors and directors. The 2019 Plan also permits the Company to issue restricted stock awards. Unless earlier terminated by the Board, the 2019 Plan will terminate on the tenth anniversary of the effective date. As of September 30, 2023 , options to purchase 2,349,850 shares of common stock and 770,539 RSUs were outstanding under the 2019 Plan and 175,895 shares remained available for future issuance under the 2019 Plan. Apexigen Equity Incentive Plan Upon the Merger, the Company assumed Apexigen's 2022 Equity Incentive Plan (the “2022 EIP”), which allows the Company to grant options and restricted stock to eligible employees and non-employees. The Company initially reserved 443,912 shares of its common stock for the issuance of awards under the 2022 EIP. The number of shares of common stock reserved for issuance under the 2022 EIP will automatically increase on January 1 of each calendar year, starting on January 1, 2023 through January 1, 2032, in an amount equal to the lesser of (i) 0.8625 % of the total number of shares of common stock outstanding on the last day of the calendar month before the date of each automatic increase, (ii) 554,890 shares, or (iii) such number of shares determined by the administrator of the 2022 EIP. The maximum number of shares of common stock that may be issued pursuant to the exercise of incentive options under the 2022 EIP is 597,077 . Unless earlier terminated by the Board, 2022 EIP will terminate on the tenth anniversary of the effective date. As of September 30, 2023, options to purchase 1,085,030 shares of common stock and 37,990 RSUs were outstanding under the 2022 EIP and zero shares remained available for future issuance under the 2022 EIP. The Company also assumed Apexigen's 2020 Equity Incentive Plan, (“2020 EIP”) as a result of the Merger. Outstanding awards granted under the 2020 EIP will remain subject to the terms of the plan, and shares underlying awards granted under such plan that are cancelled or forfeited will be available for issuance under the 2022 EIP, as applicable. 2021 Employee Stock Purchase Plan On September 27, 2021, the Company’s board of directors and stockholders approved the 2021 Employee Stock Purchase Plan (the “2021 ESPP”), which became effective on October 7, 2021, when the Company’s registration statement was declared effective by the SEC. The 2021 ESPP initially reserved and authorized the issuance of up to a total of 424,595 shares of common stock to participating employees. The number of shares of common stock reserved for issuance under the ESPP w ill automatically increase annually on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2022, and continuing until (and including) the fiscal year ending December 31, 2031 by the lesser of (i) 110,080 shares, (ii) 1 % of the total number of shares of common stock outstanding on December 31st of the immediately preceding fiscal year and (iii) the number of shares as may be determined by the board of directors. As a result of the evergreen provision of the 2021 ESPP, the Company added an additional 110,080 shares of common stock to the 2021 ESPP as of January 1, 2023. During the three and nine months ended September 30, 2023, the Company issued 60,567 shares of common stock pursuant to the ESPP. As of September 30, 2023, the authorized number of shares and shares available for issuance under the 2021 ESPP is 584,188 . Repricing of Outstanding and Unexercised Options On March 24, 2023 and in accordance with the terms of the 2019 Plan, the board of directors approved a stock option repricing (the “Repricing”) where the exercise price of each Relevant Option (as defined below) was reduced to $ 2.21 per share, the closing stock price on the date of approval by the board of directors. “Relevant Options” are all outstanding stock options as of March 24, 2023 (vested or unvested) to acquire shares of the Company’s common stock that were issued to current employees of the Company under the 2019 Plan prior to the Company’s IPO. Members of the board of directors did not participate in the Repricing. The board of directors believes that the Repricing is in the best interests of the Company, as the amended stock options will provide added incentives to retain and motivate key contributors of the Company without incurring the stock dilution resulting from significant additional equity grants or significant additional cash expenditures resulting from additional cash compensation. The board of directors also believes that the Repricing better aligns the interests of the key contributors with the goals of the Company. The option repricing resulted in incremental stock-based compensation of $ 1.1 million, of which $ 0.1 million and $ 0.9 million was recorded as expense in the three and nine months ended September 30, 2023, respectively. The remaining expense will be recognized over the requisite service period in which the stock options vest. Apexigen Replacement Options and Replacement RSU Awards As described in Note 3, Acquisition of Apexigen , pursuant to the Merger Agreement , each outstanding stock option issued by Apexigen as of the Closing Date was assumed and converted into an option to acquire the Company’s common stock and each outstanding restricted stock unit awarded by Apexigen as of the Closing Date was assumed and converted into an award of the Company's common stock, on substantially similar terms and conditions as were applicable under such Apexigen equity plans. At the Closing Date, the Company issued approximately 712,181 Replacement Options and 34,500 Replacement RSU Awards to Apexigen grantholders. The acquisition date fair value of the Replacement Options was determined by the Black-Scholes option-pricing model and the acquisition date fair value attributable to the pre-combination services of $ 0.1 million is included in the provisional purchase price, which is included in Note 3, Acquisition of Apexigen . The Replacement Options and Replacement RSU Awards will continue to vest over the remaining vesting period through the earlier of exercise, expiration or forfeiture. The number of stock options, RSUs and warrants and their respective exercise prices were adjusted by the Exchange Ratio. Stock Options Stock options granted under the 2022 Plan, 2022 EIP, 2020 EIP, 2021 Plan and 2019 Plan (together, the “Plans”) to employees generally vest over four years and expire after 10 years . The summary of stock option activity for the nine months ended September 30, 2023 (in thousands, except share and per share amounts): Number of Options Weighted Average Weighted Average Aggregate Outstanding at January 1, 2023 5,720,415 $ 9.68 8.8 $ 72 Granted 474,725 1.97 Replacement Options (1) 712,181 17.57 Exercised ( 77,270 ) 1.60 Expired ( 305,477 ) 11.8 Forfeited ( 502,161 ) 9.16 Outstanding at September 30, 2023 6,022,413 $ 8.33 (2) 6.4 $ 67 (2) Options exercisable at September 30, 2023 3,429,701 $ 8.82 (2) 6.3 $ 52 (2) (1) Represents Replacement Options issued to Apexigen grantholders pursuant to the Merger Agreement. (2) The weighted average exercise price and aggregate intrinsic value as of September 30, 2023 reflect the impact of the stock option repricing discussed above. The weighted-average grant date fair value of options granted during the three and nine months ended September 30, 2023 was $ 1.29 and $ 1.58 per share, respectively, and $ 1.90 and $ 3.35 per share, respectively, for the three and nine months ended September 30, 2022. The aggregate intrinsic value is calculated as the difference between the exercise price of all outstanding and exercisable stock options and the fair value of the Company’s common stock of $ 1.99 per share as of September 29, 2023. The aggregate intrinsic value of stock options exercised during each of the three and nine months ended September 30, 2023 was $ 0.1 million. For the three and nine months ended September 30, 2022, the aggregate intrinsic value of stock options exercised was $ 18 thousand and $ 0.2 million, respectively. The Company estimated the fair value of each option, including Replacement Options, on the date of grant using the Black-Scholes option-pricing model applying the range of assumptions in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Expected volatility 98.23 % - 118.90 % 96.09 % - 97.34 % 97.11 % - 118.90 % 96.09 % - 101.66 % Risk-free interest rate 4.36 % - 5.57 % 2.85 % - 4.02 % 3.58 % - 5.57 % 1.6 % - 4.02 % Expected dividend yield 0.00 % 0.00 % 0.00 % 0.00 % Expected term (in years) 0.25 - 6.08 6.00 - 6.08 0.25 - 6.08 6.00 - 6.11 Stock-based compensation expense related to stock options, including expense related to the Company's ESPP, is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 775 $ 1,623 $ 3,122 $ 3,190 General and administrative 1,668 1,534 5,491 6,134 Total $ 2,443 $ 3,157 $ 8,613 $ 9,324 The Company has an aggregate $ 14.5 million of unrecognized stock-based compensation expense as of September 30, 2023 , remaining to be amortized over a weighted average period of 1.41 years. The Company has not recognized and does not expect to recognize in the near future, any tax benefit related to employee stock-based compensation expense as a result of the full valuation allowance related to its net deferred tax assets. Restricted Stock Awards Under the 2019 Plan, 2021 Plan and 2022 Inducement Plan, the Company issued 3,653,248 RSUs to employees and non-employees. Compensation costs related to these RSUs were recorded based on the Company's stock price on the date of issuance and amortized over the service period. Under the 2019 Plan, 2021 Plan and 2022 Inducement Plan, the Company has 70 days to settle the RSUs once vested. Additionally, the Company issued certain shares of restricted common stock (“RSA” ) to the employee co-founders and certain non-employee consultants in 2019. The shares of restricted common stock were issued pursuant to standalone restricted stock purchase agreements that are independent of the 2019 Plan, 2021 Plan and 2022 Inducement Plan. The shares of restricted common stock pursuant to standalone restricted stock purchase agreements carried a purchase price equivalent of $ 0.01 per share. As of September 30, 2023 , 18,675 RSAs were unvested and outstanding . Under the terms of the restricted stock purchase agreements, the Company has a repurchase option whereby it has the right to repurchase any unvested shares upon termination at a price per share equal to the lesser of (i) the fair market value of the Company’s common stock on the date of repurchase and (ii) the original purchase price. The shares of restricted common stock issued to the Company’s co-founders and non-employee consultants vest based on a predefined number of shares. The Company recognized an associated deposit liability for restricted stock awards issued pursuant to standalone restricted stock purchase agreements upon issuance based on the purchase price of the awards as the unvested shares are subject to repurchase upon termination. As the awards of restricted stock vest, the Company reclassifies the deposit liability to additional paid-in capital. The compensation cost was measured based on the fair value of the underlying common stock less the purchase price of the restricted common stock and the Company recognizes compensation costs over the requisite service period. The summary of restricted stock activity for the nine months ended September 30, 2023: Number of Shares Weighted Average Non-vested and unsettled at January 1, 2023 3,015,387 $ 3.64 Granted 3,653,248 2.18 Replacement RSU Awards (1) 34,500 2.30 Forfeited ( 654,960 ) 3.38 Vested and settled ( 2,225,231 ) 2.84 Non-vested and unsettled at September 30, 2023 3,822,944 $ 2.63 (1) Represents Replacement RSU Awards issued to eligible Apexigen grantholders pursuant to the Merger Agreement. The Company has recorded stock-based compensation expense related to the restricted stock awards of $ 2.7 million and $ 1.3 million for the three months ended September 30, 2023 and 2022, respectively, and $ 5.1 million and $ 2.5 million for the nine months ended September 30, 2023 and 2022, respectively. The Company has an aggregate $ 8.0 million of gross unrecognized restricted stock-based compensation expense as of September 30, 2023 remaining to be amortized over a weighted average period of 2.35 years.

