BioAtla : BCAB_Corp_Update_May 2024_FINALv3

Conditionally Active

Biologics: Transforming

Cancer Therapy

Corporate Presentation

May 2024

Important Notices & Disclaimers

This presentation (the "Presentation") by BioAtla, Inc. ("we", "us", "our", "BioAtla", or the "Company") contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 relating to our business, operations and financial conditions, including but not limited to statements regarding business plans and prospects and whether our clinical trials will support registration; achievement of milestones; results, conduct, progress and timing of our research and development programs and clinical trials; expectations with respect to enrollment and dosing in our clinical trials, plans and expectations regarding future data updates, clinical trials, regulatory meetings and regulatory submissions; plans to form collaborations or other strategic partnerships for selected assets; the potential regulatory approval path for our product candidates; expectations about the sufficiency of our cash and cash equivalents to fund operations. Words such as, but not limited to, "anticipate", "believe", "could", "estimate", "expect", "intend", "may", "plan", "potential", "predict", "project", "should", "will", "would" or the negative of those terms, and similar expressions that convey uncertainty of future events or outcomes, identify forward-looking statements.

These forward-looking statements reflect management's beliefs and views with respect to future events and are based on estimates and assumptions as of the date of this Presentation and are subject to risks and uncertainties, including those described in the Company's filings with the SEC, including but not limited to the Company's latest Annual Report on Form 10-K and any subsequently filed Quarterly Reports on Form 10-Q. Moreover, the Company operates in a very competitive and rapidly changing environment. New risks emerge from time to time. It is not possible for management to predict all risks, nor can the Company assess the impact of all factors on its business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. Given these uncertainties, you should not place undue reliance on these forward-looking statements. The Company qualifies all the forward-looking statements in this Presentation by these cautionary statements. Except as required by law, the Company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.

Statements contained herein are made as of the date of this Presentation unless stated otherwise, and this Presentation shall not under any circumstances create an implication that the information contained herein is correct as of any time after such date or that the information will be updated or revisited to reflect information that subsequently becomes available or changes occurring after that date hereof.

Certain information contained in this Presentation relates to or is based on statistical and other industry and market data obtained from independent industry publications and research, surveys and studies conducted by independent third parties as well as the Company's own estimates of the prevalence of certain diseases and conditions. The market data used in this Presentation involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such data. Industry publications and third-party research, surveys and studies generally indicate that their information has been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. The Company's estimates of the patient population with the potential to benefit from treatment with any product candidates the Company may develop include several key assumptions based on its industry knowledge, industry publications and third-party research, which may be based on a small sample size and may fail to accurately reflect the addressable patient population. While the Company believes that its internal assumptions are reasonable, no independent source has verified such assumptions.

This Presentation may contain trademarks, trade names, or service marks belonging to other entities. The Company does not intend the use or display of other parties' trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of, or by these other parties.

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BioAtla | Overview 2

Bioatla© Is A Clinical Stage Company Focused On Transforming Cancer Therapy

with Conditionally Active Biologics (CABs)

	Two Phase 2 CAB-ADCs, one
Proprietary technology	Phase 2 CAB-CTLA-4 and one
Phase 1 dual CAB-bispecific T-
Broad applicability in solid	cell engager
tumors	Mecbotamab vedotin
Increases therapeutic	advancing potentially
window	registrational trial in
	Undifferentiated Pleomorphic
	Sarcoma (UPS)

Clinical readouts for multiple indications / assets through 2024

Advancing strategic

collaboration discussions

$80.6 million in cash and cash

equivalents as of 03/31/24

Cash position sufficient into

2H 2025

BioAtla | Overview 3

Leadership Team

Jay Short, Ph.D.	Richard Waldron, M.B.A.	Eric Sievers, M.D.	Sheri Lydick
Chairman, CEO and Cofounder	Chief Financial Officer	Chief Medical Officer	Chief Commercial Officer
	GeneMedicine, Inc.

