DSMB Recommends Continuation of Bria-IMT Investigation in Metastatic Breast Cancer

An independent data safety monitoring board (DSMB) has issued its sixth consecutive positive recommendation for the continuation of the phase 3 BRIA-ABC trial (NCT06072612) investigating Bria-IMT plus an immune checkpoint inhibitor (ICI) in patients with metastatic breast cancer, after identifying no safety concerns associated with safety data from the trial.¹

The DSMB has recommended the trial to continue without modifications. Notably, the conduction of quarterly DSMB meetings is part of the BRIA-ABC study protocol.

“We are highly encouraged by the sixth consecutive positive recommendation of the DSMB for continuation of BriaCell’s pivotal phase 3 BRIA-ABC study,” William V. Williams, MD, president and chief executive officer of BriaCell, stated in a news release. “This important milestone represents another step forward in advancing BriaCell’s novel immunotherapy approaches for patients with urgent unmet medical needs.”

What is the design of the BRIA-ABC trial?

This multicenter, randomized, open-label trial is enrolling patients at least 18 years of age with histologically confirmed breast cancer that is either locally recurrent and unresectable or has metastatic lesions.² Patients must have progressed on prior therapy. Those with persistent disease and local recurrence must not be amenable to local treatment. Select patients with late-stage metastatic breast cancer with no meaningful available alternative therapies are also being enrolled. All patients are required to have a life expectancy of at least 4 months and an ECOG performance status of 0 to 2.

The trial was designed for patients to be randomly assigned 1:1:1 to receive Bria-IMT plus ICIs, treatment of physician’s choice, or Bria-IMT monotherapy. After the first 150 patients were enrolled, the Bria-IMT monotherapy arm was discontinued, and patients were allowed to cross over to the Bria-IMT/checkpoint inhibition arm. At this point, randomization continued between the Bria-IMT/checkpoint inhibition and treatment of physician’s choice arms.

Patients in the Bria-IMT arms receive cyclophosphamide at 300 mg/m² on days –2 or –3 followed by intradermal treatment with the SV-BR-1-GM breast cancer cell line divided into 4 inoculations starting on day 0; on days 1 through 3, checkpoint inhibition with retifanlimab-dlwr (Zynyz) at 375 mg plus interferon is given intradermally within each SV-BR-1-GM inoculation site. Treatment of physician’s choice consists of eribulin, carboplatin, capecitabine, gemcitabine, vinorelbine or taxanes.

Overall survival serves as the trial’s primary end point. Key secondary end points include progression-free survival, clinical benefit rate, overall response rate, quality of life, and central nervous system event-free survival.

What is the mechanism of action of the Bria-IMT regimen?

Bria-IMT is a combination immunotherapy regimen that is made up of the SV-BR-1-GM allogeneic whole cancer vaccine administered with an ICI.³ The SV-BR-1-GM breast cancer cell line portion of the Bria-IMT regimen promotes antitumor activity by expressing tumor-associated antigens and secreting granulocyte-macrophage colony–stimulating factor, which promotes adaptive immune responses mediated by T cells, promotes innate immune responses mediated by dendritic and natural killer cells, and enhances the activation of dendritic cells.⁴ SV-BR-1-GM cells are also designed for optimal immune recognition via patient-specific human leukocyte antigen matching, as well as CD4-positive T-cell activation. The addition of a checkpoint inhibitor to SV-BR-1-GM has also been shown to overcome the suppressive tumor microenvironment.³

What findings have been previously seen with Bria-IMT plus checkpoint inhibition in metastatic breast cancer?

A phase 1/2 trial (NCT03328026) investigated Bria-IMT at various dose level and schedules in 54 patients with various subtypes of metastatic breast cancer. Efficacy outcomes in the cohort of patients who received Bria-IMT at the phase 3 formulation (which did not include interferon gamma; n = 37) were comparable with those seen in the treatment of physician’s choice arms of the phase 3 ASCENT (NCT02574455) and TROPiCS-02 (NCT03901339) trials.

References

1. BriaCell receives positive recommendation from data safety monitoring board (dsmb) for phase 3 study in metastatic breast cancer. News release. BriaCell Therapeutics Corp. May 26, 2026. Accessed May 26, 2026. https://www.globenewswire.com/news-release/2026/05/26/3300964/0/en/briacell-receives-positive-recommendation-from-data-safety-monitoring-board-dsmb-for-phase-3-study-in-metastatic-breast-cancer.html
2. Study of the Bria-IMT regimen and CPI vs physicians’ choice in advanced metastatic breast cancer. (BRIA-ABC). ClinicalTrials.gov. Updated April 7, 2026. Accessed May 26, 2026. https://clinicaltrials.gov/study/NCT06072612
3. Chumsri S, Nangia CS, Barve MA, et al. Bria-IMT + checkpoint inhibitor: phase I/II survival results compared to benchmark trials in metastatic breast cancer. J Clin Oncol. 2025;43(suppl 16):1096. doi:10.1200/JCO.2025.43.16_suppl.1096
4. Chumsri S, O’Shaughnessy J, Ali A, et al. Update on phase III pivotal trial of Bria-IMT + CPI vs physician’s choice in advanced metastatic breast cancer (BRIA-ABC). J Clin Oncol. 2025;43(suppl 16):TPS1138. doi:10.1200/JCO.2025.43.16_suppl.TPS1138