Researchers have reported positive early results for acasunlimab, a bispecific T-cell engager targeting PSMA and CD3, in treating metastatic castration-resistant prostate cancer (mCRPC). The findings were presented at the 2024 ASCO Genitourinary Cancers Symposium.
The Phase I study enrolled 34 men with mCRPC who had previously received second-generation androgen receptor therapy and a taxane. Participants were heavily pretreated, having received a median of four prior lines of therapy. Acasunlimab, developed by Astellas, aims to redirect T cells to attack PSMA-positive prostate cancer cells.
Interim results revealed a 34% confirmed PSA response rate among men given doses of 20 μg or higher. Among 21 patients in this group, three achieved partial radiographic responses as assessed by RECIST criteria. The disease control rate in these patients was 76%.
“These are encouraging early signs that immune redirection with bispecifics may play a meaningful role in advanced prostate cancer,” said Dr. Neeraj Agarwal, principal investigator of the study.
The drug was generally manageable in terms of safety. Cytokine release syndrome (CRS) was the most common treatment-related adverse event, occurring in 53% of patients. All cases of CRS were Grade 1 or 2 and resolved without needing intensive interventions. Other adverse effects included fever and fatigue.
Enrollment in the dose expansion part of the study is ongoing, with further research planned to refine dosing and evaluate long-term benefits.
