BriaCell Therapeutics Corp. reported preliminary disease control rate of 61% in evaluable (i.e. exhibited clinical outcomes) Phase 2 advanced breast cancer patients treated with BriaCell's Bria-IMTTM regimen - the same formulation being used in BriaCell's open pivotal Phase 3 study. Additionally, a disease control rate of 50% was reported in similarly treated evaluable patients who had failed prior antibody-drug conjugate (ADC) therapy.

Background: Advanced metastatic breast cancer patients who have had multiple lines of prior treatments including ADCs, are often recommended palliative, supportive medical care that focuses on easing pain, stress and other symptoms of a serious/terminal illness. The patient was hormone receptor positive HER 2 negative (HR+/HER2-), had failed four prior lines of therapy including ADC therapy and had breast cancer metastasized to her liver. She had two HLA matches with Bria-IMTTM and received seven cycles of treatments with the Bria-IMTTM regimen.

Results: In her first on study assessment the liver metastasis was no longer seen. She had progression free survival (PFS) of 5.8 months, a 100% increase from her PFS on ADC therapy. BriaCell Clinical Data in Evaluable Patients Bria-IMTTM Combined with an Immune Check Point Inhibitor Among the 35 patients with evaluable outcomes in BriaCell's ongoing Phase 2 study, 23 patients were treated with the same Bria-IMTTM formulation currently being used in BriaCell's Phase 3 metastatic breast cancer study.

These patients had been heavily pre-treated and had failed a median number of six prior regimens. Results in Evaluable Patients: Disease control rate of 61%; defined as the percentage of patients who achieve a complete response, partial response, or stable disease. Disease control rate of 50% in the 10 patient subset who had failed prior ADC therapy.

This compares favorably with reported literature for second ADC treatment in ADC failure patients (approximately 20-42%). Progression free survival of 4.2 months in ADC failure patients is also very favorable in comparison to published data in similar patients (1.6-3.3 months). No discontinuations due to drug toxicity reported.

No cases of Interstitial Lung Disease (ILD) with Bria-IMTTM (a well-documented serious side effect of ADCs) reported in this group of patients. The strong survival and clinical benefits observed in evaluable and ADC resistant patients support the use of the current formulation in BriaCell's pivotal Phase 3 study and the Company looks forward to presenting further updates as treatment progresses in the fully enrolled Phase 2 study.