BCTX BriaCell Therapeutics Corporation

BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXW) (TSX: BCT) (“BriaCell” or the “Company”), a clinical-stage biotechnology company that develops novel immunotherapies to transform cancer care, announces new positive survival data, outperforming patients, and survival rates in its Phase 2 metastatic breast cancer (MBC) study.

In BriaCell’s Phase 2 clinical study, patients treated with the same Bria-IMT™ regimen formulation being used in the ongoing Phase 3 pivotal trial experienced a one-year survival rate of 55% (i.e. 55% of patients remain alive at least one year after starting on the study). This rate exceeds the survival data of the current standard of care for similar patients (see Table 1). Notably, 4 of 13 patients recruited in 2022 remain in survival follow-up as well, including:

• Patient 01-009: Overall survival (OS) of 25 months has been reported in a patient who had failed 6 prior treatments prior to the BriaCell regimen. Stable disease and lymph node shrinkage has been recorded during 13 cycles of therapy.
• Patient 07-001: OS of 24 months. She had stable disease and received 8 cycles of BriaCell’s therapy.
• Patient 16-003: OS of 15 months and received 8 cycles of therapy with stable disease. Prior to the BriaCell regimen, she had 7 lines of therapy, which included the progression of disease while on the antibody-drug conjugate (ADC) Enhertu.
• Patient 11-018: OS of 14 months. This previously-reported responder with 100% resolution of her brain metastasis has recently completed her 19th cycle of therapy.

“With over 40,000 deaths each year in the US alone, late-stage MBC remains an important unmet medical need for many patients and their families. Approved treatments are restricted by poor survival and harsh side effects,” stated Adam M. Brufsky, MD, PhD, FACP, Professor of Medicine at the University of Pittsburgh School of Medicine and Medical Director of the Magee-Women's Cancer Program. “We are impressed with BriaCell’s promising randomized Phase 2 survival data indicating robust survival and a preferred tolerability profile for Bria-IMT™ and look forward to seeing the data being replicated in BriaCell’s pivotal Phase 3 study.”

“A number of patients with metastatic breast cancer have disease progression on currently approved drugs, including CPIs and ADCs, with limited overall survival,” remarked Dr. Aditya Bardia, Program Director of Breast Medical Oncology at UCLA, who was not involved with the BriaCell Phase 2 clinical trial. “BriaCell’s clinical data is interesting and highlights the role of the combination of Bria-IMT™ with CPIs in MBC.”

“Significant numbers of patients with metastatic breast cancer do not respond to currently approved drugs, including CPIs and ADCs, and have a very limited lifespan of weeks to a few months,” said Dr. William V. Williams, BriaCell’s President and CEO. “BriaCell’s clinical data supports our hypothesis that our regimen has prolonged survival in patients with metastatic breast cancer who otherwise have not responded to currently available treatments. We look forward to further confirming these impressive data in our ongoing pivotal Phase 3 study, with interim results expected in the second half of 2025. Overall survival is the primary endpoint in our pivotal Phase 3 study.”

Table 1: Comparable Analysis of 1 year survival for the BriaCell Phase 2 study
Reference	Breast Cancer Type	Median prior lines of therapy	Median OS (months)	Percent Survival at 1 year
Bria-IMT™ plus CPI	All types61% HR+33% TNBC6% HER2+	6	13.4* 15.6**	55%
Cortes et al.1	All types 57% HR+ 18-19% TNBC18-20% HER2+	4	9.1-9.3	~38-40%
Kazmi et al.2	All types 51-52% HR+ 25-29% TNBC9-24% HER2+	2	7.2-9.8	30-38%
Bardia et al. (TPC arm)3	TNBC	2-3	6.9	~23%
Rugo et al (TPC arm)4	HR+ HER2-	2	11.2	47%
* Patients treated with the Phase 3 formulation
** Patients treated with the Phase 3 formulation since 2022
1. Cortes J, et al. Annals of Oncology 2018
2. Kazmi S, et al. Breast Cancer Res Treat. 2020
3. Bardia A, et al. J Clin Oncol. 2024
4. Rugo HS, et al. The Lancet. 2023

Abbreviations: HR+: hormone receptor-positiveTNBC: Triple-negative breast cancer (lacks or has low levels of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2))HER2+: Human epidermal growth factor receptor 2 positiveHR+ HER2-: hormone receptor-positive and human epidermal growth factor receptor 2 negativeTPC: Treatment of Physicians Choice

The Phase 2 study enrolled 54 heavily pre-treated metastatic breast cancer patients (median number of prior treatments = 6) who received the Bria-IMT™ regimen plus checkpoint inhibitor. Of these 54 patients, 37 were treated with the formulation currently being used in BriaCell’s ongoing pivotal Phase 3 study in metastatic breast cancer (listed on ClinicalTrials.gov as NCT06072612). Final median overall survival calculation for the Phase 2 study is pending, as many patients remain alive. No Bria-IMT™ related discontinuations have been reported to date.

About BriaCell Therapeutics Corp.

BriaCell is a clinical-stage biotechnology company that develops novel immunotherapies to transform cancer care. More information is available at https://briacell.com/.

Safe Harbor

This press release contains “forward-looking statements” that are subject to substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this press release are forward-looking statements. Forward-looking statements contained in this press release may be identified by the use of words such as “anticipate,” “believe,” “contemplate,” “could,” “estimate,” “expect,” “intend,” “seek,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “target,” “aim,” “should,” “will,” “would,” or the negative of these words or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements, including statements about: the impact of Bria-IMT™ on patients with metastatic breast cancer; BriaCell’s further clinical development of Bria-IMT™; the Company’s beliefs regarding the results of BriaCell’s pivotal Phase 3 study; and the efficacy of immune check point inhibitors, are based on BriaCell’s current expectations and are subject to inherent uncertainties, risks, and assumptions that are difficult to predict. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate. These and other risks and uncertainties are described more fully under the heading “Risks and Uncertainties” in the Company’s most recent Management’s Discussion and Analysis, under the heading “Risk Factors” in the Company’s most recent Annual Information Form, and under “Risks and Uncertainties” in the Company’s other filings with the Canadian securities regulatory authorities and the U.S. Securities and Exchange Commission, all of which are available under the Company’s profiles on SEDAR+ at www.sedarplus.ca and on EDGAR at www.sec.gov. Forward-looking statements contained in this announcement are made as of this date, and BriaCell Therapeutics Corp. undertakes no duty to update such information except as required under applicable law.

Neither the Toronto Stock Exchange nor its Regulation Services Provider (as that term is defined in the policies of the Toronto Stock Exchange) accepts responsibility for the adequacy or accuracy of this release.Contact Information

Company Contact: William V. Williams, MDPresident & CEO 1-888-485-6340 info@briacell.com 

Media Relations: Jules Abraham CORE IR julesa@coreir.com

Investor Relations Contact: CORE IR investors@briacell.com

1 Patients treated with the Bria-IMT™ formulation being used in the phase 3 study.