Bin Zhang, M.D.	William Boyle, Ph.D.	Monica Sullivan	Susie Melody
Sr. VP, Clinical Development.	Sr. Research Fellow	Sr. VP, Intellectual Property & Contracts	Sr. VP, Human Resources
		CapaIP

BioAtla | Overview 4

Board of Directors and Scientific Advisors

Jay Short, Ph.D.
Chairman, Chief Executive	Mary Ann Gray, Ph.D.	Sylvia McBrinn	Susan Moran, MD, MSCE
Officer & Cofounder	Director	Director	Director
Director

Scott Smith	Lawrence Steinman, MD	Eddie Williams
Director	Director	Director

James Allison, Ph.D.	Lawrence Fong, MD
Cancer Immunotherapy
MD Anderson Cancer Center
Program, UCSF
Scientific Advisor
Scientific Advisor

Padmanee Sharma, MD, Ph.D.	Michael Manyak, MD
MD Anderson Cancer Center	GlaxoSmithKline
Scientific Advisor	Scientific Advisor

BioAtla | Overview 5

Selective And Targeted CAB Technology Widens Therapeutic Window

Thus has the potential to enhance clinical outcomes in multiple tumor types

BioAtla discovered that acidic pH at the cancer cell surface unveils binding sites that are shielded at normal pH of healthy cells

BioAtla invented CAB technology, creating antibodies that bind only to these unveiled sites on cancer cells

CAB binding region is not masked or caged and thus different from prodrugs that require irreversible enzymatic cleavage to become activated

CAB antibodies have the potential for increased efficacy with improved safety relative to traditional antibodies

Alkaline Healthy Cell Membrane		Acidic Cancer Cell Membrane

No CAB Binding	CAB Binding
H+
	H+ H+
	H+
H+	H+
H+	H+
H+
	H+

Chang, H.W., Frey, G., Liu, H., Xing, C., Steinman, L, Boyle, B.J., & Short, J.M. (2021) PNAS 118(9): 1-10, Suppl. 1-19.

BioAtla | Overview 6

Broad Applicability Of BioAtla's CAB Platform Across Several Antibody Types

I/O Antibodies	ADCs
Target: CTLA-4	Targets: ROR2, AXL
CTLA-4 blockade activates effector	Widely expressed in a variety of tumor
T cells, thereby enhancing anti-	types, ROR2 and AXL overexpression
tumor immunity	correlates with poor prognosis,

				metastasis, and drug resistance to PD-1
				and EGFR therapies
CAB-CTLA4				CAB-CTLA4
				CAB-Tumor Cell Target
								Cytotoxic payload
								and linker

Bispecific TCE

Target: EpCAM & CD3

Bispecific antibodies bridge cancer cells and cytotoxic T lymphocytes, activating T cells and promoting cancer cell lysis

Tumor Cell Target

CAB-EpCAM

T Cell Target

CAB-CD3

ADC - antibody drug conjugate; IO - immuno-oncology; TCE - T-cell engager

BioAtla | Overview 7

Focused Pipeline with Broad Applicability of Differentiated CAB Assets Designed to Deliver Near-term value

CAB Program

Target

Indications

IND Enabling Pre-Clinical

Phase 1 Clinical

Phase 2 Clinical

	Mecbotamab Vedotin	AXL	UPS
	NSCLC
CAB-ADCs
Ozuriftamab Vedotin	ROR2	Melanoma
	SCCHN
			Melanoma
CAB-I/O	Evalstotug	CTLA-4	NSCLC
			Carcinomas
CAB-	BA3182	EpCAM x CD3	Adenocarcinomas
Bispecific TCE
Next Gen	BA3361	Nectin-4	Multiple tumor types
CAB-ADC

IND, investigational new drug; UPS, Undifferentiated Pleomorphic Sarcoma; NSCLC, Non-small Cell Lung Cancer; SCCHN, Squamous Cell Carcinoma of the Head and Neck	BioAtla | Overview 8

Evalstotug (CAB-CTLA-4): Basket Trial

CAB-CTLA4 Selectively Active in Tumor Microenvironment, Thereby Reducing Immune Related Adverse Events (irAEs)

	Severe irAEs	Minimized irAEs
Non-CABCTLA-4						Normal Cell (alkaline)		CAB CTLA-4
inhibitors							Tumor selective binding
anti-CTLA4					anti-CTLA4	CAB-anti-CTLA4		CAB-anti-CTLA4
						Cancer cell (acidic)

Cytotoxic (CD8+) T cells

T regulatory cells

Normal Cell

Normal Cell

BioAtla | Overview 10