Bellicum Pharmaceuticals presents early Phase 1 results for BPX-601

Bellicum Pharmaceuticals will present early Phase 1 results for BPX-601 at the American Society of Clinical Oncology Genitourinary Cancers Symposium, ASCO GU, in San Francisco and virtually. The poster titled "Early Results from a Phase 1, Multicenter Trial of PSCA-Specific GoCAR T Cells in Patients with Metastatic Castration-Resistant Prostate Cancer" presents initial data from the first two cohort treated with BPX-601. These interim results demonstrated preliminary efficacy of BPX-601 PSCA-directed GoCAR-T cells in combination with rimiducid in heavily pre-treated patients. "We believe these encouraging initial clinical results in mCRPC support the potential of BPX-601 and the GoCAR-T platform," stated Rick Fair, President and Chief Executive Officer, Bellicum Pharmaceuticals. "We designed the GoCAR-T platform to enhance immune cell proliferation and persistence, resist exhaustion, and override key inhibitory factors in the solid tumor microenvironment. We are excited to share data supporting the clinical activity of the first GoCAR-T program early in dose escalation, and look forward to reporting additional results as we work to optimize the doses of BPX-601 cells and rimiducid." Initial Results from Ongoing BPX-601 Phase 1 Trial. The primary observations were: Four of eight patients achieved a PSA50 response, three of whom achieved a PSA90 response. Of the six patients with soft tissue disease, two achieved partial responses by RECIST v1.1, one of which was confirmed. Of the two patients with bone-only disease, one patient achieved a PSA90 response with decreased enhancement of bone lesions observed on bone scan. The most common grade 3+ adverse events were myelosuppression, characteristic of the lymphodepleting chemotherapies used in CAR-T studies. Two patients experienced Grade 3 cytokine release syndrome. Consistent BPX-601 cell expansion across patients was observed, with persistence of BPX-601 cells detected in peripheral blood over 200 days. Evidence of inducible MyD88/CD40 activation was observed, with serum levels of pro-inflammatory T cell cytokines rising after administration of rimiducid and subsequently falling prior to subsequent doses. BPX-601 cell infiltration in PSCA-positive tumor was observed.