Dr. William Williams reports

BRIACELL REPORTS UNPRECEDENTED PRELIMINARY SURVIVAL AND CLINICAL BENEFIT IN ANTIBODY-DRUG CONJUGATE (ADC) REFRACTORY PATIENT SUBSET

Briacell Therapeutics Corp. has released unprecedented preliminary survival and clinical benefit data in a new subset of advanced breast cancer patients treated with Briacell's Bria-IMT regimen: patients that have developed resistance to (and failed to respond to) antibody-drug conjugates (ADCs).

ADCs have significantly advanced cancer therapy in the past few years; however, many patients experience serious side effects and others develop resistance to ADCs; therefore, their medical needs remain unmet.

"We are excited with our findings of unprecedented survival and clinical benefit in very difficult-to-treat patients who failed ADCs and view our findings as a significant clinical breakthrough in the field of cancer therapy. This is highly encouraging given our ongoing pivotal study is investigating the effects of Bria-IMT regimen in advanced breast cancer with overall survival as its primary end point," stated Dr. William V. Williams, Briacell's president and chief executive officer. "Armed with our novel immunotherapy, we are hoping to make a meaningful contribution to the lives of patients who have failed ADCs across all breast cancer types."

Briacell clinical data in ADC refractory patients

Bria-IMT combined with an immune check point inhibitor:

• In a subset of Briacell's continuing phase 2 study, clinical data of 23 advanced metastatic breast cancer patients who failed prior treatments with ADCs were analyzed. Four patients had prior treatments with Kadcyla; 13 had prior treatments with Enhertu; 13 with Trodelvy, of which seven of these patients were treated with multiple agents (totalling 23 patients). In addition, seven of these 23 patients had also failed prior treatment with immune checkpoint inhibitors.
• Heavily pretreated metastatic breast cancer patients had a median number of six prior treatments.
• Kaplan-Meier analysis showed median overall survival (OS) that was up to twice that reported in the literature, with some patients recording survival of over a year.
• Disease control rate of 40 per cent was observed in evaluable patients further indicating clinical benefit.
• Progression-free survival (PFS) was similar or better than that of the patients' prior therapy in 40 per cent of patients, highlighting clinical benefit and tolerability of the Bria-IMT regimen.
• Seventeen of 23 patients remain alive as of today, suggesting efficacy, tolerability and survival benefit of Briacell's Bria-IMT regimen. The data will continue to mature as patients remain on the study.
• All patients received Briacell's therapy with no toxicity-related discontinuations.
• Importantly, there were no cases of interstitial lung disease (ILD) with Bria-IMT -- a well-documented serious side effect of ADCs.

About Briacell Therapeutics Corp.

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

We seek Safe Harbor.