Operating Leases

Operating Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Operating Leases	12. Operating Leases Leases classified as operating leases are included in operating lease right-of-use assets (“ROU”), operating lease liabilities, current portion and operating lease liabilities, net of current portion, in the Company's condensed consolidated balance sheets. Cash paid for operating lease liabilities was $ 1.7 million and $ 1.3 million during the nine months ended September 30, 2023 and 2022, respectively, which is included in operating cash flows. On February 2, 2023, the Company entered into a sublease agreement for approximately 17,729 square feet of office and laboratory space in the building located at 321 Harrison Avenue, Boston, Massachusetts. The sublease included a rent-free period, with rent payments commencing on May 24, 2023. Under the terms of the sublease, the sublessee is to pay the Company approximately $ 1.5 million in year one and $ 1.9 million per year thereafter, which is subject to a 3.0 % annual rent increase, plus certain other costs under the sublease, such as operating expenses, taxes, insurance, property management fee and utilities. The Company remains jointly and severally liable under the head lease and accounts for the sublease as an operating lease. The lease term commenced on March 24, 2023 and is expected to end in March 2026. The sublessee has the option to extend the sublease for a one-year period on the same terms and conditions as the current sublease, subject to a change in base rent for the extended period equal to a 3 % increase to the then current rent. Upon execution of the sublease agreement, the sublessee provided the Company a security deposit of $ 0.4 million which is held in the form of a letter of credit. The Company recognized sublease income of $ 0.6 million and $ 1.2 million for the three and nine months ended September 30, 2023, respectively. The components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Lease cost Operating lease cost $ 678 $ 660 $ 1,997 $ 1,392 Variable lease cost 230 12 518 116 Short-term lease cost — 482 488 1,058 Total lease cost $ 908 $ 1,154 $ 3,003 $ 2,566 Variable lease costs primarily relate to common area costs and other operating costs, which are assessed based on the Company’s proportionate share of such costs for the leased premises. The weighted-average remaining lease term and weighted-average discount rate for operating leases were: As of September 30, 2023 Weighted-average remaining lease term (in years) 9.10 Weighted-average discount rate 9.40 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes The Company’s effective tax rate from continuing operations was 0 % for the three and nine months ended September 30, 2023 and 2022. The Company has no t recorded a federal income tax provision for the three and nine months ended September 30, 2023 and 2022. The Company recorded a nominal state and local income tax provision for the three and nine months ended September 30, 2023 and 2022. The Company assesses the realizability of the deferred tax assets at each reporting date. The Company continues to maintain a full valuation allowance for its U.S. federal and state deferred tax assets, which significantly consists of net operating losses and tax credits. If certain substantial changes in the entity's ownership occur, there may be an annual limitation on the amount of the carryforwards that can be utilized. The Company will continue to assess the need for a valuation allowance on its deferred tax assets.

