At a glance
ClinicalIndex Comparison Record- ✓Histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology (Cohorts A, B, C, D, E, G, J)
- ✓≥1% neuroendocrine cells with Small cell carcinoma, LCNEC, or Mixed NE carcinoma morphology confirmed by central pathology (Cohorts F, H, I)
- ✓Tumor tissue from non-irradiated site with cohort-specific biopsy requirements
- ✓Prostate cancer progression within 6 months prior to screening via PSA, radiographic soft tissue, or bone progression (except de novo NE)
- ✕Prior anticancer monoclonal antibody within 4 weeks or unrecovered toxicity from earlier mAbs
- ✕Chemotherapy, targeted small molecule, abiraterone, enzalutamide, or radiation within 2 weeks or unrecovered toxicity
- ✕Currently participating in investigational study or received investigational drug within 4 weeks of randomization
- ✕Immunodeficiency or systemic steroid/immunosuppressive therapy within 7 days of randomization
Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.
Phase Ib/II Trial of Pembrolizumab (MK-3475) Combination Therapies in Metastatic Castration-Resistant Prostate Cancer (mCRPC) (KEYNOTE-365)
In Brief
A Phase 1 clinical trial evaluating Pembrolizumab 200 mg, Olaparib 400 mg, and 11 other interventions for Metastatic Castration-Resistant Prostate Cancer. Active but no longer recruiting, targeting 1,200 participants across 14 sites in 9 countries.
Signals
Detailed Summary
The purpose of this study is to assess the safety and efficacy of pembrolizumab (MK-3475) combination therapy in participants with metastatic castration resistant prostate cancer (mCRPC). There will be ten cohorts in this study: Cohort A will receive pembrolizumab + olaparib, Cohort B will receive pembrolizumab + docetaxel + prednisone, Cohort C will receive pembrolizumab + enzalutamide, Cohort D will receive pembrolizumab + abiraterone + prednisone Cohort E will receive pembrolizumab+lenvatinib, Cohort F will receive pembrolizumab+lenvatinib, Cohort G will receive pembrolizumab/vibostolimab coformulation (MK-7684A), Cohort H will receive pembrolizumab/vibostolimab coformulation, Cohort I will receive pembrolizumab+carboplatin+etoposide in Arm 1 and carboplatin+etoposide in Arm 2 and Cohort J will receive belzutifan in Arm1 and Pembrolizumab+belzutifan in Arm 2. Outcome measures will be assessed individually for each cohort.
Study Details
Timeline
Arms & Interventions
Participants with adenocarcinoma (AC) mCRPC in Cohort A will receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 3-week dosing cycle (Q3W) and olaparib 400 mg capsules or 300 mg tablets by mouth (PO) twice a day (BID) continuously from Day 1 of Cycle 1. Treatment with pembrolizumab will continue until progression or a maximum of 35 treatment cycles (up to 2 years). Treatment with olaparib will continue until progression. Participants who must discontinue 1 of the 2 drugs in the combination due to adverse events may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort B will receive pembrolizumab 200 mg IV on Day 1 Q3W, docetaxel 75 mg/m\^2 IV on Day 1 Q3W, and prednisone 5 mg tablet PO BID continuously from Day 1 of Cycle 1. Participants will only be permitted to receive a maximum of 10 cycles of docetaxel and prednisone. Treatment with pembrolizumab will continue for a maximum of 35 cycles (up to 2 years) or until progression. Participants who must discontinue 1 of the 2 drugs due to adverse events in the combination may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort C will receive pembrolizumab 200 mg IV on Day 1 Q3W and enzalutamide 160 mg PO every day (QD) continuously from Day 1 of Cycle 1. Treatment with pembrolizumab will continue until progression or a maximum of 35 treatment cycles (up to 2 years). Treatment with enzalutamide will continue until progression. Participants who must discontinue 1 of the 2 drugs in the combination due to adverse events may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort D will receive pembrolizumab 200 mg IV on Day 1 Q3W, abiraterone acetate 1000 mg PO QD and prednisone 5 mg tablet PO BID continuously from Day 1 of Cycle 1. Treatment with pembrolizumab will continue for a maximum of 35 cycles (up to 2 years) or until progression. Participants who must discontinue 1 of the 2 drugs due to adverse events in the combination may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort E will receive pembrolizumab 200 mg IV on Day 1 Q3W, and lenvatinib 20 mg PO QD continuously from Day 1 of Cycle 1. Treatment with pembrolizumab will continue for a maximum of 35 cycles (up to 2 years) or until progression. Participants who must discontinue 1 of the 2 drugs due to adverse events in the combination may continue the study with the other combination drug.
