CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 175 enrolled
Drug / intervention
CPI-1205 +4 moredrug
Likely dose
CPI-1205 400 mgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT03480646
NCT03480646Phase 2Completed

A Phase 1b/2 Study of CPI-1205, a Small Molecule Inhibitor of EZH2, Combined With Enzalutamide or Abiraterone/Prednisone in Patients With Metastatic Castration Resistant Prostate Cancer

Constellation Pharmaceuticals·interventional·Posted Mar 29, 2018·Updated Oct 29, 2025

In Brief

A Phase 2 clinical trial evaluating CPI-1205, Cobicistat, and 3 other interventions for Metastatic Castration Resistant Prostate Cancer (mCRPC). Completed, enrolled 175 participants across 41 sites.

Detailed Summary

This was an open-label Phase 1b/2 study involving oral administration of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone in male patients with metastatic Castration-Resistant Prostate Cancer. The study was designed to determine the maximum tolerated dose (MTD) and the recommended Phase II dose (RP2D) based on the safety, tolerability, pharmacokinetic, and efficacy profiles of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone. Following the determination of the MTD and RP2D, the study proceeded to Phase 2. Patients in Phase 2 received CPI-1205 at the RP2D in combination with either enzalutamide or abiraterone/prednisone versus either enzalutamide or abiraterone/prednisone as a control arm.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited States
Collaborators--

Timeline

Phase 2CompletedFinished
201820192020202120222023202420252026
First PostedMar 29, 2018
Enrollment StartNov 15, 2017
Primary CompletionFeb 3, 2021
TodayJul 2, 2026
Enrollment to primary: 3.2 yearsPosted 8.3 years ago

Interventions

CPI-1205drug

CPI-1205: Either 400 mg BID or 800 mg TID during Phase 1 dose-escalation and RP2D, 800 mg TID, for Phase 2

Cobicistatdrug

Cobicistat 150 mg PO BID

Enzalutamidedrug

Enzalutamide 160mg PO QD

Abirateronedrug

Abiraterone 1000mg PO QD

Prednisonedrug

Prednisone 5mg PO BID