Net Loss per Common Share

Net Loss per Common Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss per Common Share	14. Net Loss per Common Share Basic and diluted net loss per common share was calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ ( 23,049 ) $ ( 27,674 ) $ ( 58,193 ) $ ( 84,616 ) Denominator: Weighted-average common shares outstanding, basic and diluted 41,331,806 32,561,228 38,379,401 32,444,072 Net loss per share, basic and diluted $ ( 0.56 ) $ ( 0.85 ) $ ( 1.52 ) $ ( 2.61 ) The Company’s potentially dilutive securities, which include restricted stock, and stock options, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The following potentially dilutive securities have been excluded from the calculation of diluted net loss per common share due to their anti-dilutive effect: September 30, 2023 2022 Stock options outstanding 6,022,413 5,835,740 Unvested restricted stock awards and units 3,822,944 3,124,325 Stock options available for issuance 1,348,744 1,581,813 Common stock warrants 1,003,191 — Employee stock purchase plan 584,188 534,675 Total 12,781,480 11,076,553

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Parties	15. Related Parties The Company was founded out of Dr. Thomas Gajewski’s laboratory at the University of Chicago. In 2020, the Company entered into the License Agreement with the University of Chicago, as well as a sponsored research agreement. During the three and nine months ended September 30, 2023 and 2022, the Company did no t incur expenses related to the University License Agreement. Refer to Note 7 for additional discussion. Pfizer owns more than 10 % of the Company and is considered the principal owner of the Company. During the three and nine months ended September 30, 2023 and 2022, the Company did no t incur expenses related to Pfizer. Refer to Note 7 for additional discussion. The Company and Alloy formed a joint venture company, Voxall Therapeutics, LLC (“Voxall”) to leverage the Company’s technology and Alloy’s ATX-Gx™ platform and antibody discovery services. During the three and nine months ended September 30, 2023 and 2022, the Company did no t incur expenses related to Voxall. Refer to Note 6 for additional discussion.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. Commitments and Contingencies Legal Proceedings From time to time, the Company may become involved in various legal proceedings that arise in the ordinary course of business. The Company is not currently a party to any material legal proceedings and is not aware of any pending or threatened legal proceeding against it that the Company believes could have an adverse effect on its business, operating results or financial condition. Commitments In the normal course of business, the Company enters into agreements with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes, which are generally cancellable by the Company at any time, subject to payment of remaining obligations under binding purchase orders and, in certain cases, nominal early-termination fees. These commitments are not deemed significant.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Event	17. Subsequent Event Corporate Restructuring On November 7, 2023, the Company announced a corporate reorganization of its operations to refocus its efforts on progressing the clinical trials of PYX-201 and PYX-106. As part of the reorganization, the Company is undertaking cost-saving initiatives, including a workforce reduction of approximately 40 % of its current employees and pausing funding of certain early-stage research programs. The total cost is estimated to be approximately $ 1.4 million, which relates primarily to severance payments. The Company expects to recognize these costs in the fourth quarter of 2023. These estimates are preliminary and subject to change. As a result of the corporate reorganization, the Company expects its existing cash, cash equivalents and investments will be sufficient to fund its operating and capital needs into early 2026. The Company is also seeking additional non-dilutive funding through the potential monetization of its acquired Apexigen royalty streams. Additionally, the Company is evaluating partnerships of several assets that the Company has chosen not to move into the clinic and potential antibody and ADC platform technology collaborations.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Nature of Business	Nature of Business Pyxis Oncology, Inc. (the “Company”), a Delaware corporation, was founded in June 2018 and launched its operations in July 2019. The Company is a clinical stage company focused on defeating difficult-to-treat cancers. The Company is efficiently building next-generation therapeutics that hold the potential for mono and combination therapies. The Company's therapeutic candidates are designed to directly kill tumor cells and to address the underlying pathologies created by cancer that enable its uncontrollable proliferation and immune evasion. The Company's antibody-drug conjugates (“ADCs”) and immuno-oncology (“IO”) programs employ novel and emerging strategies to target a broad range of solid tumors resistant to current standards of care. The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of assessing performance and allocating resources.
Basis of Presentation	Basis of Presentation The Company’s fiscal year ends on December 31 and its first three fiscal quarters end on March 31, June 30 and September 30. The accompanying condensed consolidated financial statements are unaudited. The unaudited condensed consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and follow the requirements of the Securities and Exchange Commission (“SEC”) for interim financial reporting. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements as certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. The Company has no unconsolidated subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). In the opinion of management, the unaudited condensed consolidated financial statements include all normal and recurring adjustments that are considered necessary for the fair statement of results for the interim periods. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of those expected for the year ending December 31, 2023 or for any future period. The condensed consolidated balance sheet as of December 31, 2022 included herein was derived from the audited consolidated financial statements as of that date. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the related notes thereto for the year ended December 31, 2022, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 22, 2023.
Liquidity	Liquidity As of September 30, 2023, the Company had an accumulated deficit of $ 270.6 million. The Company has incurred losses and negative cash flows from operations since inception, including net losses of $ 58.2 million and $ 84.6 million for the nine months ended September 30, 2023 and 2022, respectively. The Company has not generated any revenues from product sales to date and does not anticipate generating any revenues from product sales unless and until it successfully completes development and obtains regulatory approval for its current or any future product candidates. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future as the Company continues to expand its research and development programs and develop its product candidates. The Company currently expects that its existing cash, cash equivalents and short-term investments of $ 133.0 million as of September 30, 2023 will fund its operating expenses and capital requirements at least twelve months from the date these unaudited consolidated financial statements are issued. Additional funding may be necessary to fund future clinical and preclinical activities. The Company plans to continue to fund its losses from operations and capital funding needs through public or private equity, convertible or debt financing or other sources. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects.
Use of Estimates	Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expense, and related disclosures. The Company regularly evaluates estimates and assumptions related to assets, liabilities, stock-based compensation, operating leases, assessment of the useful lives of property and equipment, marketable debt securities, fair value of intangible assets and research and development costs, including clinical trial accruals. The Company bases its estimates and assumptions on historical experience and on various other factors that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates and there may be changes to management’s estimates in future periods.
Risks and Uncertainties	Risks and Uncertainties The Company is subject to risks common to early-stage companies in the biopharmaceutical industry including, but not limited to, uncertainties related to commercialization of products, regulatory approvals, dependence on key suppliers for active ingredients and third-party service providers such as contract research and manufacturing organizations, protection of intellectual property rights and the ability to make milestone, royalty or other payments due under any license, collaboration or supply agreements.
Concentration of Credit Risk	Concentration of Credit Risks Financial instruments which potentially subject the Company to significant concentration of credit risk consist of cash and cash equivalents, restricted cash and short-term investments. The Company invests its excess cash primarily in money market funds and highly liquid U.S. Treasury securities. The Company has adopted an investment policy that includes guidelines relative to credit quality, diversification and maturities to preserve principal and liquidity.
Significant Accounting Policies	Significant Accounting Policies Other than the new accounting policies detailed below, there have been no other changes to the Company’s significant accounting policies disclosed in “Note 2 – Summary of Significant Accounting Policies” of the Company’s Annual Report on Form 10-K filed with the SEC on March 22, 2023.
Investments	Investments Short-term investments consist of U.S. Treasury securities with original maturities greater than three months. The Company may sell investments at any time for use in current operations even if the investments have not yet reached maturity. As a result, the Company classifies its investments as current assets. All investments have been classified as available-for-sale marketable debt securities. Marketable debt securities are recorded at fair value, with unrealized gains and losses, net of tax, included as a component of accumulated other comprehensive income (loss) in stockholders’ equity (deficit) and a component of total comprehensive loss in the condensed consolidated statements of operations and comprehensive loss, until realized. The fair value of these securities is determined based upon quoted market prices or pricing models for similar securities at period end. Premiums paid or discounts received at the time of purchase of marketable securities, are amortized to interest and investment income over the terms of the related securities. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. At each reporting date the Company will evaluate available-for-sale marketable debt securities in an unrealized loss position, using the discounted cash flow model, to determine whether the unrealized loss or any potential credit losses should be recognized in net loss. For available-for-sale marketable debt securities in an unrealized loss position, the Company will assess (i) whether it intends to sell, or (ii) it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If the aforementioned criteria is met, such marketable debt security’s amortized cost basis will be written down to its fair value through earnings along with any existing allowance for credit losses. For available-for-sale marketable debt securities that do not meet this criteria, the Company will evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings, and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented in the accompanying condensed consolidated statements of operations and comprehensive loss.
Business Combinations	Business Combinations The Company determines whether a transaction or other event is a business combination by determining whether the assets acquired and liabilities assumed constitute a business. Business combinations are accounted for by applying the acquisition method as set out by ASC 805, Business Combinations (“ASC 805”). The acquisition method of accounting requires the acquirer to recognize and measure all identifiable assets acquired, liabilities assumed and any noncontrolling interest in the acquiree at their acquisition-date fair values, with certain exceptions for specific items. Goodwill is measured as the excess of the consideration transferred in the business combination over the net acquisition date amounts of the identifiable assets acquired and the liabilities assumed. Alternatively, if acquisition date amounts of the identifiable assets acquired and the liabilities assumed exceeds the consideration transferred, a gain on bargain purchase is recognized in the condensed consolidated statements of operations and comprehensive loss. The consideration transferred in a business combination is measured as the sum of the fair values of the assets transferred, the liabilities incurred to former owners of the target and the equity interests issued. The results of operations of businesses acquired by the Company are included in the Company’s condensed consolidated statements of operations and comprehensive loss as of the respective acquisition date. Where the acquirer exchanges its share-based payment awards for awards held by grantees of the acquiree, such exchanges are treated as a modification of share-based payment awards and are referred to as replacement awards. The replacement awards are measured as of the acquisition date and the portion of the fair-value-based measure of the replacement award that is attributable to pre-combination vesting is considered part of the consideration transferred. For awards with service-based vesting conditions only, the amount attributable to pre-combination vesting is the fair-value-based measure of the acquiree award multiplied by the ratio of the employee’s pre-combination service period to the greater of the total service period or the original service period of the acquiree award. Acquisition-related costs, including advisory, legal and other professional fees and administrative fees are expensed as incurred except for the costs of issuing equity securities, which are recognized as a reduction to the amounts recognized in the condensed consolidated statements of stockholders' equity for the respective equity issuance.
Indefinite-Lived Intangible Asset	Indefinite-Lived Intangible Asset The Company’s indefinite-lived intangible assets consist of in-process research and development (“IPR&D”), which was acquired in connection with the acquisition of Apexigen, Inc. (“Apexigen”). IPR&D represents the fair value assigned to research and development projects acquired which are in-process, but not yet completed at the time of acquisition. The primary basis for determining the completion of these projects is obtaining regulatory approval to market the underlying products in an applicable geographic region. The Company classifies IPR&D acquired in a business combination as an indefinite-lived intangible asset until the associated research and development efforts are either completed or abandoned. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts. All research and development costs incurred subsequent to the acquisition of IPR&D are expensed as incurred. Indefinite-lived intangible assets are evaluated for impairment on an annual basis or more frequently if an indicator of impairment is present.
Warrants	Warrants The Company accounts for warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in ASC 480, Distinguishing Liabilities from Equity (“ASC 480”) and ASC 815, Derivatives and Hedging (“ASC 815”). The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, meet the definition of a liability pursuant to ASC 480, and whether the warrants meet all of the requirements for equity classification under ASC 815. This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent quarterly period end date while the warrants are outstanding. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of equity at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as liabilities at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss on the statements of operations.
Revenue Recognition	Revenue Recognition The Company recognizes revenue based on guidance under ASC 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, revenue is recognized when the customer obtains control of the promised goods or services, at an amount that reflects the consideration the Company expect to receive in exchange for those goods or services. The Company has not commenced sales of its drug candidates and does not have any products approved for marketing as of September 30, 2023. The Company may also earn contingent fees, including milestone payments, based on counterparty performance and royalties on sales, from collaborations and other out-license arrangements. The Company recognizes milestone payments as revenue once the underlying events are probable of being met and there is not a significant risk of reversal. The Company recognizes sales-based royalties as revenue when the underlying sales occur and there are no constrains to recognize the revenue for such sales-based royalties .
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model that requires the use of forward-looking information to calculate credit loss estimates. It also eliminates the concept of other-than-temporary impairment and requires credit losses on available-for-sale debt securities to be recorded through an allowance for credit losses instead of as a reduction in the amortized cost basis of the securities. On January 1, 2023 , the Company adopted ASU 2016-13, which did not have a material effect on the Company's financial position, results of operations, or cash flows. In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”), which amends the accounting related to contract assets and liabilities acquired in business combinations. ASU 2021-08 requires that entities recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASC Topic 606, Revenue from Contracts with Customers . ASU 2021-08 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, and should be applied prospectively to businesses combinations occurring on or after the effective date of the amendment. Early adoption is permitted, including adoption in an interim period. On January 1, 2023 , the Company adopted ASU 2021-08, which did not have a material effect on the Company's financial position, results of operations, or cash flows. Recently Issued Accounting Pronouncements Recent authoritative guidance issued by the FASB (including technical corrections to the ASC), the American Institute of Certified Public Accountants (“AICPA”), and the SEC did not, or are not expected to, have a material impact on the Company’s unaudited condensed consolidated financial statements and related disclosures.

