BioAtla (BCAB) 10-Q 4 Nov 22 2022 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 02, 2022
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Entity File Number	001-39787
Entity Registrant Name	BIOATLA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-1922320
Entity Address, Address Line One	11085 Torreyana Road
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	558-0708
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	BCAB
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001826892
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,211,959
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		36,395,338

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 178,120	$ 244,979
Prepaid expenses and other current assets	5,189	2,313
Total current assets	183,309	247,292
Property and equipment, net	3,002	3,676
Operating lease right-of-use asset, net	2,647	3,300
Other assets	154	154
Total assets	189,112	254,422
Current liabilities:
Accounts payable and accrued expenses	22,327	18,424
Operating lease liabilities	1,498	1,389
Total current liabilities	23,825	19,813
Operating lease liabilities, less current portion	2,847	3,982
Liability to licensor	19,806	19,806
Total liabilities	46,478	43,601
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 200,000,000 shares authorized at September 30, 2022 and December 31, 2021; 0 shares issued and outstanding at September 30, 2022 and December 31, 2021	0	0
Common stock value	4	4
Additional paid-in capital	407,888	397,136
Accumulated deficit	(265,258)	(186,319)
Total stockholders’ equity	142,634	210,821
Total liabilities and stockholders’ equity	189,112	254,422
Class B Common Stock
Stockholders’ equity:
Common stock value

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	200,000,000	200,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	350,000,000	350,000,000
Common stock, shares issued (in shares)	36,365,317	35,799,233
Common stock, shares outstanding (in shares)	36,365,317	35,799,233
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	15,368,569	15,368,569
Common stock, shares issued (in shares)	1,211,959	1,492,059
Common stock, shares outstanding (in shares)	1,211,959	1,492,059

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Collaboration and other revenue				$ 250
Operating expenses:
Research and development expense	19,839	16,553	57,473	41,826
General and administrative expense	6,340	7,142	22,107	31,376
Total operating expenses	26,179	23,695	79,580	73,202
Loss from operations	(26,179)	(23,695)	(79,580)	(72,952)
Other income (expense):
Interest income	370	76	601	254
Interest expense				(3)
Gain on extinguishment of long-term debt		690		690
Other income (expense)	30	(1)	40	(1)
Total other income (expense)	400	765	641	940
Consolidated net loss and comprehensive loss	$ (25,779)	$ (22,930)	$ (78,939)	$ (72,012)
Net loss per common share, basic	$ (0.69)	$ (0.68)	$ (2.11)	$ (2.13)
Net loss per common share, diluted	$ (0.69)	$ (0.68)	$ (2.11)	$ (2.13)
Weighted-average shares of common stock outstanding, basic	37,516,769	33,909,460	37,420,531	33,751,558
Weighted-average shares of common stock outstanding, diluted	37,516,769	33,909,460	37,420,531	33,751,558

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Class B Common Stock	Common Stock	Additional Paid-In Capital	Accumulate Deficit
Beginning balance at Dec. 31, 2020	$ 209,974		$ 3	$ 300,888	$ (90,917)
Beginning balance, share at Dec. 31, 2020		1,492,059	32,171,560
Stock-based compensation expense	21,307			21,307
Issuance of common stock under equity incentive plans, share			327,241
Issuance of common stock for Employee Stock Purchase Plan	190			190
Issuance of common stock for Employee Stock Purchase Plan, shares			5,280
Issuance of common stock upon exercise of options, net, shares			7,747
Issuance of common stock upon exercise of options, net	140			140
Issuance of common stock, net of issuance costs, shares			2,678,600
Issuance of common stock, net of issuance costs	71,054		$ 1	71,053
Net loss	(72,012)				(72,012)
Ending balance at Sep. 30, 2021	230,653		$ 4	393,578	(162,929)
Ending balance, share at Sep. 30, 2021		1,492,059	35,190,428
Beginning balance at Jun. 30, 2021	178,023		$ 3	318,019	(139,999)
Beginning balance, share at Jun. 30, 2021		1,492,059	32,315,301
Stock-based compensation expense	4,366			4,366
Issuance of common stock under equity incentive plans, share			188,780
Issuance of common stock upon exercise of options, net, shares			7,747
Issuance of common stock upon exercise of options, net	140			140
Issuance of common stock, net of issuance costs, shares			2,678,600
Issuance of common stock, net of issuance costs	71,054		$ 1	71,053
Net loss	(22,930)				(22,930)
Ending balance at Sep. 30, 2021	230,653		$ 4	393,578	(162,929)
Ending balance, share at Sep. 30, 2021		1,492,059	35,190,428
Beginning balance at Dec. 31, 2021	210,821		$ 4	397,136	(186,319)
Beginning balance, share at Dec. 31, 2021		1,492,059	35,799,233
Stock-based compensation expense	11,062			11,062
Issuance of common stock for Employee Stock Purchase Plan	19			19
Issuance of common stock for Employee Stock Purchase Plan, shares			9,482
Taxes related to net share settlement of equity awards	(329)			(329)
Conversion of Class B common stock, shares		(280,100)	280,100
Issuance of common stock under equity incentive plans, net of shares withheld for taxes, shares			276,502
Net loss	(78,939)				(78,939)
Ending balance at Sep. 30, 2022	142,634		$ 4	407,888	(265,258)
Ending balance, share at Sep. 30, 2022		1,211,959	36,365,317
Beginning balance at Jun. 30, 2022	164,952		$ 4	404,427	(239,479)
Beginning balance, share at Jun. 30, 2022		1,492,059	35,993,458
Stock-based compensation expense	3,588			3,588
Taxes related to net share settlement of equity awards	(127)			(127)
Conversion of Class B common stock, shares		(280,100)	280,100
Issuance of common stock under equity incentive plans, net of shares withheld for taxes, shares			91,759
Net loss	(25,779)				(25,779)
Ending balance at Sep. 30, 2022	$ 142,634		$ 4	$ 407,888	$ (265,258)
Ending balance, share at Sep. 30, 2022		1,211,959	36,365,317

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net loss	$ (78,939)	$ (72,012)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	901	1,016
Loss on disposal of property and equipment	6	4
Gain on extinguishment of debt		(690)
Stock-based compensation	11,062	21,307
Accrued interest		3
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,876)	(1,516)
Accounts payable and accrued expenses	4,146	10,844
Right-of-use assets and lease liabilities, net	(373)	(221)
Net cash used in operating activities	(66,073)	(41,265)
Cash flows from investing activities
Purchases of property and equipment	(237)	(835)
Proceeds from sale of property and equipment	3
Net cash used in investing activities	(234)	(835)
Cash flows from financing activities
Payment of initial public offering costs		(1,911)
Proceeds from issuance of common stock		75,001
Proceeds from exercise of stock options		140
Proceeds from issuance of common stock under Employee Stock Purchase Plan	19	190
Payments for taxes related to net settlement of equity awards	(571)
Net cash provided by (used in) financing activities	(552)	73,420
Net increase (decrease) in cash and cash equivalents	(66,859)	31,320
Cash and cash equivalents, beginning of period	244,979	238,605
Cash and cash equivalents, end of period	178,120	269,925
Supplemental disclosure of non-cash investing and financing activities
Property and equipment additions included in accounts payable and accrued expenses	1	8
Equity issuance costs included in accounts payable and accrued expenses		3,947
Tax related to net settlement of equity awards included in accounts payable and accrued expenses	$ 49

