BriaCell and BriaPro to Present Preclinical Anti-Cancer Activity and Immunotherapy Findings at SITC 2026 

The findings span laboratory tumor-cell killing, monkey tolerability data and engineered proteins with altered immune-receptor binding.

Rhea-AI Summary

BriaCell Therapeutics (Nasdaq: BCTX) and majority-owned BriaPro will present four preclinical studies at SITC, taking place November 4–8, 2026.

Bria-OTS+ activated immune cells and produced tumor-cell killing in laboratory breast, prostate and lung cancer models, including immune activation in cells obtained from cancer patients. BriaPro’s BP-80 showed a no observed effect level of 50 mg/kg/day in cynomolgus monkeys, with a half-life of 8.08–8.92 hours. In a cell-based study, TILsRx-001 counteracted PD-L1-mediated immune inhibition on cells also expressing B7-H3. An engineered CD80 variant showed more than 130-fold stronger PD-L1 binding than wild-type CD80; another mutation increased CTLA-4 affinity approximately fivefold while preserving CD28 affinity. BriaCell said it is advancing clinical evaluation of Bria-OTS+ while continuing preclinical development of BriaPro’s candidates.

Positive

• Minor pointBria-OTS+ activated immune cells and induced sustained tumor-cell killing in laboratory breast, prostate and lung cancer models.
• Minor pointBria-OTS+ also induced immune activation in cells obtained from cancer patients.
• Minor pointBP-80 demonstrated CD28 co-stimulatory activity and counteracted CTLA-4-mediated inhibition in cell-based assays.
• Minor pointBP-80 showed a no observed effect level of 50 mg/kg/day in cynomolgus monkeys.
• Minor pointTILsRx-001 counteracted PD-L1-mediated immune inhibition in a cell-based study involving cells also expressing B7-H3.

3 minor points

• Minor pointCD80 variant showed more than 130-fold stronger PD-L1 binding than wild-type CD80, with minimal effect on CD28 affinity.
• Minor pointAnother CD80 mutation increased CTLA-4 affinity approximately fivefold while preserving CD28 affinity.
• Minor pointBriaCell is advancing Bria-OTS+ clinical evaluation while continuing BriaPro candidates’ preclinical development.

Negative

• Minor pointBP-80 assay activity depended on Fc receptor engagement for CD28 co-stimulation and antibody-based crosslinking for counteracting CTLA-4 inhibition.

News Explained

The release adds cell-assay findings for BriaPro’s BP-80: it showed CD28 co-stimulatory activity and counteracted CTLA-4-mediated inhibition, with those activities dependent, respectively, on Fc-receptor engagement and anti-Fc-antibody crosslinking.

Key Figures

NOEL: 50 mg/kg/day Half-life: 8.08–8.92 hours PD-L1 binding affinity: More than 130-fold stronger (0.23 µM versus >30 µM) +1 more

NOEL

50 mg/kg/day

BP-80 in cynomolgus monkeys

Half-life

8.08–8.92 hours

BP-80 in cynomolgus monkeys

PD-L1 binding affinity

More than 130-fold stronger (0.23 µM versus >30 µM)

Engineered CD80 variant versus wild-type CD80

CTLA-4 affinity

Approximately fivefold increase

Another CD80 mutation; CD28 affinity preserved

Key Terms

no observed effect level (noel), single-chain variable fragment (scfv), tumor-infiltrating lymphocyte (til), allogeneic

4 terms

no observed effect level (noel) technical

"a no observed effect level (NOEL) of 50 mg/kg/day"

No observed effect level (NOEL) is the highest tested exposure or dose of a substance in a study at which no treatment-related adverse or measurable biological effects are detected compared with a control group. It is determined through controlled laboratory or clinical studies that measure specific endpoints (for example, clinical signs, blood chemistry, organ weight, or other biomarkers) and may differ depending on which effect is being measured; when studies do detect a lowest dose with any effect, that dose is reported as the lowest observed effect level (LOEL). NOEL is an experimental point used by regulators and risk assessors as part of safety evaluations, but it depends on the study design, the endpoints chosen, and the sensitivity of measurements, so it is not an absolute safe threshold across all contexts.