Acquisition of Apexigen (Tables

Acquisition of Apexigen (Tables)	9 Months Ended
	Sep. 30, 2023
Business Combinations [Abstract]
Summary of Acquisition Date Fair Value of Consideration Transferred	The following table summarizes the acquisition date fair value of the consideration transferred for Apexigen (in thousands, except share and per-share information): Fair value of Pyxis Oncology common stock issued to Apexigen stockholders (i) $ 9,970 Fair value of replacement options and RSUs attributable to pre-combination service (ii) 144 Fair value of replacement warrants (iii) 618 Provisional purchase price $ 10,732
Summary of Preliminary Acquisition Date Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary acquisition date fair value of the assets acquired and liabilities assumed (in thousands): Assets acquired: Cash and cash equivalents $ 6,660 Prepaid expenses and other current assets 519 Intangible assets 22,294 Total identifiable assets $ 29,473 Liabilities assumed: Accounts payable ( 4,548 ) Accrued liabilities ( 7,531 ) Deferred revenue ( 6,662 ) Total identifiable liabilities $ ( 18,741 ) Net assets acquired $ 10,732
Schedule of Supplemental Pro Forma Information	On a pro forma basis to give effect to the Merger as if it occurred on January 1, 2022, net loss for the three and nine months ended September 30, 2023 and 2022 would have been as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss $ ( 29,313 ) $ ( 36,166 ) $ ( 74,375 ) $ ( 110,254 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Carried at Fair Value on Recurring Basis	The following tables set forth the fair value of the Company’s financial instruments subject to fair value measurements on a recurring basis and the level of inputs used in such measurements in accordance with the FASB ASC 820 hierarchy (in thousands): September 30, 2023 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 10,086 $ — $ — $ 10,086 Marketable debt securities U.S. Treasury securities 118,252 — — 118,252 Total $ 128,338 $ — $ — $ 128,338 December 31, 2022 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 177,279 $ — $ — $ 177,279 Restricted cash Money market funds 1,472 — — 1,472 Total $ 178,751 $ — $ — $ 178,751

