A Phase 1/2 interventional study of Docetaxel and Ifinatamab Deruxtecan in Castration-Resistant Prostatic Cancer and Metastasis, sponsored by Merck Sharp & Dohme LLC. Recruiting at 82 sites in 19 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-06.
Sponsored by Merck Sharp & Dohme LLC · Phase 1/2, Interventional, and Treatment
The purpose of this substudy is to assess the efficacy and safety of ifinatamab deruxtecan (I-DXd), given alone or with other treatments in participants with metastatic castration-resistant prostate cancer (mCRPC). The goals of this study are to learn about:
This sub study MK-2400-01A assesses treatments for metastatic castration-resistant prostate cancer (mCRPC).
The master screening protocol is MK-2400-U01
84 studies on the registry are indexed under Prostatic Neoplasms, Castration-Resistant; 30 are open to participants now.
This study's planned enrollment of 360 is above the median of 82 across 61 interventional studies indexed under Prostatic Neoplasms, Castration-Resistant.
Browse Prostatic Neoplasms, Castration-Resistant studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,114 studies on the registry; 133 are open to participants now.
Of its 489 completed or terminated interventional studies of FDA-regulated products, 362 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
Participants will receive docetaxel at a determined dose every 3 weeks (Q3W) for a maximum of 10 cycles. Each cycle is 21 days.
Drug: Docetaxel
Participants will receive I-DXd at a determined dose Q3W until unacceptable toxicity, progressive disease (PD), death or withdrawal of consent.
Drug: Ifinatamab Deruxtecan · Drug: Rescue Medication
Following a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS opevesostat at a determined dose until any of the criterion for discontinuation of study intervention is met.
Drug: Ifinatamab Deruxtecan · Drug: Opevesostat · Drug: Rescue Medication
Following a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS ARPI (Androgen Receptor Pathway Inhibitor) - Abiraterone acetate OR Enzalutamide at a determined dose until any of the criterion for discontinuation of study intervention is met.
Drug: Ifinatamab Deruxtecan · Drug: Abiraterone · Drug: Enzalutamide · Drug: Rescue Medication
Administered via Intravenous (IV) infusion at a specified dose on specified days
Administered via IV infusion at a specified dose on specified days
Also known as: I-DXd, MK-2400, DS-7300a
Administered orally at a specified dose on specified days
Also known as: MK-5684, ODM-208
Administered orally at a specified dose on specified days
Administered orally at a specified dose on specified days
Before each dose of I-DXd, participants are required to take premedication for prevention of nausea and vomiting with a 2- or 3-drug combination regimen (eg, dexamethasone with either a 5-HT3 receptor antagonist or an NK-1 receptor antagonist as well as other drugs as indicated) per approved product label.
Efficacy Phase: Number of Participants Who Experience One or More Dose-Limiting Toxicities (DLTs) - Combination Arms Only
The following events if considered drug related by the Investigator, will be considered a DLT: Grade 4 nonhematologic toxicity (not based on laboratory value); Grade 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Grade 4 thrombocytopenia of any duration; Grade 3 thrombocytopenia associated with clinically significant bleeding; Nonhematologic AEs ≥Grade 3 with exceptions; Grade 3 or Grade 4 non-hematologic laboratory values if requires medical intervention, leads to hospitalization, persists for \>1 week, or results in a Drug-induced Liver Injury with exceptions; Grade 3 or 4 febrile neutropenia; Study intervention - related toxicities that lead to discontinuation of study treatment during Cycle 1; Prolonged delay (\>2 weeks) in initiating Cycles 2 due to treatment-related toxicity; Missing \>25% of study intervention doses as a result of treatment-related AE during Cycle 1; Grade 5 toxicity.
Time frame: Up to approximately 21 days
Efficacy Phase: Number of Participants Who Experienced an Adverse Event (AE)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Time frame: Up to approximately 54 months
Efficacy Phase: Number of Participants Who Discontinued Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Time frame: Up to approximately 24 months
Efficacy Phase: Prostate-Specific Antigen (PSA) response rate
PSA response is defined per prostate cancer working group (PCWG) criteria as a reduction in the PSA level of 50% or more from baseline measured at consecutive assessments at least 3 weeks apart.
