BriaCell Therapeutics Corp.: BriaCell Phase 2 Survival Achievement: 52% of Patients Surpass One-Year Milestone in Metastatic Breast Cancer

• 52% of BriaCell's most-recent 25-patient cohort* have surpassed the one-year survival milestone, exceeding current standard of care in similar patients
• 11 patients remain alive as of recent contact, including one patient at 38.3 months and another at 30.3 months
• Survival benefit observed in heavily pre-treated patients, including those who failed treatment with checkpoint inhibitors (CPIs) and antibody-drug conjugates (ADCs)

PHILADELPHIA and VANCOUVER, British Columbia, July 08, 2025 (GLOBE NEWSWIRE) -- BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXW, BCTXZ) (TSX: BCT) ("BriaCell" or the "Company"), a clinical-stage biotechnology company developing novel immunotherapies to transform cancer care, has reported updated survival data from its ongoing Phase 2 clinical study of Bria-IMT in patients with metastatic breast cancer (MBC).

• BriaCell's most recent Phase 2 study cohort of 25 patients* achieved a 52% one-year survival rate (i.e. 52% of patients remained alive at least one year after starting on the study).
• 11 of these patients remain alive as of most recent contact, including one patient at 38.3 months and another at 30.3 months (see Table 1).
• Survival rate exceeds the survival expectations with the current standard of care therapies in similar patient populations (see Table 2).
• Notably, many patients had very advanced metastatic breast cancer, having already failed multiple prior lines of therapy including check point inhibitors (CPIs) and antibody-drug conjugates (ADCs) such as TRODELVY® - (sacituzumab govitecan-hziy) and ENHERTU® (fam-trastuzumab - deruxtecan-nxki).
• No treatment discontinuations attributed to Bria-IMT have been reported.

Table 1: Select Long-Term Responders
Patient	Months Survival	Age	Prior Regimens	Cycles of Bria-IMT
01-009	38.3	74	5	13
07-001	30.3	55	7; including ENHERTU	8
11-018	21.6	66	8	28
11-019	20.0	63	9; including TRODELVY	6
16-003	19.4	80	5; including ENHERTU	8

"BriaCell's Phase 2 data indicate a robust survival signal and a well-tolerated profile," 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. "These results reinforce BriaCell's potential to improve survival and tolerability for late-stage patients."

"Many patients with metastatic breast cancer unfortunately have disease progression despite treatment with CPIs and ADCs," added Aditya Bardia, MD, MPH, FASCO, a leading breast cancer expert. "BriaCell's survival data in single arm Phase 2 trial highlights the potential activity of Bria-IMT in combination with CPIs and is subject to ongoing investigation in a Phase 3 randomized clinical trial in MBC."

Table 2: Comparable Analysis of One-Year Survival
Reference	Breast Cancer Type	Median prior lines of therapy	Percent Survival at 1 year
Bria-IMT plus CPI	All types: 61% HR+ 33% TNBC 6% HER2+	6	52%*
Cortes et al.1	All types: 57% HR+ 18-19% TNBC 18-20% HER2+	4	~38-40%
Kazmi et al.2	All types: 51-52% HR+ 25-29% TNBC 9-24% HER2+	2	30-38%
Bardia et al. (TPC arm)3	TNBC	2-3	~23%
Rugo et al (TPC arm)4	HR+ HER2-	2	47%
* 25 patients treated with the Phase 3 formulation since 2022 Cortes J, et al. Annals of Oncology 2018 Kazmi S, et al. Breast Cancer Res Treat. 2020 Bardia A, et al. J Clin Oncol. 2024 Rugo HS, et al. The Lancet. 2023

Abbreviations:

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

BriaCell's 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 for some sub populations 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: BriaCell's potential to improve survival and tolerability for late-stage metastatic breast cancer patients; the impact of Bria-IMT on patients with metastatic breast cancer; and BriaCell's further clinical development of Bria-IMT 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.

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Contact Information

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