Marketable Debt Securities (Tab

Marketable Debt Securities (Table)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities Classified as Available-for-sale	Marketable debt securities, all of which were classified as available-for-sale, consist of the following (in thousands): September 30, 2023 Amortized Unrealized Unrealized Aggregate Marketable debt securities U.S. Treasury securities $ 118,357 $ 8 $ ( 113 ) $ 118,252 Total $ 118,357 $ 8 $ ( 113 ) $ 118,252
Interest and Investment Income	Interest and investment income consists of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Interest income $ 227 $ 719 $ 1,689 $ 892 Accretion of discount, net 1,480 — 3,347 — Total interest and investment income $ 1,707 $ 719 $ 5,036 $ 892

Common Stock Warrant (Tables)

Common Stock Warrant (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Fair Value of Replacement Warrants Black-Scholes Option Pricing Model	The fair value of the Replacement Warrants was determined using the Black-Scholes option-pricing model and the following assumptions: August 23, 2023 Expected volatility 95.0 % Risk-free interest rate 4.36 % - 4.50 % Expected dividend yield 0.00 % Expected term (in years) 3.93 - 4.94

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Common Stock Reserved for Issuance	Reserved Shares — The Company reserved the following shares of common stock for issuance: September 30, 2023 December 31, 2022 Stock options outstanding 6,022,413 5,720,415 Unvested restricted stock awards and units 3,822,944 3,015,387 Stock options available for issuance 1,348,744 1,697,166 Common stock warrants 1,003,191 — Employee stock purchase plan 584,188 534,675 Total 12,781,480 10,967,643

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The summary of stock option activity for the nine months ended September 30, 2023 (in thousands, except share and per share amounts): Number of Options Weighted Average Weighted Average Aggregate Outstanding at January 1, 2023 5,720,415 $ 9.68 8.8 $ 72 Granted 474,725 1.97 Replacement Options (1) 712,181 17.57 Exercised ( 77,270 ) 1.60 Expired ( 305,477 ) 11.8 Forfeited ( 502,161 ) 9.16 Outstanding at September 30, 2023 6,022,413 $ 8.33 (2) 6.4 $ 67 (2) Options exercisable at September 30, 2023 3,429,701 $ 8.82 (2) 6.3 $ 52 (2) (1) Represents Replacement Options issued to Apexigen grantholders pursuant to the Merger Agreement. (2) The weighted average exercise price and aggregate intrinsic value as of September 30, 2023 reflect the impact of the stock option repricing discussed above.
Schedule of Estimated Fair Value Assumptions	The Company estimated the fair value of each option, including Replacement Options, on the date of grant using the Black-Scholes option-pricing model applying the range of assumptions in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Expected volatility 98.23 % - 118.90 % 96.09 % - 97.34 % 97.11 % - 118.90 % 96.09 % - 101.66 % Risk-free interest rate 4.36 % - 5.57 % 2.85 % - 4.02 % 3.58 % - 5.57 % 1.6 % - 4.02 % Expected dividend yield 0.00 % 0.00 % 0.00 % 0.00 % Expected term (in years) 0.25 - 6.08 6.00 - 6.08 0.25 - 6.08 6.00 - 6.11
Summary of Stock-Based Compensation Expense	Stock-based compensation expense related to stock options, including expense related to the Company's ESPP, is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 775 $ 1,623 $ 3,122 $ 3,190 General and administrative 1,668 1,534 5,491 6,134 Total $ 2,443 $ 3,157 $ 8,613 $ 9,324
Summary of Restricted Stock Activity	The summary of restricted stock activity for the nine months ended September 30, 2023: Number of Shares Weighted Average Non-vested and unsettled at January 1, 2023 3,015,387 $ 3.64 Granted 3,653,248 2.18 Replacement RSU Awards (1) 34,500 2.30 Forfeited ( 654,960 ) 3.38 Vested and settled ( 2,225,231 ) 2.84 Non-vested and unsettled at September 30, 2023 3,822,944 $ 2.63 (1) Represents Replacement RSU Awards issued to eligible Apexigen grantholders pursuant to the Merger Agreement.

Operating Leases (Tables)

Operating Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Lease cost Operating lease cost $ 678 $ 660 $ 1,997 $ 1,392 Variable lease cost 230 12 518 116 Short-term lease cost — 482 488 1,058 Total lease cost $ 908 $ 1,154 $ 3,003 $ 2,566
Weighted Average Remaining Lease Term and Discount Rate	The weighted-average remaining lease term and weighted-average discount rate for operating leases were: As of September 30, 2023 Weighted-average remaining lease term (in years) 9.10 Weighted-average discount rate 9.40 %

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Common Share	Basic and diluted net loss per common share was calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ ( 23,049 ) $ ( 27,674 ) $ ( 58,193 ) $ ( 84,616 ) Denominator: Weighted-average common shares outstanding, basic and diluted 41,331,806 32,561,228 38,379,401 32,444,072 Net loss per share, basic and diluted $ ( 0.56 ) $ ( 0.85 ) $ ( 1.52 ) $ ( 2.61 )
Anti-Dilutive Effect Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following potentially dilutive securities have been excluded from the calculation of diluted net loss per common share due to their anti-dilutive effect: September 30, 2023 2022 Stock options outstanding 6,022,413 5,835,740 Unvested restricted stock awards and units 3,822,944 3,124,325 Stock options available for issuance 1,348,744 1,581,813 Common stock warrants 1,003,191 — Employee stock purchase plan 584,188 534,675 Total 12,781,480 11,076,553

Description of Business - Addit

Description of Business - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023 Segment
Segment Reporting [Abstract]
Operating and Reporting Segment	1

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit	$ (270,628)		$ (270,628)		$ (212,435)
Net loss	23,049	$ 27,674	58,193	$ 84,616
Cash, cash equivalents and short-term investments	$ 133,000		$ 133,000
ASU 2016-13
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2023		Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect [true false]	true		true
ASU 2021-08
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2023		Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect [true false]	true		true

