BriaCell Therapeutics Corp. announced promising results from its Phase 1/2a clinical trial of Bria-OTS, a personalized off-the-shelf immunotherapy, in metastatic breast cancer (MBC). The first patient treated with Bria-OTS monotherapy experienced a complete resolution of lung metastasis after just two months (four doses) of treatment. This outcome offers renewed hope for patients with advanced breast cancer who have exhausted other treatment options.
The ongoing Phase 1/2a dose escalation study (ClinicalTrials.gov identifier: NCT06471673) is evaluating the safety and efficacy of Bria-OTS in patients with metastatic recurrent breast cancer. Bria-OTS represents a next-generation advancement of BriaCell’s lead candidate, Bria-IMT, which is currently in a pivotal Phase 3 study for MBC.
Clinical Response Details
The patient, a 78-year-old woman with hormone receptor-positive, HER2-negative metastatic breast cancer, had previously failed multiple lines of therapy. At enrollment on November 21, 2024, she presented with extensive metastases, including multiple bone, lymph node, and lung metastases. Following four injections of Bria-OTS every two weeks, the lung metastasis completely resolved, and the patient exhibited stable disease elsewhere. Notably, the treatment was well-tolerated, with no reported toxicity.
Expert Commentary
"Despite recent advancements in cancer treatment with antibody-drug-conjugates (ADCs) and immune check point inhibitors (CPIs), metastatic breast cancer remains an unmet medical need as many patients do not respond to these treatments," stated Dr. Neal Chawla, Associate Director of Clinical Research at the Sarcoma Oncology Center, and Principal Investigator for the Bria-OTS study. "We are very impressed by the clinical response observed showing rapid and robust clinical activity in addition to excellent tolerability in the first patient treated with Bria-OTS and look forward to reproducing these results in other cancer patients in the study."
Dr. William V. Williams, BriaCell’s President and CEO, added, "This data supports our hypothesis of personalized immunotherapy with Bria-OTS, potentially leading to new and effective treatment of metastatic breast cancer. We hope to transform the way we treat cancer patients with our novel personalized off-the-shelf immunotherapy approach."
Study Design and Future Directions
The Phase 1/2a clinical trial is designed to initially assess the safety and efficacy of Bria-OTS as a monotherapy. Subsequent phases will explore its use in combination with immune checkpoint inhibitors in metastatic breast cancer. Key inclusion criteria include patients with recurrent metastatic breast cancer who have experienced failure with at least two prior systemic therapies, such as chemotherapy. BriaCell also plans to evaluate Bria-OTS in other cancers, including prostate cancer, melanoma, and lung cancer.