Participants with neuroendocrine (t-NE) mCRPC in Cohort F will receive pembrolizumab 200 mg IV on Day 1 Q3W, and lenvatinib 20 mg PO QD continuously from Day 1 of Cycle 1. Treatment with pembrolizumab will continue for a maximum of 35 cycles (up to 2 years) or until progression. Participants who must discontinue 1 of the 2 drugs due to adverse events in the combination may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort G will receive a coformulation fixed dose combination of 200 mg pembrolizumab and 200 mg vibostolimab (MK-7684) Q3W IV from Day 1 of Cycle 1. Treatment will continue for a maximum of 35 cycles (up to 2 years) or until progression.
Participants with t-NE mCRPC in Cohort H will receive a coformulation fixed dose combination of 200 mg pembrolizumab and 200 mg vibostolimab (MK-7684) Q3W IV from Day 1 of Cycle 1. Treatment will continue for a maximum of 35 cycles (up to 2 years) or until progression.
Participants with neuroendocrine mCRPC in Cohort I Arm 1 will receive pembrolizumab 200 mg IV on Day 1 Q3W + carboplatin titrated to an area under the plasma drug concentration-time curve \[AUC\] 5 IV on Day 1 Q3W + etoposide 100 mg/m\^2 IV on Days 1, 2, and 3 Q3W. Treatment with pembrolizumab will continue for a maximum of 35 cycles (up to 2 years) or until progression. Treatment with carboplatin+etoposide will continue for a maximum of 4 cycles (up to 2.8 months). Participants who must discontinue 1 or 2 of the 3 drugs due to adverse events in the combination may continue the study with the other combination drug/drugs.
Participants with neuroendocrine mCRPC in Cohort I Arm 2 will receive carboplatin titrated to an area under the plasma drug concentration-time curve \[AUC\] 5 IV on Day 1 Q3W + etoposide 100 mg/m\^2 IV on Days 1, 2, and 3 Q3W. Treatment will continue for a maximum of 35 cycles (up to 2 years) or until progression. Treatment with carboplatin+etoposide will continue for a maximum of 4 cycles (up to 2.8 months). Participants who must discontinue 1 of the 2 drugs due to adverse events in the combination may continue the study with the other combination drug.
Participants with AC mCRPC in Cohort J will receive belzutifan 120mg QD in the initial cohort. If an efficacy signal is detected in this arm based on a totality of evidence, Cohort J may be expanded further where participants will be randomized 1:1 to receive either belzutifan 120 mg QD or belzutifan 120 mg QD and pembrolizumab 200 mg Q3W. Treatment will continue for a maximum of 35 cycles (up to 2 years) or until progression.
Participants with AC mCRPC in Cohort J will receive belzutifan 120mg QD in the initial cohort. If an efficacy signal is detected in this arm based on a totality of evidence, Cohort J may be expanded further where participants will be randomized 1:1 to receive either belzutifan 120 mg QD or belzutifan 120 mg QD and pembrolizumab 200 mg Q3W. Treatment will continue for a maximum of 35 cycles (up to 2 years) or until progression.
Interventions
IV Q3W
Eight 50-mg capsules PO BID
IV Q3W
One 5-mg tablet PO BID
Four 40-mg capsules, four 40-mg tablets, or two 80-mg tablets PO QD
Premedication for Cohort B given PO at 12, 3, and 1 hours prior to docetaxel infusion Q3W
Two 150-mg tablets PO BID
Two 500-mg or four 250-mg tablets PO QD
20 mg PO QD
IV Q3W
IV Q3W
IV on Days 1, 2 and 3 of each cycle
PO QD