Acquisition of Apexigen - Addit

Acquisition of Apexigen - Additional Information (Details) - USD ($)		3 Months Ended	9 Months Ended
	Aug. 23, 2023	Sep. 30, 2023	Sep. 30, 2023
Business Acquisition [Line Items]
Right to receive shares conversion	0.1725
Acquisition-related costs		$ 1,000,000	$ 1,300,000
General and Administrative
Business Acquisition [Line Items]
Transaction related costs, incurred		1,300,000	1,300,000
Transaction related costs recognized		1,000,000	1,300,000
Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	34,500
Apexigen, Inc.
Business Acquisition [Line Items]
Stock issued	4,344,435
Issuance costs, incurred			0
Acquisition-related costs		$ 3,700,000	$ 5,500,000
Apexigen, Inc. | Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	200,000
Pyxis Oncology | Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	34,500

Acquisition of Apexigen - Summa

Acquisition of Apexigen - Summary of Acquisition Date Fair Value of Consideration Transferred (Details) - Apexigen, Inc. - USD ($) $ in Thousands		9 Months Ended
	Aug. 23, 2023	Sep. 30, 2023
Business Acquisition [Line Items]
Fair value of consideration transferred	$ 9,970
Provisional purchase price	10,732
Replacement Options and RSU
Business Acquisition [Line Items]
Fair value of consideration transferred	144
Replacement Warrants
Business Acquisition [Line Items]
Fair value of consideration transferred	$ 618	$ 600

Acquisition of Apexigen - Sum_2

Acquisition of Apexigen - Summary of Preliminary Acquisition Date Fair Value of Assets Acquired and Liabilities Assumed (Details) $ in Thousands	Aug. 23, 2023 USD ($)
Assets acquired:
Cash and cash equivalents	$ 6,660
Prepaid expenses and other current assets	519
Intangible assets	22,294
Total identifiable assets	29,473
Liabilities assumed:
Accounts payable	(4,548)
Accrued liabilities	(7,531)
Deferred revenue	(6,662)
Total identifiable liabilities	(18,741)
Net assets acquired	$ 10,732

Acquisition of Apexigen - Sum_3

Acquisition of Apexigen - Summary of Preliminary Acquisition Date Fair Value of Assets Acquired and Liabilities Assumed (Parenthetical) (Details) - USD ($) $ in Thousands		9 Months Ended
	Aug. 23, 2023	Sep. 30, 2023
Replacement Options
Business Acquisition [Line Items]
Number of Options, Replacement Options	712,181
Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	34,500
Apexigen, Inc.
Business Acquisition [Line Items]
Acquisition date fair value of replacement awards	$ 9,970
Apexigen, Inc. | Replacement Options
Business Acquisition [Line Items]
Number of Options, Replacement Options	4,128,809
Apexigen, Inc. | Replacement Options | Black-Scholes Option-Pricing Model
Business Acquisition [Line Items]
Acquisition date fair value of replacement awards	$ 100
Apexigen, Inc. | Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	200,000
Apexigen, Inc. | Replacement Warrants
Business Acquisition [Line Items]
Number of Options, Replacement Options	5,815,613
Acquisition date fair value of replacement awards	$ 618	$ 600
Apexigen, Inc. | Replacement Warrants | Black-Scholes Option-Pricing Model
Business Acquisition [Line Items]
Acquisition date fair value of replacement awards	$ 600
Pyxis Oncology | Replacement Options
Business Acquisition [Line Items]
Number of Options, Replacement Options	712,181
Pyxis Oncology | Replacement RSUs
Business Acquisition [Line Items]
Number of Options, Replacement Options	34,500
Pyxis Oncology | Replacement Warrants
Business Acquisition [Line Items]
Number of Options, Replacement Options	1,003,191

Acquisition of Apexigen - Sched

Acquisition of Apexigen - Schedule of Supplemental Pro Forma Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Apexigen, Inc.
Business Acquisition [Line Items]
Net loss	$ (29,313)	$ (36,166)	$ (74,375)	$ (110,254)

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Carried at Fair Value on Recurring Basis (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities	$ 118,252,000	$ 0
U S Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities	118,252,000
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	128,338,000	178,751,000
Fair Value, Recurring | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	10,086,000	177,279,000
Restricted Cash		1,472,000
Fair Value, Recurring | U S Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities	118,252,000
Fair Value, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	128,338,000	178,751,000
Fair Value, Recurring | Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	10,086,000	177,279,000
Restricted Cash		$ 1,472,000
Fair Value, Recurring | Level 1 | U S Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities	$ 118,252,000

Marketable Debt Securities - Su

Marketable Debt Securities - Summary of Marketable Securities Classified as Available-for-sale (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Marketable debt securities, Amortized Cost	$ 118,357,000
Marketable debt securities, Unrealized Gains	8,000
Marketable debt securities, Unrealized Losses	(113,000)
Marketable debt securities, Aggregate Fair Value	118,252,000	$ 0
U S Treasury Securities
Debt Securities, Available-for-Sale [Line Items]
Marketable debt securities, Amortized Cost	118,357,000
Marketable debt securities, Unrealized Gains	8,000
Marketable debt securities, Unrealized Losses	(113,000)
Marketable debt securities, Aggregate Fair Value	$ 118,252,000

Marketable Debt Securities - Ad

Marketable Debt Securities - Additional Information (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Marketable debt securities at fair value	$ 118,252,000	$ 0
U S Treasury Securities
Debt Securities, Available-for-Sale [Line Items]
Marketable debt securities at fair value	$ 118,252,000

Marketable Debt Securities - In

Marketable Debt Securities - Interest and Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Interest income	$ 227	$ 719	$ 1,689	$ 892
Accretion of discount, net	1,480		3,347
Total interest and investment income	$ 1,707	$ 719	$ 5,036	$ 892

Joint Venture - Additional Info

Joint Venture - Additional Information (Details) - Voxall - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2021	Mar. 31, 2021
Schedule Of Equity Method Investments [Line Items]
Loss from equity method investment in joint venture	$ 0.1	$ 0	$ 0.1	$ 0
Promissory note issued					$ 0.2
Equity method investment, description			As the Company has no commitment to fund the losses of the equity method investment, the carrying value of the equity method investment has not been reduced below zero
Alloy Therapeutics, Inc.
Schedule Of Equity Method Investments [Line Items]
Percentage of voting membership units						50%

License Agreements - Additional

License Agreements - Additional Information (Details) - USD ($)	1 Months Ended					9 Months Ended
	Jan. 31, 2023	Mar. 31, 2022	Oct. 31, 2021	Mar. 31, 2021	Apr. 30, 2020	Sep. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Oct. 06, 2022	Sep. 30, 2022
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common stock, shares issued						44,312,767		35,110,016
Pfizer License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Payment for license fee				$ 25,000,000
Milestone and royalties required						$ 0				$ 0
Upfront payments	$ 8,000,000			$ 5,000,000
Common stock, shares issued							1,811,594		2,229,654
Pfizer License Agreement | IPO
Research And Development Arrangement Contract To Perform For Others [Line Items]
Number of common shares issued upon conversion of preferred stock			1,911,015
Pfizer License Agreement | Series B Convertible Preferred Stock
Research And Development Arrangement Contract To Perform For Others [Line Items]
Issuance of convertible preferred stock shares			12,152,145
Issuance of convertible preferred stock value			$ 20,000,000
LegoChem License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone and royalties required						0				0
Estimated cost to purchase licensed products						7,000,000
LegoChem License Agreement | Related Party
Research And Development Arrangement Contract To Perform For Others [Line Items]
Amount payable related to licensed products						0
Biosion License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone and royalties required						0				0
Biosion License Agreement | Research and Development Expenses
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront fee		$ 10,000,000
University License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common stock issued to university					48,919
Milestone and royalties required						$ 0				$ 0