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies Organization BioAtla, LLC was formed in Delaware in March 2007 and, after undergoing two separate reorganizations in 2019 and in 2020, was converted to a Delaware corporation in July 2020 and was renamed BioAtla, Inc. (the “Company”). The Company has a proprietary platform for creating biologics, including its conditionally active biologics (“CAB” or “CABs”). CABs have been designed to be active only under certain conditions found in diseased tissue, while remaining inactive in normal tissue. The Company is currently in clinical development of its two lead CAB antibody drug conjugates (“CAB ADC”) targeting AXL and ROR2 receptors, and its CAB immune-oncology antibody targeting CTLA-4. Basis of Presentation and Principles of Consolidation Prior to the reorganization in July 2020 (or "Corporate Reorganization"), the consolidated financial statements included the accounts of BioAtla, LLC and those of its majority owned subsidiary Himalaya Therapeutics SEZC that had no material operations. Himalaya Therapeutics SEZC also had a wholly owned subsidiary, Himalaya Therapeutics HK Limited that had no material operations. All intercompany balances were eliminated in consolidation. In connection with the Corporate Reorganization, Himalaya Therapeutics SEZC and Himalaya Therapeutics HK Limited were deconsolidated without material impact to the consolidated financial statements. Subsequent to the Corporate Reorganization, BioAtla, Inc. became a single legal entity with no consolidated variable interest entities ("VIEs") or subsidiaries. The unaudited condensed consolidated financial statements as of September 30, 2022, and for the three and nine months ended September 30, 2022 and 2021, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”), and with accounting principles generally accepted in the United States (“GAAP”) applicable to interim financial statements. These unaudited condensed consolidated financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year or future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021 , included in its Annual Report on Form 10-K filed with the SEC on February 28, 2022. Liquidity and Going Concern The Company has incurred cumulative operating losses and negative cash flows from operations since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future as it continues the development of its product candidates. As of September 30, 2022, the Company had an accumulated deficit of $ 265.3 million . The Company plans to continue to fund its losses from operations and capital funding needs through public or private equity or debt financings 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. Management is required to perform a two-step analysis of the Company’s ability to continue as a going concern. Management must first evaluate whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern (Step 1). If management concludes that substantial doubt is raised, management is also required to consider whether its plans alleviate that doubt (Step 2). Management’s assessment included the preparation of cash flow forecasts resulting in management’s conclusion that there is not substantial doubt about the Company’s ability to continue as a going concern as its current cash and cash equivalents will be sufficient to fund the Company’s operations for a period of at least one year from the issuance date of these unaudited condensed consolidated financial statements. Use of Estimates The preparation of the Company’s condensed consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes. The most significant estimates in the Company’s condensed consolidated financial statements relate to revenue recognition, accruals for research and development costs, and equity-based compensation. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of revenue and expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected. Concentrations of Risk Financial instruments that potentially subject the Company to a significant concentration of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Stock-Based Compensation Stock-based compensation expense represents the grant date fair value of equity awards, consisting of stock options, restricted stock units (“RSUs”) and employee stock purchase plan rights, over the requisite service period of the awards (usually the vesting period) on a straight-line basis. The Company estimates the fair value of stock option grants and employee stock purchase plan rights using the Black-Scholes option pricing model. Prior to the Company’s IPO, the fair value of RSUs was based on the estimated fair value of the underlying common stock on the date of grant and, subsequent to the Company’s IPO, the fair value is based on the closing sales price of the Company’s common stock on the date of grant. Equity award forfeitures are recognized as they occur. Leases The Company determines if an arrangement is a lease at inception. An arrangement is or contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. If a lease is identified, classification is determined at lease commencement. Operating lease liabilities are recognized at the present value of the future lease payments at the lease commencement date. The Company’s leases do not provide an implicit interest rate and therefore the Company estimates its incremental borrowing rate to discount lease payments. The incremental borrowing rate reflects the interest rate that the Company would have to pay to borrow on a collateralized basis an amount equal to the lease payments in a similar economic environment over a similar term. Operating lease right-of-use (“ROU”) assets are based on the corresponding lease liability adjusted for any lease payments made at or before commencement, initial direct costs, and lease incentives. Renewals or early terminations are not accounted for unless the Company is reasonably certain to exercise these options. Operating lease expense is recognized and the ROU asset is amortized on a straight-line basis over the lease term. Variable lease costs are not included in the calculation of the ROU asset and the related lease liability and are recognized as incurred. The Company has a single lease agreement with lease and non-lease components, which are accounted for as a single lease component. Payments for short-term leases, defined as leases with a term of twelve months or less, are expensed on a straight-line basis over the lease term. The Company does not currently have any short-term leases. Operating leases are included in operating lease right-of-use assets, operating lease liabilities, and operating lease liabilities, non-current on the Company’s consolidated balance sheets. The Company does not have any finance leases. Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss. Net Loss Per Share Basic net loss per common share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of RSUs, common stock options outstanding under the Company’s stock option plan, and contingently issuable shares under the Company's ESPP plan. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalents): Nine Months Ended 2022 2021 Common stock warrants — 717,674 Common stock options 2,718,930 960,402 Restricted stock units 629,007 1,592,796 ESPP shares 115,783 4,109 Total 3,463,720 3,274,981 Recent Accounting Pronouncements There were no new accounting standards that had a material impact on the Company’s consolidated financial statements during the three or nine months ended September 30, 2022, and there were no other new accounting standards or pronouncements that were issued but not yet effective as of September 30, 2022 that the Company expects to have a material impact on its consolidated financial statements.

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	2. Balance Sheet Details Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, Prepaid research and development $ 3,978 $ 1,811 Prepaid insurance 692 — Other prepaid expenses and current assets 519 502 Total $ 5,189 $ 2,313 Property and equipment consist of the following (in thousands): Useful life September 30, December 31, Furniture, fixtures and office equipment 3 - 7 $ 2,192 $ 2,123 Laboratory equipment 5 2,265 2,123 Leasehold improvements 2 - 3 3,687 3,687 8,144 7,933 Less accumulated depreciation and amortization ( 5,142 ) ( 4,257 ) Total $ 3,002 $ 3,676 Accounts payable and accrued expenses consist of the following (in thousands): September 30, December 31, Accounts payable $ 3,696 $ 1,179 Accrued compensation 2,979 2,671 Accrued research and development 14,713 13,501 Other accrued expenses 939 1,073 Total $ 22,327 $ 18,424

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The carrying amounts of the Company’s current financial assets and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. As of September 30, 2022 and December 31, 2021 , the Company had no financial assets or liabilities measured at fair value on a recurring basis. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. None of the Company’s non-financial assets and liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented.

