ProSTAR: A Study Evaluating CPI-1205 in Patients With Metastatic Castration Resistant Prostate Cancer
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|ClinicalTrials.gov Identifier: NCT03480646|
Recruitment Status : Active, not recruiting
First Posted : March 29, 2018
Last Update Posted : March 11, 2020
This is a two-arm, open label Phase 1b/2 study with an oral administration of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone in male patients with metastatic Castration Resistant Prostate Cancer. This study is designed to determine the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) based on safety, tolerability, pharmacokinetic, and efficacy profiles of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone.
Following determination of MTD and RP2D will proceed to phase 2. Patients in phase 2 will receive CPI-1205 at the RP2D in combination with either enzalutamide or abiraterone/prednisone vs either enzalutamide or abiraterone/prednisone as a control arm.
|Condition or disease||Intervention/treatment||Phase|
|Metastatic Castration Resistant Prostate Cancer (mCRPC)||Drug: CPI-1205 Drug: Enzalutamide Drug: Abiraterone/Prednisone||Phase 1 Phase 2|
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||242 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||None (Open Label)|
|Official Title:||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|
|Actual Study Start Date :||November 15, 2017|
|Estimated Primary Completion Date :||August 2020|
|Estimated Study Completion Date :||August 2020|
|Experimental: CPI-1205 Combination with Enzalutamide||
|Experimental: CPI-1205 Combination with Abiraterone/Prednisone||
- Frequency of Dose-limiting toxicities (DLTs) [ Time Frame: 1 year ]The RP2D will be selected based on PK and the overall tolerability of each of the combinations (i.e with either enzalutamide or abiraterone/prednisone), but will not exceed the MTD.
- PSA50 [ Time Frame: 1 year ]The proportion of patients with a ≥50% reduction in PSA from baseline.
- CTC [ Time Frame: 1 year ]In patients who enter the trial with unfavorable CTCs (five or more cells per 7.5mL of blood), conversion to favorable status is defined as four or fewer cells per 7.5 mL of blood. The CTC conversion rate is the proportion of patients who convert to favorable status.
- CTC 30% Response Rate [ Time Frame: 1 year ]CTC 30% response is defined as a ≥30% reduction in CTCs from baseline in patients who enter the trial with unfavorable CTCs
- Objective response rate [ Time Frame: 1 year ]The proportion of patients with a CR or PR per PCWG3.
- Time to PSA progression [ Time Frame: 1 year ]
- Radiographic progression free survival [ Time Frame: 1 year ]
- Time to first skeletal-related event (SRE) [ Time Frame: 1 year ]
- Time to first symptomatic skeletal event (SSE) [ Time Frame: 1 year ]
- Time to clinical progression [ Time Frame: 1 year ]
- Time to initiation of new systemic treatment for prostate cancer [ Time Frame: 1 year ]
- To further evaluate the incidence of Treatment-Emergent Adverse Events (safety and tolerability) [ Time Frame: 1 year ]Adverse Events
- Pharmacokinetic parameters [ Time Frame: 1 year ]Area under the concentration versus time curves (AUC)
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03480646
|Study Director:||Debbie Johnson||Constellation Pharmaceuticals|