Deferred Revenue - Additional I

Deferred Revenue - Additional Information (Details) - USD ($) $ in Thousands	Aug. 23, 2023	Sep. 30, 2023
Deferred Revenue Arrangement [Line Items]
Deferred revenue		$ 7,189
Apexigen, Inc. [Member]
Deferred Revenue Arrangement [Line Items]
Acqusition completed date	Aug. 23, 2023

Common Stock Warrants - Additio

Common Stock Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Aug. 23, 2023	Sep. 30, 2023	Jul. 29, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Replacement of warrants		1,003,191
Warrants redemption exercise price per share		$ 0.01
Sale price per share		$ 104.35
Consecutive trading days		20 days
Apexigen, Inc.
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Acquisition date fair value of replacement awards	$ 9,970
Replacement of warrants		5,815,613
Apexigen, Inc. | Replacement Warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Acquisition date fair value of replacement awards	$ 618	$ 600
Minimum [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Redemption notice period		30 days
Maximum [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Trading days		30 days
Warrant One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Warrants outstanding		344,259
Warrants exercise price per share		$ 8.12
Warrant Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Warrants outstanding		17,212
Warrants exercise price per share		$ 10.14
Warrant Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Warrants outstanding		641,720
Warrants exercise price per share		$ 66.67	$ 66.67

Common Stock Warrants - Summary

Common Stock Warrants - Summary of Fair Value of Replacement Warrants Black-Scholes Option Pricing Model (Details)		3 Months Ended		9 Months Ended
	Aug. 23, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected volatility, maximum		118.90%	97.34%	118.90%	101.66%
Expected volatility, minimum		98.23%	96.09%	97.11%	96.09%
Risk-free interest rate, maximum		5.57%	4.02%	5.57%	4.02%
Risk-free interest rate, minimum		4.36%	2.85%	3.58%	1.60%
Expected dividend yield		0%	0%	0%	0%
Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)		3 months	6 years	3 months	6 years
Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)		6 years 29 days	6 years 29 days	6 years 29 days	6 years 1 month 9 days
Replacement Warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected volatility	95%
Risk-free interest rate, maximum	4.50%
Risk-free interest rate, minimum	4.36%
Expected dividend yield	0%
Replacement Warrants | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	3 years 11 months 4 days
Replacement Warrants | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	4 years 11 months 8 days

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022	Nov. 14, 2022	Nov. 01, 2022
Schedule of Equity Method Investments [Line Items]
Maximum value of stock and debt instruments authorized to issue					$ 250,000
Common stock issued, value	$ 44	$ 44	$ 34
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
ATM Offering Program
Schedule of Equity Method Investments [Line Items]
Sales agents commission rate	3%	3%
Common stock, shares sold	0
ATM Offering Program | Maximum
Schedule of Equity Method Investments [Line Items]
Common stock issued, value				$ 125,000
Common Stock
Schedule of Equity Method Investments [Line Items]
Common stock issued under ATM offering program		1,001,208
Common Stock | ATM Offering Program
Schedule of Equity Method Investments [Line Items]
Gross proceeds from sale of shares		$ 6,300
Average gross sale price per share	$ 6.3	$ 6.3
Commissions paid to the placement agent		$ 200

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Reserved for Issuance (Details) - shares	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	12,781,480	10,967,643
Stock Options Outstanding
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	6,022,413	5,720,415
Unvested Restricted Stock Awards and Units
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	3,822,944	3,015,387
Stock Options Available for Issuance
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	1,348,744	1,697,166
Common Stock Warrants
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	1,003,191
Employee Stock Purchase Plan
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock reserved for future issuance	584,188	534,675

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)				3 Months Ended		9 Months Ended
	Aug. 23, 2023	Mar. 24, 2023	Jan. 01, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 29, 2023	Dec. 31, 2022	Jul. 01, 2022	Sep. 27, 2021	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance				12,781,480		12,781,480			10,967,643
Number of options to purchase common stock				6,022,413		6,022,413			5,720,415
Number of option to purchase restricted stock				3,822,944		3,822,944			3,015,387
Incremental stock-based compensation expense						$ 1,100,000
Incremental stock-based compensation expense recognized				$ 100,000		$ 900,000
Fair value of common stock per share								$ 1.99
Weighted-average fair value of options granted				$ 1.29	$ 1.9	$ 1.58	$ 3.35
Intrinsic value of options exercised				$ 100,000	$ 18,000	$ 100,000	$ 200,000
Stock options exercised						77,270
Gross unrecognized stock-based compensation expense				14,500,000		$ 14,500,000
Unrecognized stock-based compensation expense weighted average amortized period						1 year 4 months 28 days
Stock-based compensation expense				$ 2,443,000	3,157,000	$ 8,613,000	9,324,000
Apexigen
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price	$ 10,732,000
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance				3,822,944		3,822,944			3,015,387
Unrecognized stock-based compensation expense weighted average amortized period						2 years 4 months 6 days
Common stock public offering price per share				$ 0.01		$ 0.01
RSAs unvested and outstanding				18,675		18,675
Stock-based compensation expense				$ 2,700,000	$ 1,300,000	$ 5,100,000	$ 2,500,000
Gross unrecognized stock-based compensation expense				$ 8,000,000		$ 8,000,000
Replacement Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued	712,181
Replacement Options | Apexigen
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued	4,128,809
Purchase price	$ 100,000
Replacement RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued	34,500
Replacement RSUs | Apexigen
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued	200,000
Restricted Stock Units ('RSU')
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units issued						3,653,248
2022 Equity Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance										1,400,000
Number of options to purchase common stock				425,217		425,217
Number of common shares reserved for future issuance				634,814		634,814
2022 Equity Inducement Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of option to purchase restricted stock				282,067		282,067
2022 Equity Inducement Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award expiration period						10 years
2021 Equity and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance											3,852,807
Number of shares of common stock outstanding percentage						5%
Maximum number of common shares issuable under exercise of options				7,705,614		7,705,614
Number of options to purchase common stock				2,162,316		2,162,316
Number of common shares reserved for future issuance				538,035		538,035
Number of additional shares authorized			1,755,501
2021 Equity and Incentive Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of option to purchase restricted stock				2,713,673		2,713,673
2021 Equity and Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award expiration period						10 years
2019 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options to purchase common stock				2,349,850		2,349,850
Number of common shares reserved for future issuance				175,895		175,895
Reduction in exercise price of relevant option		$ 2.21
2019 Equity Incentive Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of option to purchase restricted stock				770,539		770,539
2019 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance												4,042,408
Apexigen's 2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance				443,912		443,912
Number of shares of common stock outstanding percentage						0.8625%
Maximum number of common shares issuable under exercise of options				597,077		597,077
Number of options to purchase common stock				1,085,030		1,085,030
Number of additional shares authorized						554,890
Apexigen's 2022 Equity Incentive Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of option to purchase restricted stock				37,990		37,990
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved and autorized for future issuance				584,188		584,188					424,595
Number of shares of common stock outstanding percentage						1%
Number of additional shares authorized			110,080			110,080
Number of shares issued				60,567		60,567
Stock Options 2022 Plan, 2022 EIP, 2020 EIP, 2021 Plan and 2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award expiration period						10 years
Stock options vesting period						4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Number of Options, Outstanding, Beginning Balance | shares	5,720,415
Number of Options, Granted | shares	474,725
Number of Options, Replacement Options | shares	712,181
Number of Options, Exercised | shares	(77,270)
Number of Options, Expired | shares	(305,477)
Number of Options, Forfeited | shares	(502,161)
Number of Options, Outstanding, Ending Balance | shares	6,022,413	5,720,415
Number of Options, Exercisable at September 30, 2023 | shares	3,429,701
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 9.68
Weighted Average Exercise Price, Granted | $ / shares	1.97
Weighted Average Exercise Price, Replacement Options | $ / shares	17.57
Weighted Average Exercise Price, Exercised | $ / shares	1.6
Weighted Average Exercise Price, Expired | $ / shares	11.8
Weighted Average Exercise Price, Forfeited | $ / shares	9.16
Weighted Average Exercise Price, Ending Balance | $ / shares	8.33	$ 9.68
Weighted Average Exercise Price, Exercisable at September 30, 2023 | $ / shares	$ 8.82
Weighted Average Remaining Contractual Term, Outstanding	6 years 4 months 24 days	8 years 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable	6 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding | $	$ 67	$ 72
Aggregate Intrinsic Value, Exercisable at September 30, 2023 | $	$ 52