Debt

Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Debt	4. Debt The Company did no t have any outstanding debt as of September 30, 2022 or December 31, 2021. In April 2020, the Company borrowed $ 0.7 million under the Paycheck Protection Program (“PPP”) under the CARES Act. The loan was subsequently forgiven in July 2021. The $ 0.7 million balance of the forgiven loan was recognized as other income on the Company's Statement of Operations for the three and nine months ended September 30, 2021. For the three and nine months ended September 30, 2021, the Company recognized interest expense related to its outstanding debt of $ 0 and $ 3,000 , respectively.

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Leases	5. Leases The Company has a single operating lease for its corporate headquarters and laboratory space in San Diego, California. The lease expires in July 2025 and the Company has an option to extend the term of the lease for an additional five years . Additionally, the lease includes certain rent abatement, rent escalations, tenant improvement allowances and additional charges for common area maintenance and other costs. The components of lease expense included in the Company’s condensed consolidated statements of operations include (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease expense $ 261 $ 261 $ 782 $ 782 Variable lease expense 132 128 328 384 Total lease expense, net $ 393 $ 389 $ 1,110 $ 1,166 Variable lease costs are primarily related to payments made to lessors for common area maintenance, property taxes, insurance, and other operating expenses. The Company did not have any short-term leases or finance leases for the three and nine months ended September 30, 2022 and 2021, respectively. The weighted average remaining lease term and weighted average discount rate for operating leases were as follows: As of September 30, 2022 2021 Weighted average remaining lease term (in years) 2.75 3.75 Weighted average discount rate percentage 3.50 % 3.50 % Supplemental cash flow information related to leases under which the Company is the lessee was as follows (amounts in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cash paid for amounts included in the measurement of operating leases $ 401 $ 370 $ 1,155 $ 1,003 As of September 30, 2022, future minimum payments under the Company's non-cancelable operating lease under ASC 842 were as follows (in thousands): Operating Three months ending December 31, 2022 $ 401 2023 1,636 2024 1,685 2025 845 Thereafter — Total future lease payments 4,567 Less: imputed interest ( 222 ) Total operating lease liabilities $ 4,345

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies From time to time, the Company may be subject to various claims and suits arising in the ordinary course of business. The Company is not currently a party to any legal proceedings the outcome of which the Company believes, if determined adversely to the Company, would individually or in the aggregate have a material adverse effect on the Company’s business, operating results or financial condition.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity 2020 Equity Incentive Plan The Company may grant awards of common stock under the 2020 Equity Incentive Plan (the "2020 Plan") to the Company’s employees, consultants and non-employee directors pursuant to option awards, stock appreciation rights awards, restricted stock awards, restricted stock unit awards, performance stock awards, performance stock unit awards and other stock-based awards. As of September 30, 2022 and December 31, 2021 , the total number of common shares authorized for issuance under the 2020 Plan was 7,658,509 and 6,226,540 , respective ly. On January 1st of each year, commencing with the first January 1st following the effective date of the 2020 Plan, the shares authorized for issuance under the 2020 Plan shall be increased by a number of shares equal to the lesser of 4% of the total number of shares outstanding on the immediately preceding December 31st and such lesser number of shares determined by the Company’s board of directors. The maximum term of the options granted under the 2020 Plan is no more than ten years. Awards under the 2020 Plan generally vest at 25 % one year from the vesting commencement date and ratably each month thereafter for a period of 36 months , subject to continuous service. Stock-based compensation expense for the three and nine months ended September 30, 2022 and 2021 has been reported in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended Nine Months Ended 2022 2021 2022 2021 Research and development $ 1,427 $ 1,267 $ 4,125 $ 3,376 General and administrative 2,161 3,099 6,937 17,931 Total $ 3,588 $ 4,366 $ 11,062 $ 21,307 Restricted Stock Units The following table summarizes RSU activity under the 2020 Plan for the nine months ended September 30, 2022: Number of Weighted - Average Outstanding at December 31, 2021 975,046 $ 18.00 Granted — $ — Vested ( 335,305 ) $ 18.00 Forfeited ( 10,734 ) $ 18.00 Outstanding at September 30, 2022 629,007 $ 18.00 As of September 30, 2022, total unrecognized stock-based compensation expense for RSUs was $ 11.3 million , which is expected to be recognized over a remaining weighted-average period of approximately 1.5 years . During the nine months ended September 30, 2021, the Company modified 138,461 RSU's under the Transition Agreement (See Note 9). Stock Options The following table summarizes stock option activity under the 2020 Plan for the nine months ended September 30, 2022: Number of Weighted - Average Weighted -Average Aggregate Balance at December 31, 2021 1,086,902 $ 26.76 9.22 $ 991,495 Granted 1,667,200 $ 6.29 Exercised — $ — Forfeited ( 19,708 ) $ 26.95 Expired ( 15,464 ) $ 39.12 Balance at September 30, 2022 2,718,930 $ 14.00 9.06 $ 2,733,693 Vested and expected to vest at September 30, 2022 2,718,930 $ 14.00 9.06 $ 2,733,693 Exercisable at September 30, 2022 408,742 $ 26.18 8.34 $ — As of September 30, 2022 , total unrecognized stock-based compensation cost for unvested common stock options was $ 16.4 million, which is expected to be recognized over a remaining weighted-average period of approximately 3.1 years. The weighted- average grant date fair value of stock options granted during the nine months ended September 30, 2022 was $ 4.01 per share. The total fair value of options vested during the nine months ended September 30, 2022 was $ 5.4 million. During the nine months ended September 30, 2021 the Company modified 7,747 stock options under the Transition Agreement (See Note 9). The assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants were as follows: Nine Months Ended 2022 2021 Expected volatility 74.8 % 74.7 % Risk-free interest rate 2.09 % 0.99 % Expected dividend yield 0.0 % 0.0 % Expected term 6.04 5.86 Expected volatility. As the Company’s common stock does not have a significant trading history, the expected volatility assumption is based on volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. Risk-free interest rate. The Company bases the risk-free interest rate assumption on the U.S. Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. Expected dividend yield. The Company bases the expected dividend yield assumption on the fact that it has never paid cash dividends and has no present plans to pay cash dividends. Expected term. For employees, the expected term represents the period of time that options are expected to be outstanding. Because the Company has minimal historical exercise behavior, it determines the expected life assumption using the simplified method, which is an average of the contractual term of the option and its vesting period. For nonemployees, the expected term is generally the contractual term of the option. Employee Stock Purchase Plan The BioAtla, Inc. Employee Stock Purchase Plan (the “ESPP”) permits participants to purchase common stock through payroll deductions of up to 15 % of their eligible compensation. As of September 30, 2022 and December 31, 2021, a total of 1,229,148 shares and 833,993 shares, respectively, of common stock were authorized for issuance under the ESPP. The number of shares of common stock authorized for issuance will automatically increase on January 1 of each calendar year, from January 1, 2021 through January 1, 2030 by the least of (i) 1.0 % of the total number of common shares of our common stock outstanding on December 31 of the preceding calendar year (calculated on a fully diluted basis), (ii) 929,658 common shares or (iii) a number determined by the Company’s board of directors that is less than (i) and (ii). In February 2021, employees began to enroll in the ESPP and the Company’s first offering period commenced. The Company issued 9,482 common shares under the ESPP during the nine months ended September 30, 2022. Comparatively, the Company issued 5,280 common shares under the ESPP during the nine months ended September 30, 2021. As of September 30, 2022, 1,208,484 shares o f common stock remained available for issuance under the ESPP. Stock-based compensation expense related to the ESPP for the three and nine months ended September 30, 2022 and 2021 was immaterial. Common Stock Warrants The Company issued warrants in 2016 in connection with certain advisory services. The warrants became exercisable upon our IPO for a period of 365 and 450 days. Upon adoption of ASU No. 2018-07 on October 1, 2020, the measurement date of the warrants became fixed in accordance with the guidance, and such fair value was nominal since the warrants were deeply out-of-the-money. In December 2021, a total of 566,586 warrants with an exercise period of 365 days after our IPO expired unexercised. The remaining 151,088 warrants with an exercise period of 450 days after the Company's IPO expired unexercised in March 2022. Accordingly, there are no remaining common stock warrants outstanding and exercisable at September 30, 2022. Common Stock Reserved for Future Issuance Common stock reserved for future issuance are as follows in common equivalent shares: September 30, December 31, Warrants for the purchase of common stock — 151,088 Common stock options and restricted stock units issued and outstanding 3,347,937 2,061,948 Awards available for future issuance under the 2020 Plan 3,022,529 3,211,854 Awards available for future issuance under the ESPP 1,208,484 822,811 Total common stock reserved for future issuance 7,578,950 6,247,701

