BioAtla : JPM fireside chat

Conditionally Active

Biologics: Transforming

Cancer Therapy

JPM Conference 2023

Fireside Chat

January 10, 2023

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 current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, results of clinical trials and other future conditions. 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 Quarterly Report 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.

None of the Company or any of its directors, officers, employees, contractors, agents, consultants, advisors or other representatives makes any representation or warranty, express or implied, as to the accuracy or completeness of the information contained in this Presentation.

BioAtla | Overview 2

BioAtla© is a clinical stage company focused on transforming cancer therapy

with Conditionally Active Biologics (CABs)

Proprietary technology	Two Phase 2 CAB-ADCs	Diversified pipeline	Strong cash position
and one Phase 1
(>700 patents)
CAB-CTLA-4	Near-term clinical	$178.1MM (3Q22) + $65MM
Broad applicability in solid	Interim BA3011 Phase 2	readouts for multiple	(RD 11/12) with runway into
tumors	indications	1H 2025
data supports advancing
Increases therapeutic	to registration studies in	Strategic optionality	Sufficient through key
multiple sarcoma and
window		clinical milestones
NSCLC indications

BioAtla | Overview 3

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 4

Broad applicability of BioAtla's CAB platform across several antibody types

has the potential to treat multiple solid tumors

ADCs

Naked Antibodies I/O

Bispecific TCE

Targets: AXL, ROR2

Target: CTLA-4

Target:

EpCAM & CD3

Widely expressed in a variety of tumor

CTLA-4 blockade activates effector

Bispecific antibodies bridge cancer

types, AXL and ROR2 overexpression

T cells, thereby enhancing anti-

cells and cytotoxic T lymphocytes,

correlates with poor prognosis,

tumor immunity

activating T cells and promoting

metastasis, and drug resistance to PD-1

cancer cell lysis

and EGFR therapies

CAB-CTLA4

CAB-CTLA4

CAB-Tumor Cell Target

Tumor Cell Target

CAB-EpCAM

Cytotoxic payload

T Cell Target

CAB-CD3

and linker

Nextgen: CAB-ADCmaxTM;CAB-Butterfly BispecificTM	BioAtla | Overview 5
ADC - antibody drug conjugate; I/O - immuno-oncology; TCE - T-cell engager