BriaCell Completes Manufacturing of Clinical Supplies of Bria-PROS+™ for Prostate Cancer

• Bria-PROS+ is BriaCell’s next generation personalized off-the-shelf immunotherapy for prostate cancer

• Immune stimulating components of Bria-PROS+ enhance anti-tumor responses

• BriaCell has completed manufacturing clinical supplies of Bria-PROS+ and plans to initiate a Phase 1/2a clinical study in prostate cancer in the coming months

PHILADELPHIA and VANCOUVER, British Columbia, May 14, 2026 (GLOBE NEWSWIRE) -- BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXL) (TSX: BCT) (“BriaCell” or the “Company”), a clinical-stage biotechnology company developing novel immunotherapies to transform cancer care, announces that it has completed manufacturing clinical supplies of Bria-PROS+, its next generation, personalized, off-the-shelf, cell-based immunotherapy candidate for prostate cancer.

In August 2025,BriaCell was awarded a $2 million non-dilutive grantfrom the US National Cancer Institute to support the manufacturing and planned clinical evaluation of Bria-PROS+.

“We are pleased to announce the completion of clinical supply manufacturing for Bria-PROS+, our next generation personalized immunotherapy candidate for prostate cancer,” stated Dr. William V. Williams, BriaCell’s President & CEO. “The design of Bria-PROS+ is intended to support enhanced immune system activation while maintaining a favorable safety profile. We look forward to advancing Bria-PROS+ into the clinic as we seek to develop new treatment options for prostate cancer patients who do not respond to available therapies.”

Asreported in BriaCell’s recent AACR preclinical poster presentation, Bria-PROS+ demonstrated activation of both adaptive and innate immunity including activation of naïve (resting) T-cells, dendritic cells and natural killer (NK) cells. BriaCell believes these preclinical findings support further clinical evaluation as a potential immunotherapy for prostate cancer. Bria-PROS+ is based on the same Bria-OTS+ platform as Bria-BRES+, BriaCell’s next generation breast cancer immunotherapy candidate, whichrecently received FDA clearance of its Investigational New Drug (IND) application.

Bria-PROS+ builds on Bria-Cell’s Bria-OTS clinical program in breast cancer, where the first patient dosed experienced thesustained complete resolution of a lung metastasis. This 78-year-old woman with advanced metastatic breast cancer and multiple prior treatment failures achieved complete (100%) resolution of a lung metastasis following four doses of Bria-OTS single agent therapy. The complete response of the lesion, initially observed at 2 months, was subsequently confirmed at 4 months, 6 months, and at 11 months. The patient received 17 cycles of Bria-OTS, completed 12 months of the study, and remains in survival follow-up.

BriaCell is an immuno-oncology-focused biotechnology company developing targeted and effective approaches for the management of cancer. More information is available athttps://briacell.com/.

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 those about the completion of clinical supply manufacturing for Bria‑PROS+, the planned initiation of a Phase 1/2a clinical study, and expectations regarding the potential clinical benefits of the Bria‑OTS+ platform, 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+ atwww.sedarplus.caand on EDGAR atwww.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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