Collaboration, License and Opti

Collaboration, License and Option Agreements	9 Months Ended
	Sep. 30, 2022
Collaboration License And Option Agreements [Abstract]
Collaboration, License and Option Agreements	8. Collaboration, License and Option Agreements BeiGene In April 2019, the Company entered into a Global Co-Development and Collaboration agreement (the “BeiGene Collaboration”) with BeiGene, Ltd. and BeiGene Switzerland GmbH (collectively “BeiGene”), a commercial-stage biopharmaceutical company, for the development, manufacturing and commercialization of the Company’s investigational CAB CTLA-4 antibody (BA3071). The Company and BeiGene amended the Global Co-Development and Collaboration agreement in December 2019 and in October 2020 (the “Amended BeiGene Collaboration”). In 2019, the Company received a total of $ 25.0 million in non-refundable payments from BeiGene. Under the terms of the Amended BeiGene Collaboration, BeiGene was generally responsible for developing BA3071 and for global regulatory filings and commercialization. Subject to the terms of the Amended BeiGene Collaboration, BeiGene held an exclusive license with the Company to develop and manufacture the BA3071 candidate globally, and BeiGene was responsible for all costs of development, manufacturing and commercialization globally. The Amended BeiGene Collaboration provided that the Company was eligible to receive tiered royalties on sales worldwide, subsequent development and regulatory milestone payments globally and commercial milestones in the BeiGene territory. On November 18, 2021, the Company entered into Amendment No. 3 to the Amended BeiGene Collaboration (“Amendment No.3”). Under Amendment No. 3, the Amended BeiGene Collaboration was terminated, subject to survival of certain provisions, and the Company regained the rights to know-how and materials under the Amended BeiGene Collaboration and assumed responsibility for the global development and commercialization of BA3071. As consideration for Amendment No.3, the Company agreed to pay BeiGene mid-single digit royalties on sales worldwide and on a limited basis will share in any upfront and milestone payments received through a sublicense of BA3071. As part of Amendment No.3, the Company reclassified its remaining $ 19.8 million of deferred revenue as a long-term liability which is expected to settle as licensing payments are made to BeiGene in accordance with the resulting amendment. In the event the license is terminated, the liability will be extinguished with no further payment to BeiGene. For the three and nine months ended September 30, 2022 and 2021 , the Company did no t recognize any revenue related to the collaboration agreement with BeiGene. As of September 30, 2022 and December 31, 2021 , the Company had a $ 19.8 million Liability to Licensor, and $ 19.8 million of deferred revenue which was classified as current, respectively. Service Contracts Prior to developing its own programs, the Company entered into various fixed price research service contracts. In connection with those service contracts, the Company may receive future milestone payments if certain clinical, regulatory and commercialization milestones are achieved. The Company is also eligible to receive royalties based on certain product sales. The Company recognized revenue of $ 0.3 million, included in “Collaboration and Other Revenue”, for the nine months ended September 30, 2021 related to the achievement of a clinical milestone on a fixed price service contract. The Company did no t recognize any revenue related to its legacy service contracts during the three or nine months ended September 30, 2022. BMS Collaboration In January 2022, the Company entered into a Master Clinical Trial Collaboration Agreement (the “BMS Collaboration”) with Bristol-Myers Squibb Company (“BMS”) pursuant to which the Company and BMS will investigate the Company’s CAB-ADC candidates, mecbotamab vedotin (BA3011) and ozuriftamab vedotin (BA3021), each in combination with Opdivo (the “BMS Compound”) in clinical trials (each a “Combined Therapy Study”). Opdivo has received approval for several anti-cancer indications. Under the BMS Collaboration, the Company will serve as the study sponsor for each Combined Therapy Study and will be responsible for the costs associated with trial execution. BMS will supply the Company with clinical drug supply of the BMS Compound at no cost to the Company for each study as well as provide input on certain clinical and regulatory aspects of each Combined Therapy Study in exchange for jointly owning clinical data. The BMS collaboration may be early terminated if a party is in material breach, if either party files for bankruptcy, or due to the existence of a material safety issue. Subject to earlier termination, the BMS Collaboration shall remain in effect until completion and delivery of final study documents for each of the Combined Therapy Study to both parties. Himalaya Therapeutics Exclusive Rights Agreement On January 1, 2020, the Company entered into an Amended and Restated Exclusive Rights Agreement (the “Amended Rights Agreement”) with Himalaya Therapeutics SEZC. Under the terms of the Amended Rights Agreement, Himalaya Therapeutics SEZC acquired the rights to 10 CAB-antibodies for the territory of China, Macao, Hong Kong and Taiwan with future rights to 2 or more CAB-antibodies, global rights to a CAB-HER2-bispecific-antibody and global co-development rights with us to an IL-22 non-CAB-antibody. Payments to the Company may include upfront payments, milestone payments and double-digit royalties, which represent a variable interest held by the Company, but no payments have been made to the Company to date. Himalaya Therapeutics SEZC is a related party.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related party transactions	9. Related Party Transactions Carolyn Anderson Short Transition Agreement On March 23, 2021, the Company entered into a transition agreement with Ms. Anderson Short, our Co-founder and Executive Vice President and Chief of Intellectual Property and Strategy at that time. Pursuant to this transition agreement, Ms. Anderson Short continued in her role with the same base salary and employee benefits until her employment with the Company was terminated on May 31, 2021. Upon her separation from the Company and subject to her execution of a release of claims, Ms. Anderson Short received the following severance benefits as set forth in the transition agreement, which satisfied existing severance obligations owing to her under a legacy pre-IPO severance agreement she had entered into with the Company on July 1, 2018: (i) a lump sum payment equal to 18 months of Ms. Anderson Short’s then-current base salary, (ii) a payment at her targeted bonus rate for 2021, pro-rated to the date of her termination of employment, and (iii) full accelerated vesting of her equity awards including 7,747 stock options and 138,461 restricted stock units. The modification of these equity awards resulted in an incremental fair value of $ 7.0 million which was recognized on a straight-line basis over the transition service period which ended on the separation date. For the three and nine months ended September 30, 2021 , the Company recognized $ 0 and $ 1.0 million, respectively, related to the lump sum salary payment and target bonus. The Company also recognized non-cash stock-based compensation charges of $ 0 and $ 9.4 million related to the modified equity awards for the three and nine months ended September 30, 2021 , respectively. No unrecognized stock-based compensation remained as of September 30, 2021. Himalaya Therapeutics Clinical Trial Agreement In April 2022, the Company entered into a Clinical Trial Agreement with Himalaya Therapeutics SEZC. Under the agreement, Himalaya Therapeutics SEZC agreed to provide services related to the initiation of clinical trials for BA3011 in the People’s Republic of China. For the first year following effectiveness of the agreement, the Company has agreed to pay Himalaya Therapeutics SEZC for the full-time use of two of its personnel. Payments are due and payable by BioAtla to Himalaya Therapeutics SEZC on a quarterly calendar basis and are non-refundable. For the three and nine months ended September 30, 2022 the Company recognized $ 0.1 million in research and development expense related to the Clinical Trial Agreement. The Company did not have any amounts due from or due to Himalaya Therapeutics SEZC as of September 30, 2022 .

