Phase 3 Trial of Ifinatamab Deruxtecan Initiated in Patients with Pretreated Metastatic Castration-Resistant Prostate Cancer

Daiichi Sankyo and Merck have initiated the IDeate-Prostate01 phase 3 trial to evaluate the efficacy and safety of ifinatamab deruxtecan versus docetaxel in patients with metastatic castration-resistant prostate cancer. Ifinatamab deruxtecan is a B7-H3 directed antibody drug conjugate discovered by Daiichi Sankyo and jointly developed with Merck. The trial aims to improve outcomes for patients with previously treated mCRPC, where survival decreases to 31%.

Daiichi Sankyo and Merck have launched the IDeate-Prostate01 phase 3 trial to assess the efficacy and safety of ifinatamab deruxtecan (I-DXd) compared to docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC). This trial is part of a broader effort to improve outcomes for patients with previously treated mCRPC, where the five-year survival rate significantly decreases to 31%.

The IDeate-Prostate01 trial is a multicenter, open-label, randomized study evaluating the safety and efficacy of I-DXd versus docetaxel plus corticosteroid. Eligible patients must have received prior treatment with one or two androgen receptor pathway inhibitors and experienced disease progression during or after at least eight weeks of treatment. The primary endpoints include overall survival and radiographic progression-free survival, with secondary endpoints focusing on objective response rate, time to first subsequent therapy, and safety.

I-DXd is a B7-H3 directed antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed with Merck. It is designed using Daiichi Sankyo’s proprietary DXd ADC Technology, which attaches a humanized anti-B7-H3 IgG1 monoclonal antibody to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers. The trial aims to evaluate whether I-DXd may replace standard taxane-based chemotherapy as a potential treatment strategy in mCRPC patients.

The IDeate-Prostate01 trial follows promising results from the IDeate-PanTumor01 phase 1/2 trial, which showed promising responses in heavily pretreated patients with mCRPC. The trial will enroll approximately 1,440 patients across Asia, Europe, North America, and Oceania, with results expected to contribute significantly to the advancement of prostate cancer treatment.

References:
[1] https://www.merck.com/news/ideate-prostate01-phase-3-trial-of-ifinatamab-deruxtecan-initiated-in-patients-with-pretreated-metastatic-castration-resistant-prostate-cancer/