Title
Merck MK2400-001 A Phase 3, Open-label Study of Ifinatamab Deruxtecan Versus Docetaxel in Participants with Metastatic Castration-Resistant Prostate Cancer (mCRPC) (IDeate-Prostate01)

Description
Researchers are looking for new ways to treat metastatic castration-resistant prostate cancer (mCRPC). Researchers have designed a study medicine called ifinatamab deruxtecan (also called I-DXd or MK-2400) to treat mCRPC. The goal of this study is to learn if people who receive I-DXd live longer overall and live longer without the cancer growing or spreading than people who receive chemotherapy,

Objective
Primary:
-To compare ifinatamab deruxtecan (I-DXd) to docetaxel with respect to overall survival (OS) in participants with mCRPC.
-To compare I-DXd to docetaxel with respect to radiographic progression free survival (rPFS) per Prostate Cancer Working Group (PCWG) Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as assessed by blinded independent central review (BICR) in participants with mCRPC.

Secondary:
-To evaluate the TFST of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the OR and DOR per PCWG Modified RECIST 1.1 as assessed by BICR of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the Time to Pain Progression (TTPP) of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the time to PSA progression of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the PSA response rate of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the time to first SSRE of participants treated with I-DXd compared with participants treated with docetaxel.
-To evaluate the safety and tolerability of I-DXd.

Treatment Each participant will participate in the study for approximately 2 years. After screening, each participant will be assigned to receive study intervention until one of the conditions for discontinuation of study intervention is met. Participants assigned to receive docetaxel will receive study intervention for up to 10 cycles. Participants who discontinue for reasons other than BICR-verified radiographic disease progression will have post treatment follow-up imaging for disease status until any of the conditions for discontinuation of imaging are met. After the end of treatment, each participant will be followed for the occurrence of AEs, SAEs, and other reportable safety events. In addition, all participants will be followed for overall survival until death, withdrawal of consent, the end of the study, or enrollment into an extension study.

Key Eligibility Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

Has diagnosis of metastatic castration-resistant prostate cancer (mCRPC)

Has prostate cancer progression while on androgen deprivation therapy (ADT) (or post bilateral orchiectomy) within 6 months prior to entering the study

Has received prior treatment with 1 or 2 androgen receptor pathway inhibitor (ARPI) and progressed during or after at least 8 weeks of treatment

History of (non-infectious) interstitial lung disease (ILD)/pneumonitis that required steroids

Has uncontrolled or significant cardiovascular disease

Has received prior treatment with a taxane-based chemotherapy agent for mCRPC

Applicable Disease Sites
Prostate

Participating Institutions
UW Health Eastpark Medical Center; UW Health University Hospital