401(k) Plan

401(k) Plan	9 Months Ended
	Sep. 30, 2022
Retirement Benefits [Abstract]
401(k) Plan	10. 401(k) Plan The Company maintains a defined contribution 401(k) plan available to eligible employees. Employee contributions are voluntary and are determined on an individual basis, limited to the maximum amount allowable under federal tax regulations. The Company, at its discretion, may make certain matching contributions to the 401(k) plan. As of September 30, 2022 and December 31, 2021 , the Company had no t made any matching contributions.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Organization	Organization BioAtla, LLC was formed in Delaware in March 2007 and, after undergoing two separate reorganizations in 2019 and in 2020, was converted to a Delaware corporation in July 2020 and was renamed BioAtla, Inc. (the “Company”). The Company has a proprietary platform for creating biologics, including its conditionally active biologics (“CAB” or “CABs”). CABs have been designed to be active only under certain conditions found in diseased tissue, while remaining inactive in normal tissue. The Company is currently in clinical development of its two lead CAB antibody drug conjugates (“CAB ADC”) targeting AXL and ROR2 receptors, and its CAB immune-oncology antibody targeting CTLA-4.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation Prior to the reorganization in July 2020 (or "Corporate Reorganization"), the consolidated financial statements included the accounts of BioAtla, LLC and those of its majority owned subsidiary Himalaya Therapeutics SEZC that had no material operations. Himalaya Therapeutics SEZC also had a wholly owned subsidiary, Himalaya Therapeutics HK Limited that had no material operations. All intercompany balances were eliminated in consolidation. In connection with the Corporate Reorganization, Himalaya Therapeutics SEZC and Himalaya Therapeutics HK Limited were deconsolidated without material impact to the consolidated financial statements. Subsequent to the Corporate Reorganization, BioAtla, Inc. became a single legal entity with no consolidated variable interest entities ("VIEs") or subsidiaries. The unaudited condensed consolidated financial statements as of September 30, 2022, and for the three and nine months ended September 30, 2022 and 2021, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”), and with accounting principles generally accepted in the United States (“GAAP”) applicable to interim financial statements. These unaudited condensed consolidated financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year or future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021 , included in its Annual Report on Form 10-K filed with the SEC on February 28, 2022.
Liquidity and Going Concern	Liquidity and Going Concern The Company has incurred cumulative operating losses and negative cash flows from operations since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future as it continues the development of its product candidates. As of September 30, 2022, the Company had an accumulated deficit of $ 265.3 million . The Company plans to continue to fund its losses from operations and capital funding needs through public or private equity or debt financings 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. Management is required to perform a two-step analysis of the Company’s ability to continue as a going concern. Management must first evaluate whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern (Step 1). If management concludes that substantial doubt is raised, management is also required to consider whether its plans alleviate that doubt (Step 2). Management’s assessment included the preparation of cash flow forecasts resulting in management’s conclusion that there is not substantial doubt about the Company’s ability to continue as a going concern as its current cash and cash equivalents will be sufficient to fund the Company’s operations for a period of at least one year from the issuance date of these unaudited condensed consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of the Company’s condensed consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes. The most significant estimates in the Company’s condensed consolidated financial statements relate to revenue recognition, accruals for research and development costs, and equity-based compensation. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of revenue and expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject the Company to a significant concentration of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense represents the grant date fair value of equity awards, consisting of stock options, restricted stock units (“RSUs”) and employee stock purchase plan rights, over the requisite service period of the awards (usually the vesting period) on a straight-line basis. The Company estimates the fair value of stock option grants and employee stock purchase plan rights using the Black-Scholes option pricing model. Prior to the Company’s IPO, the fair value of RSUs was based on the estimated fair value of the underlying common stock on the date of grant and, subsequent to the Company’s IPO, the fair value is based on the closing sales price of the Company’s common stock on the date of grant. Equity award forfeitures are recognized as they occur.
Leases	Leases The Company determines if an arrangement is a lease at inception. An arrangement is or contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. If a lease is identified, classification is determined at lease commencement. Operating lease liabilities are recognized at the present value of the future lease payments at the lease commencement date. The Company’s leases do not provide an implicit interest rate and therefore the Company estimates its incremental borrowing rate to discount lease payments. The incremental borrowing rate reflects the interest rate that the Company would have to pay to borrow on a collateralized basis an amount equal to the lease payments in a similar economic environment over a similar term. Operating lease right-of-use (“ROU”) assets are based on the corresponding lease liability adjusted for any lease payments made at or before commencement, initial direct costs, and lease incentives. Renewals or early terminations are not accounted for unless the Company is reasonably certain to exercise these options. Operating lease expense is recognized and the ROU asset is amortized on a straight-line basis over the lease term. Variable lease costs are not included in the calculation of the ROU asset and the related lease liability and are recognized as incurred. The Company has a single lease agreement with lease and non-lease components, which are accounted for as a single lease component. Payments for short-term leases, defined as leases with a term of twelve months or less, are expensed on a straight-line basis over the lease term. The Company does not currently have any short-term leases. Operating leases are included in operating lease right-of-use assets, operating lease liabilities, and operating lease liabilities, non-current on the Company’s consolidated balance sheets. The Company does not have any finance leases.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss.
Net Loss Per Share	Net Loss Per Share Basic net loss per common share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of RSUs, common stock options outstanding under the Company’s stock option plan, and contingently issuable shares under the Company's ESPP plan. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalents): Nine Months Ended 2022 2021 Common stock warrants — 717,674 Common stock options 2,718,930 960,402 Restricted stock units 629,007 1,592,796 ESPP shares 115,783 4,109 Total 3,463,720 3,274,981
Recent Accounting Pronouncements	Recent Accounting Pronouncements There were no new accounting standards that had a material impact on the Company’s consolidated financial statements during the three or nine months ended September 30, 2022, and there were no other new accounting standards or pronouncements that were issued but not yet effective as of September 30, 2022 that the Company expects to have a material impact on its consolidated financial statements.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Schedule of Anti-dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalents): Nine Months Ended 2022 2021 Common stock warrants — 717,674 Common stock options 2,718,930 960,402 Restricted stock units 629,007 1,592,796 ESPP shares 115,783 4,109 Total 3,463,720 3,274,981

