Findings from a phase 3 trial of the Bria-IMT regimen showed a 71% intracranial objective response rate in patients with breast cancer and central nervous system metastases.
The Bria-IMT regimen demonstrated a 71% intracranial objective response rate (n = 5/7) in patients with advanced breast cancer who have central nervous system (CNS) metastases, according to findings from the phase 3 BRIA-ABC trial (NCT06072612).1
The regression of CNS metastases was seen in heavily pretreated patients across all breast cancer subgroups. In this study cohort, patients were heavily pretreated patients and had disease progression after receiving multiple lines of therapy, including 1 who progressed on treatment with 2 antibody-drug conjugates.
BriaCell plans to conduct an additional subgroup analysis.
“We have accumulated positive clinical responses in five patients with intracranial metastases, which generally are extremely difficult to treat, and have a very poor prognosis. This antitumor activity furthers our excitement in our ongoing phase 3 pivotal trial studying the Bria-IMT regimen in advanced breast cancer,” stated William V. Williams, MD, president and chief executive officer of BriaCell, in a press release.
Bria-IMT is an off-the-shelf targeted cellular immunotherapy for the treatment of advanced metastatic breast cancer. The regimen includes SV-BR-1-GM, a proprietary and experimental allogeneic whole-cell breast tumor cell line. It is transfected with the CSF2 gene encoding GM-CSF to stimulate dendritic cell activity.2 Bria-IMT was granted FDA fast track designation in October 2023.3
The phase 3 BRIA-ABC trial has an estimated enrollment of 404 patients. Patients are randomized into 1 of 3 groups to receive Bria-IMT plus a checkpoint inhibitor (CPI), retifanlimab-dlwr (Zynyz), Bria-IMT alone, or an active comparator of physician’s choice. The Bria-IMT regimen consists of 300 mg/m2 of cyclophosphamide on day –2 and 4 intradermal inoculations of SV-BR-1-GM on day 0. Patients in the Bria-IMT plus CPI arm receive retifanlimab 375 mg infusion on days 1-3 plus intradermal interferon injections, while patients in the Bria-IMT arm only receive the interferon injects on days 1-3. Patients in the active comparator arm can receive eribulin, carboplatin, capecitabine, gemcitabine, vinorelbine, or taxanes.4
The primary end point is overall survival. The secondary end points are progression-free survival, clinical benefit rate, overall response rate, and quality of life.
Patients are eligible to participate if they have histological confirmation of breast cancer with locally recurrent or metastatic lesions, failed prior therapy, an expected survival of at least 4 months, and an ECOG performance status of 0-2. Patients are not eligible for participation if they have received systemic treatment or major surgery within 21 days of the first study dose, received radiotherapy within 14 days of the first study dose, New York Heart Association stage 3 or 4 cardiac disease, known concurrent malignancy, or a diagnosis of immunodeficiency.