Dr. William Williams reports

BRIACELL 2023 SABCS POSTERS CONFIRM ACTIVATION OF CANCER-FIGHTING IMMUNE CELLS AND IDENTIFY POTENTIAL PREDICTORS OF CLINICAL BENEFIT

Briacell Therapeutics Corp. will present three posters, including two today at the 2023 San Antonio Breast Cancer Symposium at Henry B. Gonzalez Convention Center, San Antonio, Tex.

Today's posters highlight the activation of cancer-fighting immune cells by the Bria-IMT combination regimen that was identified using leading-edge technologies. These tools may be used to evaluate immune system responses to immunotherapy treatments, and perhaps to predict survival and clinical benefit in cancer patients treated with the Bria-IMT regimen.

"I am very excited with our findings using advanced CD8 ImmunoPET imaging that may be able to transform the way we treat cancer patients," stated Russ Kuker, MD, associate professor of clinical radiology at the University of Miami Miller School of Medicine and the first author of the PO1-20-12 poster. "We were able to see that the Bria-IMT combination regimen treatment can activate cancer-fighting T cells to infiltrate some breast cancer tumours. This represents evidence of the effectiveness of the Bria-IMT combination regimen and demonstrates the potential of this approach."

"I am thrilled with the successful transformation of a cold immune suppressed tumour to a hot immune responsive one, as well as the antibody responses seen with our immunotherapy," stated Dr. William V. Williams, Briacell's president and chief executive officer. "We strongly believe in the potential of our novel immunotherapy in cancer patients, and will be working determinedly with experts to bring these safe and effective treatment options to cancer patients who have failed other therapies."

Poster No. 1 abstract title:  CD8+ tumor-infiltrating lymphocytes turn a cold tumor hot in metastatic breast cancer

Submission ID:  1577766

Presentation ID:  PO1-20-12

Spotlight session:  poster session 1

Session date and time:  Wednesday, Dec. 6, 2023, at 12 p.m. to 2 p.m. CT

Bria-IMT combination regimen with immune checkpoint inhibitors activated cancer-fighting CD8+ T cells, turning cold tumours hot on ImmunoPET imaging:

• The company presents the first evidence that cold tumours can become hot with the Bria-IMT combination regimen treatment, suggesting immune system activation in the patient.
• CD8 ImmunoPET imaging, an imaging analysis technology, is used to mark CD8+ T-cells (also known as cytotoxic T cells) that are important components of the immune system, and key to cancer cell detection and destruction.
• The study demonstrated higher levels of cancer-fighting CD8+ tumour-infiltrating lymphocytes in some breast cancer metastatic sites and in lymphoid organs. This indicates activation of these cells and their invasion into the tumours, potentially leading to destruction of cancer cells.
• The company observed favourable changes in tumour markers (CEA and CA15-3), circulating tumor cells and cancer-associated macrophage-like cells, suggesting activation of tumour fighting cells.
• The company's findings support the use of Bria-IMT in combination with an immune check point inhibitor in its pivotal phase 3 study.

In summary, the use of leading technologies such as CD8 ImmunoPET imaging, peripheral blood tumour markers and circulating cancer-associated cells demonstrate the therapeutic potential of the Bria-IMT combination therapy regimen. These findings support the use of this combination regimen in the company's pivotal phase 3 study.

Poster No. 2 abstract title:  Analysis of antibody response to SV-BR-1-GM therapeutic vaccine in breast cancer patients using human protein microarrays: Potential correlations with therapy response

Submission ID:  1578637

Presentation ID:  PO2-13-06

Spotlight session:  poster session 2

Session date and time:  Wednesday, Dec. 6, 2023, at 5 p.m. to 7 p.m. CT

Highlights:

• Using protein array technology, the company was able to identify antibody responses that differed between clinical responders (defined as patients who achieved complete response, partial response or stable disease) and non-responders. Such responses may represent potential predictors of patients' survival following treatment with the Bria-IMT treatment regimen.
• The Bria-IMT regimen (both monotherapy and combination with an immune check point inhibitor) produced non-overlapping patterns in antibody profiles, suggesting the ability of the Bria-IMT combination therapy regimen to induce specific antibody responses.

Over all, Briacell's data show significant anti-tumour activity of its lead candidate, Bria-IMT (alone or in combination with immune check point inhibitors) in advanced metastatic breast cancer. Using innovative technologies, the company believes that it has identified potential predictors of patients' survival following treatment with the Bria-IMT combination therapy regimen. It plans to further investigate these findings in the company's continuing phase 3 study in advanced metastatic breast cancer.

Briacell's third poster of this meeting, titled "Randomized phase 2 of Bria-IMT, an allogenic human cell line with antigen presenting activity in heavily pretreated metastatic breast cancer," will present updated overall survival clinical data tomorrow at 12 p.m. to 2 p.m. CT; Presentation ID: PO3-05-12.

Copies of the posters will be available on the company's website.

About Briacell Therapeutics Corp.

Briacell is a clinical-stage biotechnology company that develops novel immunotherapies to transform cancer care.

We seek Safe Harbor.