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule Of Prepaid Expenses Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, Prepaid research and development $ 3,978 $ 1,811 Prepaid insurance 692 — Other prepaid expenses and current assets 519 502 Total $ 5,189 $ 2,313
Schedule of Property and Equipment	Property and equipment consist of the following (in thousands): Useful life September 30, December 31, Furniture, fixtures and office equipment 3 - 7 $ 2,192 $ 2,123 Laboratory equipment 5 2,265 2,123 Leasehold improvements 2 - 3 3,687 3,687 8,144 7,933 Less accumulated depreciation and amortization ( 5,142 ) ( 4,257 ) Total $ 3,002 $ 3,676
Schedule of Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consist of the following (in thousands): September 30, December 31, Accounts payable $ 3,696 $ 1,179 Accrued compensation 2,979 2,671 Accrued research and development 14,713 13,501 Other accrued expenses 939 1,073 Total $ 22,327 $ 18,424

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Lessee Disclosure [Abstract]
Components of Lease Expense	The components of lease expense included in the Company’s condensed consolidated statements of operations include (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease expense $ 261 $ 261 $ 782 $ 782 Variable lease expense 132 128 328 384 Total lease expense, net $ 393 $ 389 $ 1,110 $ 1,166
Summary of Weighted Average Remaining Lease Term and Weighted Average Discount Rate	The weighted average remaining lease term and weighted average discount rate for operating leases were as follows: As of September 30, 2022 2021 Weighted average remaining lease term (in years) 2.75 3.75 Weighted average discount rate percentage 3.50 % 3.50 %
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases under which the Company is the lessee was as follows (amounts in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cash paid for amounts included in the measurement of operating leases $ 401 $ 370 $ 1,155 $ 1,003
Maturities of Operating Lease Liabilities	As of September 30, 2022, future minimum payments under the Company's non-cancelable operating lease under ASC 842 were as follows (in thousands): Operating Three months ending December 31, 2022 $ 401 2023 1,636 2024 1,685 2025 845 Thereafter — Total future lease payments 4,567 Less: imputed interest ( 222 ) Total operating lease liabilities $ 4,345

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense for the three and nine months ended September 30, 2022 and 2021 has been reported in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended Nine Months Ended 2022 2021 2022 2021 Research and development $ 1,427 $ 1,267 $ 4,125 $ 3,376 General and administrative 2,161 3,099 6,937 17,931 Total $ 3,588 $ 4,366 $ 11,062 $ 21,307
Summary of Restricted Stock Units	The following table summarizes RSU activity under the 2020 Plan for the nine months ended September 30, 2022: Number of Weighted - Average Outstanding at December 31, 2021 975,046 $ 18.00 Granted — $ — Vested ( 335,305 ) $ 18.00 Forfeited ( 10,734 ) $ 18.00 Outstanding at September 30, 2022 629,007 $ 18.00
Summary of Stock Option Activity	The following table summarizes stock option activity under the 2020 Plan for the nine months ended September 30, 2022: Number of Weighted - Average Weighted -Average Aggregate Balance at December 31, 2021 1,086,902 $ 26.76 9.22 $ 991,495 Granted 1,667,200 $ 6.29 Exercised — $ — Forfeited ( 19,708 ) $ 26.95 Expired ( 15,464 ) $ 39.12 Balance at September 30, 2022 2,718,930 $ 14.00 9.06 $ 2,733,693 Vested and expected to vest at September 30, 2022 2,718,930 $ 14.00 9.06 $ 2,733,693 Exercisable at September 30, 2022 408,742 $ 26.18 8.34 $ —
Summary of Assumptions Used in Black-Scholes Model	The assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants were as follows: Nine Months Ended 2022 2021 Expected volatility 74.8 % 74.7 % Risk-free interest rate 2.09 % 0.99 % Expected dividend yield 0.0 % 0.0 % Expected term 6.04 5.86
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance are as follows in common equivalent shares: September 30, December 31, Warrants for the purchase of common stock — 151,088 Common stock options and restricted stock units issued and outstanding 3,347,937 2,061,948 Awards available for future issuance under the 2020 Plan 3,022,529 3,211,854 Awards available for future issuance under the ESPP 1,208,484 822,811 Total common stock reserved for future issuance 7,578,950 6,247,701

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Entity incorporation state country code	DE
Company formation date	2007-03
Accumulated deficit	$ 265,258	$ 186,319

