• A Phase II trial evaluating ESK981, a multi-tyrosine kinase inhibitor, combined with nivolumab in metastatic castration-resistant prostate cancer (mCRPC) was terminated due to futility.
• The combination therapy of ESK981 and nivolumab did not demonstrate significant antitumor activity in patients with AR-positive mCRPC, showing a maximum PSA decline of only 14% in one patient.
• The median radiographic progression-free survival (rPFS) was 3.7 months, and the median overall survival (OS) was 9.6 months, indicating limited clinical benefit from the treatment regimen.
• Grade 3 treatment-related adverse events, including fatigue, anemia, and lymphopenia, were observed, further questioning the risk-benefit profile of this combination in mCRPC.