BriaCell Shares Clinical Data at ASCO 2024

BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXW) (TSX: BCT), a clinical-stage biotechnology company specializing in novel immunotherapies for cancer treatment, has announced positive data from its ongoing randomized Phase 2 study of Bria-IMT™ in patients with advanced metastatic breast cancer. These findings were presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL.

BriaCell's Bria-IMT™ demonstrated significant clinical efficacy, doubling the progression-free survival (PFS) and clinical benefit rate (CBR) compared to historical results in literature for similar patients. The therapy showed promising results in patients resistant to antibody-drug conjugates (ADCs), with 48% of these patients exhibiting favorable PFS outcomes when compared to their most recent treatment.

The clinical data highlighted the potential of Bria-IMT™ as a well-tolerated treatment option, with no Bria-IMT™ related discontinuations reported. "The clinical efficacy and safety data are impressive, especially given the limited treatment options and the significant toxicities associated with available therapies," said Dr. Saranya Chumsri, the Principal Investigator and Professor of Oncology at Mayo Clinic.

The efficacy of Bria-IMT™ is underscored by its unique mechanism of action, which selectively activates both adaptive and innate immune responses, thereby enhancing the immune system's ability to fight cancer without causing severe side effects. Dr. Carmen Calfa, Clinical Research Lead for the breast site disease group at the University of Miami Miller School of Medicine, emphasized the therapy's ability to activate cancer-fighting CD4+ and CD8+ T cells, and innate responses such as dendritic and NK cells.

The Phase 2 study included 54 heavily pretreated patients who had failed multiple prior therapies. Comparative analysis showed that the Phase 3 formulation of Bria-IMT™ not incubated with interferon gamma significantly improved PFS. Among these, the clinical benefit was observed in 55% of evaluable patients across different subtypes of breast cancer.

The Phase 3 study will compare Bria-IMT™ in combination with an immune checkpoint inhibitor (CPI) to the treatment of the physician’s choice (TPC). Subgroup analysis revealed that Bria-IMT™ provides a clinical benefit across multiple breast cancer subtypes, including HR+/HER2-, HER2+, and HR-/HER2 low subtypes. The treatment exhibited a median PFS of 4.1 months, which is substantially higher compared to similar studies, suggesting superior clinical efficacy despite the patients having undergone a median of six prior treatments.

In terms of safety, Bria-IMT™ was well-tolerated, with no instances of interstitial lung disease (ILD) or related treatment discontinuations. This reinforces its favorable safety profile, making it a viable option for patients who have exhausted other treatment avenues.

Furthermore, Bria-IMT™ showed efficacy in reducing intracranial metastases, with an 83% intracranial objective response rate in evaluable patients. This is particularly significant given the poor prognosis associated with central nervous system (CNS) metastases in breast cancer. The observed tumor reductions in these patients highlight the potential of Bria-IMT™ in managing CNS metastatic disease.

BriaCell is eager to continue monitoring the data from the ongoing pivotal Phase 3 study, particularly focusing on ADC-resistant and CNS metastatic disease subgroups. The company aims to position Bria-IMT™ as a breakthrough treatment option for advanced metastatic breast cancer, addressing significant unmet medical needs.

In summary, BriaCell’s Bria-IMT™ has demonstrated remarkable clinical efficacy and safety in heavily pretreated metastatic breast cancer patients, offering improved progression-free survival and clinical benefits. The ongoing Phase 3 study will further evaluate its potential as a novel immunotherapy for this challenging condition.