single-chain variable fragment (scfv) medical

"an anti-B7-H3 single-chain variable fragment (scFv) for tumor targeting"

A single-chain variable fragment (scFv) is a small, engineered piece of an antibody that contains the part that recognizes and binds a specific target, like a lock-and-key tip separated from the rest of the antibody. Investors should care because scFvs are often used as the active component in targeted therapies, diagnostic tests, and drug delivery tools; their small size and manufacturability can affect treatment effectiveness, production cost, regulatory approval, and commercial potential.

tumor-infiltrating lymphocyte (til) medical

"tumor-infiltrating lymphocyte (TIL) activity"

Tumor-infiltrating lymphocytes (TILs) are white blood cells that have moved into a tumor and are recognizing cancer cells as a threat. They matter to investors because therapies that collect a patient’s TILs, grow them in the lab and return them aim to boost the body’s own attack on cancer; successful results can create a new treatment market and trigger regulatory and commercial milestones. Think of TIL therapy as strengthening a local neighborhood watch to remove intruders.

allogeneic medical

"a modular allogeneic whole-cell vaccine platform"

Allogeneic describes a process or material involving different individuals of the same species, such as cells, tissues, or organs donated from one person to another. It is important to investors because products or treatments based on allogeneic sources can enable scalable, off-the-shelf solutions, potentially reducing costs and increasing accessibility in healthcare and biotech industries.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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• Four presentations highlight BriaCell’s Bria-OTS+™ cellular immunotherapy platform and BriaPro’s CD80-based immunotherapy programs
• In vitro Bria-OTS+ studies demonstrate immune-cell activation and tumor-cell killing across breast, prostate and lung cancer models
• BriaPro data describes BP-80 tolerability in nonhuman primates and engineered CD80 constructs with enhanced PD-L1 binding
  
  

PHILADELPHIA and VANCOUVER, British Columbia, Nov. 03, 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, and its majority-owned subsidiary, BriaPro Therapeutics Corp. (“BriaPro”), today announced four preclinical research presentations at the Society for Immunotherapy of Cancer (SITC) 41^th Anniversary Annual Meeting, taking place November 4-8, 2026, in Phoenix, AZ.

The presentations cover BriaCell’s personalized off-the-shelf immunotherapy platform, Bria-OTS+, and three BriaPro research programs: BP-80, a soluble CD80-Fc fusion protein; TILsRx-001, a tumor-targeted CD80-based checkpoint inhibitor; and engineered CD80 variants with altered immune receptor binding.

“The Bria-OTS+ studies demonstrate immune-cell activation and tumor-cell killing in laboratory models spanning breast, prostate and lung cancers,” said Miguel A. Lopez-Lago, PhD, BriaCell’s Chief Scientific Officer. “These findings support continued investigation of the platform, including how its immune responses may translate into clinical activity, potentially providing more durable and effective cancer immunotherapies.”

“The four presentations provide additional preclinical data supporting our cellular and protein-based immunotherapy research,” stated William V. Williams, MD, BriaCell’s President and CEO. “We are advancing the clinical evaluation of our Bria-OTS+ programs while continuing preclinical development of BriaPro’s candidates.”

Presentation abstract summaries are listed below.

BriaCell

Title: A Multifaceted Genetically Engineered Whole-Cell Vaccine Platform Generates Potent, Broad, Persistent, and Effector-Centric Anti-Tumor Immunity Across Multiple Cancer Indications
Abstract Number: 863
Location: PCC-North Building-Lower Level-Exhibition Halls 4-5-6
Date: Friday, Nov. 6, 2026

Summary: Bria-OTS+ is a modular allogeneic whole-cell vaccine platform engineered to combine tumor-derived antigens, immune-stimulatory cytokines, co-stimulatory molecules, and diverse HLA antigens. Bria-OTS+ activated innate and adaptive immune cells, including dendritic, NK, NKT, CD4+ T, and CD8+ T cells, represented by increased activation markers, cytokine production, proliferation, and cytotoxicity. Bria-OTS+ also induced immune activation in PBMCs obtained from cancer patients, extending these findings beyond healthy-donor models.