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Fair Value Assumptions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	98.23%	96.09%	97.11%	96.09%
Expected volatility, maximum	118.90%	97.34%	118.90%	101.66%
Risk-free interest rate, minimum	4.36%	2.85%	3.58%	1.60%
Risk-free interest rate, maximum	5.57%	4.02%	5.57%	4.02%
Expected dividend yield	0%	0%	0%	0%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	3 months	6 years	3 months	6 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days	6 years 29 days	6 years 1 month 9 days

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,443	$ 3,157	$ 8,613	$ 9,324
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	775	1,623	3,122	3,190
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,668	$ 1,534	$ 5,491	$ 6,134

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Stock Activity (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning Balance | shares	3,015,387
Number of Shares, Granted | shares	3,653,248
Number of Shares, Replacement RSU Awards | shares	34,500
Number of Shares, Forfeited | shares	(654,960)
Number of Shares, Vested and settled | shares	(2,225,231)
Number of Shares, Outstanding, Ending Balance | shares	3,822,944
Weighted Average Grant ate fair value, Outstanding, Beginning Balance | $ / shares	$ 3.64
Weighted Average Grant Date Fair Value, Outstanding, Granted | $ / shares	2.18
Weighted Average Grant Date Fair Value, Outstanding, Replacement RSU Awards | $ / shares	2.3
Weighted Average Grant Date Fair Value, Outstanding, Forfeited | $ / shares	3.38
Weighted Average Grant Date Fair Value, Outstanding, Vested and settled | $ / shares	2.84
Weighted Average Grant ate fair value, Outstanding, Ending Balance | $ / shares	$ 2.63

Operating Leases - Additional I

Operating Leases - Additional Information (Details) $ in Thousands		3 Months Ended	6 Months Ended	9 Months Ended
	Feb. 02, 2023 USD ($) ft²	Sep. 30, 2023 USD ($)	Jun. 30, 2023	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Leases [Abstract]
Cash paid for operating lease liabilities				$ 1,700	$ 1,300
Sublease agreement, square feet space area in building | ft²	17,729
Sublease payment in year one	$ 1,500
Sublease payment per year thereafter	$ 1,900
Annual rent increase percentage	3%
Lessee, operating sublease, option to extend				The sublessee has the option to extend the sublease for a one-year period on the same terms and conditions as the current sublease, subject to a change in base rent for the extended period equal to a 3% increase to the then current rent.
Lessee, Operating Sublease, Existence of Option to Extend [true false]			true
Percentage of increase in current rent	3%
Security deposit	$ 400
Sublease income		$ 598		$ 1,200

Operating Leases - Components o

Operating Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating lease cost	$ 678	$ 660	$ 1,997	$ 1,392
Variable lease cost	230	12	518	116
Short-term lease cost		482	488	1,058
Total lease cost	$ 908	$ 1,154	$ 3,003	$ 2,566

Operating Leases - Weighted Ave

Operating Leases - Weighted Average Remaining Lease Term and Discount Rate (Details)	Sep. 30, 2023
Leases [Abstract]
Weighted-average remaining lease term	9 years 1 month 6 days
Weighted-average discount rate	9.40%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Effective tax rate from continuing operations	0%	0%	0%	0%
Federal income tax provision	$ 0	$ 0	$ 0	$ 0

Net Loss per Common Share - Sum

Net Loss per Common Share - Summary of Basic and Diluted Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net loss	$ (23,049)	$ (27,674)	$ (58,193)	$ (84,616)
Denominator:
Weighted average shares of common stock outstanding - basic	41,331,806	32,561,228	38,379,401	32,444,072
Weighted average shares of common stock outstanding - diluted	41,331,806	32,561,228	38,379,401	32,444,072
Net loss per common share - basic	$ (0.56)	$ (0.85)	$ (1.52)	$ (2.61)
Net loss per common share - diluted	$ (0.56)	$ (0.85)	$ (1.52)	$ (2.61)

Net Loss per Common Share - Ant

Net Loss per Common Share - Anti-Dilutive Effect Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	12,781,480	11,076,553
Stock Options Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	6,022,413	5,835,740
Unvested Restricted Stock Awards and Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	3,822,944	3,124,325
Stock Options Available for Issuance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	1,348,744	1,581,813
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	1,003,191
Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive effect excluded from computation of diluted net loss per share attributable to common stockholders	584,188	534,675

Related Parties - Additional In

Related Parties - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pfizer License Agreement
Related Party Transaction [Line Items]
Ownership percentage	10%		10%
Related Party | Pfizer License Agreement
Related Party Transaction [Line Items]
Related party transaction expenses incurred	$ 0	$ 0	$ 0	$ 0
Related Party | Voxall
Related Party Transaction [Line Items]
Related party transaction expenses incurred	0	0	0	0
University License Agreement | Related Party
Related Party Transaction [Line Items]
Related party transaction expenses incurred	$ 0	$ 0	$ 0	$ 0

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - Subsequent Event $ in Millions	Nov. 07, 2023 USD ($)
Subsequent Event [Line Items]
Percentage of workforce reduction of current employees	40%
Workforce reduction cost	$ 1.4