Time frame: Up to approximately 54 months
Safety Lead-in Phase: Number of Participants Who Experience One or More Dose-Limiting Toxicities (DLTs) - Combination Arms Only
The following events if considered drug related by the Investigator, will be considered a DLT: Grade 4 nonhematologic toxicity (not based on laboratory value); Grade 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Grade 4 thrombocytopenia of any duration; Grade 3 thrombocytopenia associated with clinically significant bleeding; Nonhematologic AEs ≥Grade 3 with exceptions; Grade 3 or Grade 4 non-hematologic laboratory values if requires medical intervention, leads to hospitalization, persists for \>1 week, or results in a Drug-induced Liver Injury with exceptions; Grade 3 or 4 febrile neutropenia; Study intervention - related toxicities that lead to discontinuation of study treatment during Cycle 1; Prolonged delay (\>2 weeks) in initiating Cycles 2 due to treatment-related toxicity; Missing \>25% of study intervention doses as a result of treatment-related AE during Cycle 1; Grade 5 toxicity.
Time frame: Up to approximately 21 days
Safety Lead-in Phase: Number of Participants Who Experienced an Adverse Event (AE) - Combination Arms Only
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Time frame: Up to approximately 21 days
Safety Lead-in Phase: Number of Participants Who Discontinued Study Intervention Due to an AE - Combination Arms Only
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.
Time frame: Up to approximately 21 days
Objective Response Rate (ORR)
ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per PCWG3-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1). The percentage of participants who experience CR or PR as assessed by Blinded Independent Central Review (BICR) will be presented.
Time frame: Up to approximately 54 months
Radiographic Progression-Free Survival (rPFS)
rPFS is defined as the time from randomization to the first documented progressive disease (PD) per PCWG3-modified RECIST 1.1 based on BICR or death due to any cause, whichever occurred first. Per PCWG3-modified RECIST 1.1, PD is defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of one or more new lesions or ≥2 new bone lesions was also considered PD. PCWG3-modified RECIST is similar to RECIST 1.1 with the exception that a confirmation assessment of PD (\>4 weeks after the initial PD) is required for participants who remain on treatment following a documented PD per RECIST 1.1 and PCWG3 rules include new bone lesions. The rPFS per PCWG3-modified RECIST as assessed by BICR for all participants is presented. The nonparametric Kaplan-Meier method will be used to estimate the rPFS curve in each treatment arm
Time frame: Up to approximately 54 months
Overall Survival (OS)
Overall survival (OS) is defined as the time from randomization to death due to any cause. The nonparametric Kaplan-Meier method will be used to estimate the survival curves.
Time frame: Up to approximately 54 months
Duration of Response (DOR)
DOR is defined as the time from first documented evidence of CR or PR until progressive disease (PD) or death. Per PCWG3-modified RECIST 1.1, PD is defined as at least a 20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of ≥ 2 new bone lesions is also considered PD. DOR as assessed by BICR is presented. The nonparametric Kaplan-Meier method will be used to estimate the DOR in each treatment arm.
Time frame: Up to approximately 54 months
Time from allocation/randomization to initiation of the first subsequent anticancer therapy (TFST)
TFST is defined as the time from randomization to initiation of the first subsequent anticancer therapy or death, whichever occurs first. The nonparametric Kaplan-Meier method will be used to estimate the TFST in each treatment arm.
Time frame: Up to approximately 54 months
Time to Prostate-Specific Antigen (PSA) Progression
Time to PSA progression is defined as the time from randomization to PSA progression. Participants without PSA progression will be censored at the last PSA assessment date. The PSA progression date is defined as the date of: 1\) ≥25% increase and ≥2 ng/mL above the nadir, confirmed by a second value ≥3 weeks later if there is PSA decline from baseline, OR 2) ≥25% increase and ≥2 ng/mL increase from baseline beyond 12 weeks if there is no PSA decline from baseline.
Time frame: Up to approximately 54 months
Time to pain progression (TTPP)
The time from allocation/randomization to pain progression based on the Brief Pain Inventory-Short Form (BPI-SF) Item 3 "worst pain in 24 hours" and by the Analgesic Quantification Algorithm (AQA) score.
Time frame: Up to approximately 54 months
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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