In vitro studies showed that Bria-OTS+ stimulated innate and adaptive immune responses, broad tumor recognition, sustained cytotoxicity, and memory-like responses across breast, prostate, and lung cancer models, supporting its potential as a broadly applicable cancer immunotherapy platform.

BriaPro

Title: Development of BP-80, a soluble CD80 dimer (CD80-Fc) for cancer treatment
Abstract Number: 404
Location: PCC-North Building-Lower Level-Exhibition Halls 4-5-6
Date: Saturday, Nov. 7, 2026

Summary: BP-80 is a soluble CD80-Fc fusion protein incorporating the full wild-type CD80 extracellular domain, designed to promote T cell activation through CD28 co-stimulation and counteracting CTLA-4-mediated inhibition. Its Fc region contains L234A/L235A (LALA) mutations to reduce antibody-dependent effector functions. In cell-based assays, BP-80 demonstrated CD28 co-stimulatory activity and counteracted CTLA-4-mediated inhibition, with activity dependent on Fc receptor engagement and anti-Fc antibody-based crosslinking, respectively. In cynomolgus monkeys, BP-80 demonstrated a no observed effect level (NOEL) of 50 mg/kg/day and a half-life ranging from 8.08 to 8.92 hours.

Title: Tumor-targeted checkpoint inhibitors for reactivation of tumor-infiltrating lymphocytes
Abstract Number: 405
Location: PCC-North Building-Lower Level-Exhibition Halls 4-5-6
Date: Friday, Nov. 6, 2026

Summary: TILsRx-001 is a tumor-targeted, tetravalent immune checkpoint inhibitor comprising an engineered CD80 extracellular domain with enhanced PD-L1 affinity and an anti-B7-H3 single-chain variable fragment (scFv) for tumor targeting. In a cell-based study, TILsRx-001 antagonized the immune inhibitory effect of PD-L1 expressed on cells co-expressing B7-H3, supporting further investigation of targeted checkpoint inhibition to enhance tumor-infiltrating lymphocyte (TIL) activity.

Title: Molecular design of CD80 variants with increased affinity for PD-L1 and wild-type or lower affinity for CD28
Abstract Number: 406
Location: PCC-North Building-Lower Level-Exhibition Halls 4-5-6
Date: Saturday, Nov. 7, 2026

Summary: CD80 (B7-1) regulates T cell activity through interactions with CD28, PD-L1, and CTLA-4. Structure-guided protein engineering identified CD80 variants with increased PD-L1 binding affinity and minimal effect on CD28 affinity, a potential approach to limiting excessive T cell stimulation. One variant demonstrated more than 130-fold stronger PD-L1 binding than wild-type CD80 (0.23 µM versus >30 µM). Another mutation increased CTLA-4 affinity approximately fivefold while preserving CD28 affinity. These findings support further development of engineered CD80 proteins for cancer immunotherapy.

About BriaCell Therapeutics Corp.

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

About BriaPro Therapeutics Corp.

BriaPro is a pre-clinical stage immunotherapy company developing binding agents and proteins with the intention to boost the ability of the body’s own cancer-fighting cells to destroy cancerous tumors.

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 those about BriaCell and BriaPro presenting posters at the SITC 2026 Annual Meeting, and the contents of such posters, 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, MD
President & CEO
1-888-485-6340
info@briacell.com 

Investor Relations Contact:
investors@briacell.com

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did BriaCell’s Bria-OTS+ preclinical studies show at SITC 2026?

Bria-OTS+ activated immune cells and produced tumor-cell killing in laboratory models of breast, prostate and lung cancer. The studies also showed sustained cytotoxicity, meaning cell-killing activity, and memory-like responses. Immune activation was observed in cells obtained from cancer patients as well as healthy-donor models.

What tolerability and half-life results did BriaPro report for BP-80?

BP-80 demonstrated a no observed effect level of 50 mg/kg/day and a half-life ranging from 8.08 to 8.92 hours in cynomolgus monkeys. These were preclinical animal findings.

What conditions did BP-80 require for activity in BriaPro’s cell-based assays?

BP-80’s CD28 co-stimulatory activity depended on Fc receptor engagement, while counteracting CTLA-4-mediated inhibition depended on anti-Fc antibody-based crosslinking. These dependencies applied to the respective cell-based assay findings.