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Schedule of Anti-dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	3,463,720	3,274,981
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	0	717,674
Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	2,718,930	960,402
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	629,007	1,592,796
ESPP Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	115,783	4,109

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule Of Prepaid Expenses Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Prepaid research and development	$ 3,978	$ 1,811
Prepaid insurance	692	0
Other prepaid expenses and current assets	519	502
Total	$ 5,189	$ 2,313

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 8,144	$ 7,933
Less accumulated depreciation and amortization	(5,142)	(4,257)
Total	3,002	3,676
Furniture Fixtures And Office Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 2,192	2,123
Furniture Fixtures And Office Equipment | Minimum
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	3 years
Furniture Fixtures And Office Equipment | Maximum
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	7 years
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	5 years
Property, plant and equipment, gross	$ 2,265	2,123
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 3,687	$ 3,687
Leasehold Improvements | Minimum
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	2 years
Leasehold Improvements | Maximum
Property Plant And Equipment [Line Items]
Property plant and equipment useful life	3 years

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accounts payable	$ 3,696	$ 1,179
Accrued compensation	2,979	2,671
Accrued research and development	14,713	13,501
Other accrued expenses	939	1,073
Total	$ 22,327	$ 18,424

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Assets measured at fair value	$ 0	$ 0
Liability measured at fair value	$ 0	$ 0

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Apr. 30, 2020
Debt Instrument [Line Items]
Debt description			The Company did not have any outstanding debt as of September 30, 2022 or December 31, 2021. In April 2020, the Company borrowed $0.7 million under the Paycheck Protection Program (“PPP”) under the CARES Act. The loan was subsequently forgiven in July 2021. The $0.7 million balance of the forgiven loan was recognized as other income on the Company's Statement of Operations for the three and nine months ended September 30, 2021. For the three and nine months ended September 30, 2021, the Company recognized interest expense related to its outstanding debt of $0 and $3,000, respectively.
Interest Expense				$ 3,000
Outstanding Debt [Member]
Debt Instrument [Line Items]
Interest Expense		0		3,000
Debt Instrument Outstanding Principal Amount	$ 0		$ 0		$ 0
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Debt Instrument Outstanding Principal Amount		$ 700,000		$ 700,000
PPP Loan
Debt Instrument [Line Items]
Debt Instrument Outstanding Principal Amount						$ 700,000

Leases (Additional Information)

Leases (Additional Information) (Details)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Lessor Operating Leases Option To Extend	5 years
Lessor, Operating Lease, Option to Extend	The lease expires in July 2025 and the Company has an option to extend the term of the lease for an additional five years. Additionally, the lease includes certain rent abatement, rent escalations, tenant improvement allowances and additional charges for common area maintenance and other costs.

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Leases [Abstract]
Operating lease expense	$ 261	$ 261	$ 782	$ 782
Variable lease expense	132	128	328	384
Lease, Cost, Total	$ 393	$ 389	$ 1,110	$ 1,166

Leases - Summary of Weighted Av

Leases - Summary of Weighted Average Remaining Lease Term And Weighted Average Discount Rate (Details)	Sep. 30, 2022	Sep. 30, 2021
Leases [Abstract]
Weighted average remaining lease term (in years)	2 years 9 months	3 years 9 months
Weighted average discount rate percentage	3.50%	3.50%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Leases [Abstract]
Cash paid for amounts included in the measurement of operating leases	$ 401	$ 370	$ 1,155	$ 1,003

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Leases [Abstract]
Three months ending December 31, 2022	$ 401
2023	1,636
2024	1,685
2025	845
Thereafter	0
Total future lease payments	4,567
Less: imputed interest	(222)
Total operating lease liabilities	$ 4,345

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Mar. 31, 2022
Class Of Stock [Line Items]
Beginning balances	$ 142,634		$ 142,634		$ 210,821
Proceeds from issuance of common stock				$ 75,001
Common stock, shares issued (in shares)	36,365,317		36,365,317		35,799,233
Stock-based compensation	$ 3,588	$ 4,366	$ 11,062	$ 21,307
Total fair value of options vested			$ 5,400
Total number of common shares reserved for issuance	7,578,950		7,578,950		6,247,701
Common Stock, Shares Authorized	350,000,000		350,000,000		350,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent			15%
Common Stock, Capital Shares Reserved for Future Issuance	7,578,950		7,578,950		6,247,701
Common stock authorized for issuance under plan	350,000,000		350,000,000		350,000,000
Warrants Expired And Unexercised					566,586
Equity Option
Class Of Stock [Line Items]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 16,400		$ 16,400
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			3 years 1 month 6 days
Share-based Payment Arrangement, Plan Modification, Number of Shares				7,747
Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value			$ 4.01
Restricted Stock Units (RSUs)
Class Of Stock [Line Items]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 11,300		$ 11,300
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			1 year 6 months
Share-based Payment Arrangement, Plan Modification, Number of Shares				138,461
2020 Equity Incentive Plan [Member]
Class Of Stock [Line Items]
Common shares authorized for issuance	7,658,509		7,658,509		6,226,540
Shares available for awards, description			On January 1st of each year, commencing with the first January 1st following the effective date of the 2020 Plan, the shares authorized for issuance under the 2020 Plan shall be increased by a number of shares equal to the lesser of 4% of the total number of shares outstanding on the immediately preceding December 31st and such lesser number of shares determined by the Company’s board of directors.
Vesting percentage			25%
Vesting period			36 months
Vesting terms, description			Awards under the 2020 Plan generally vest at 25% one year from the vesting commencement date and ratably each month thereafter for a period of 36 months, subject to continuous service.
Employees Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Total number of common shares reserved for issuance	1,208,484		1,208,484
Common Stock, Shares Authorized	1,229,148		1,229,148		833,993
Common Stock, Capital Shares Reserved for Future Issuance	1,208,484		1,208,484
Common stock authorized for issuance under plan	1,229,148		1,229,148		833,993
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Outstanding Stock Maximum			1%
Maximum annual increase of shares of common stock authorized for issuance			929,658
Common Stock
Class Of Stock [Line Items]
Issuance of common stock for Employee Stock Purchase Plan, shares			9,482	5,280
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares issued (in shares)	1,211,959		1,211,959		1,492,059
Common Stock, Shares Authorized	15,368,569		15,368,569		15,368,569
Common stock authorized for issuance under plan	15,368,569		15,368,569		15,368,569
IPO [Member] | Maximum
Class Of Stock [Line Items]
Warrants exercise period	450 days		450 days
IPO [Member] | Minimum
Class Of Stock [Line Items]
Warrants exercise period	365 days		365 days
IPO [Member] | Common stock warrants
Class Of Stock [Line Items]
Warrants expired (unexercised)						151,088
Remaining common stock warrants outstanding and exercisable	0		0
IPO [Member] | Common stock warrants | Maximum
Class Of Stock [Line Items]
Warrants exercise period						450 days
IPO [Member] | Common stock warrants | Minimum
Class Of Stock [Line Items]
Warrants exercise period					365 days

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Class Of Stock [Line Items]
Stock-based compensation	$ 3,588	$ 4,366	$ 11,062	$ 21,307
Research and Development Expense
Class Of Stock [Line Items]
Stock-based compensation	1,427	1,267	4,125	3,376
General and Administrative Expense
Class Of Stock [Line Items]
Stock-based compensation	$ 2,161	$ 3,099	$ 6,937	$ 17,931

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Restricted Stock Units (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Class Of Stock [Line Items]
Number of Outstanding Shares, Beginning Balance | shares	975,046
Number of Shares, Granted | shares	0
Number of Shares, Vested | shares	(335,305)
Number of Shares, Forfeited | shares	(10,734)
Number of Outstanding Shares, Ending Balance | shares	629,007
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 18
Weighted Average Grant Date Fair Value, Granted | $ / shares	0
Weighted Average Grant Date Fair Value, Vested | $ / shares	18
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	18
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 18

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity (Details) - Equity Option - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning Balance	1,086,902
Granted, Number of Shares	1,667,200
Forfeited, Number of Shares	(19,708)
Expired, Number of Shares	(15,464)
Number of Shares, Ending Balance	2,718,930	1,086,902
Vested and expected to vest, Number of Shares	2,718,930
Exercisable, Number of Shares	408,742
Outstanding, Beginning Balance, Weighted-Average Exercise Price per Share	$ 26.76
Granted, Weighted-Average Exercise Price per Share	6.29
Forfeited, Weighted-Average Exercise Price per Share	26.95
Exercised, Weighted-Average Exercise Price per Share	39.12
Outstanding, Ending Balance, Weighted-Average Exercise Price per Share | $ / shares	14	$ 26.76
Vested and expected to vest, Weighted-Average Exercise Price per Share	14
Exercisable Weighted-Average Exercise Price per Share	$ 26.18
Outstanding, Weighted-Average Remaining Contractual Term (years)	9 years 21 days	9 years 2 months 19 days
Vested and expected to vest, Weighted-Average Remaining Contractual Term (years)	9 years 21 days
Exercisable, Weighted-Average Remaining Contractual Term (years)	8 years 4 months 2 days
Outstanding, Aggregate Intrinsic Value	$ 2,733,693	$ 991,495
Vested and expected to vest, Aggregate Intrinsic Value	$ 2,733,693

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Assumptions Used in Black-Scholes Model (Details)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Expected volatility	74.80%	74.70%
Risk-free interest rate	2.09%	0.99%
Expected dividend yield	0%	0%
Expected term	6 years 14 days	5 years 10 months 9 days

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Common Stock, Shares, Issued	36,365,317	35,799,233
Common Stock, Shares, Outstanding	36,365,317	35,799,233
Total number of common shares reserved for issuance	7,578,950	6,247,701
Warrants [Member]
Class Of Stock [Line Items]
Warrants for the purchase of common stock	0	151,088
Common Stock Options and Restricted Stock Units [Member]
Class Of Stock [Line Items]
Common Stock, Shares, Issued	3,347,937	2,061,948
Common Stock, Shares, Outstanding	3,347,937	2,061,948
2020 Plan [Member]
Class Of Stock [Line Items]
Awards available for future issuance	3,022,529	3,211,854
Employees Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Awards available for future issuance	1,208,484	822,811
Total number of common shares reserved for issuance	1,208,484

Collaboration, License and Op_2

Collaboration, License and Option Agreements - Additional Information (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 18, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2019	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration Amendment Date				2019-12
Revenues		$ 0		$ 0	$ 300,000
Liability to licensor		19,806,000		$ 19,806,000			$ 19,806,000
BeiGene
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration Amendment Date				2020-10
Upfront Non-Refundable Payment						$ 25,000,000
Revenues		0	$ 0	$ 0	$ 0
Current portion of deferred revenue	$ 19,800,000	19,800,000		19,800,000			19,800,000
License termination information, Description	In the event the license is terminated, the liability will be extinguished with no further payment to BeiGene.
Liability to licensor		$ 19,800,000		$ 19,800,000			$ 19,800,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 23, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Related Party Transaction [Line Items]
Related party transaction, terms and manner of settlement					(i) a lump sum payment equal to 18 months of Ms. Anderson Short’s then-current base salary, (ii) a payment at her targeted bonus rate for 2021, pro-rated to the date of her termination of employment, and (iii) full accelerated vesting of her equity awards including 7,747 stock options and 138,461 restricted stock units. The modification of these equity awards resulted in an incremental fair value of $7.0 million which was recognized on a straight-line basis over the transition service period which ended on the separation date. For the three and nine months ended September 30, 2021, the Company recognized $0 and $1.0 million, respectively, related to the lump sum salary payment and target bonus. The Company also recognized non-cash stock-based compensation charges of $0 and $9.4 million related to the modified equity awards for the three and nine months ended September 30, 2021, respectively. No unrecognized stock-based compensation remained as of September 30, 2021.
Non-cash stock-based compensation charges		$ 3,588	$ 4,366	$ 11,062	$ 21,307
Research and development expense		19,839	16,553	$ 57,473	41,826
Himalaya Therapeutics SEZC
Related Party Transaction [Line Items]
Description of agreement with related party				In April 2022, the Company entered into a Clinical Trial Agreement with Himalaya Therapeutics SEZC. Under the agreement, Himalaya Therapeutics SEZC agreed to provide services related to the initiation of clinical trials for BA3011 in the People’s Republic of China. For the first year following effectiveness of the agreement, the Company has agreed to pay Himalaya Therapeutics SEZC for the full-time use of two of its personnel. Payments are due and payable by BioAtla to Himalaya Therapeutics SEZC on a quarterly calendar basis and are non-refundable. For the three and nine months ended September 30, 2022 the Company recognized $0.1 million in research and development expense related to the Clinical Trial Agreement. The Company did not have any amounts due from or due to Himalaya Therapeutics SEZC as of September 30, 2022.
Research and development expense		$ 100		$ 100
Carolyn Anderson Short
Related Party Transaction [Line Items]
Number of accelerated full vesting equity awards including stock options	7,747
Number of accelerated full vesting equity awards including restricted stock units	138,461
Incremental Fair Value					7,000
Expense related to Lump Sum Salary Payment and Target Bonus			0		1,000
Non-cash stock-based compensation charges			0		9,400
Unrecognized stock-based compensation			$ 0		$ 0

401(k) Plan - Additional Inform

401(k) Plan - Additional Information (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Contributions made by Company	$ 0	$ 0