Adenosine Receptor Antagonist Combination Therapy for Metastatic Castrate Resistant Prostate Cancer

Official Title

A Phase 1b/2, Open-Label, Randomized Platform Study Evaluating the Efficacy and Safety of AB928-Based Treatment Combinations in Patients With Metastatic Castrate Resistant Prostate Cancer

Summary:

This is a Phase 1b/2, open-label, multicentre platform trial to evaluate the antitumour activity and safety of etrumadenant (AB928)-based combination therapy in participants with metastatic castrate resistant prostate cancer (mCRPC).

Trial Description

Primary Outcome:

• Objective response rate (ORR), defined as the composite proportion of participants with a PSA and/or radiographic complete and partial response determined by the investigator according to the Prostate Cancer Working Group 3 (PCWG3) criteria
• Incidence and severity of AEs and serious adverse events (SAEs)

Secondary Outcome:

• Proportion of participants with a PSA response defined as the proportion of participants with a confirmed PSA decrease from baseline of 50% or more based on two consecutive assessments measured 3 to 4 weeks apart
• Proportion of participants with measurable disease at baseline who achieved a best overall response of CR or PR according to the Response Evaluation Criteria in Solid Tumours (RECIST) v1.1
• Percentage of Participants with measurable disease at baseline who achieved a best overall RECIST response of CR, PR, or SD
• Serum/ Plasma Concentration etrumadenant, zimberelimab, and enzalutamide when administered as part of a combination regimen in Stage 1 & 2.
• Serum/Plasma Concentration for etrumadenant and zimberelimab when administered as part of a combination regimen with docetaxel in Stage 1 & 2.
• Serum/Plasma Concentration for etrumadenant and zimberelimab when administered as part of a combination regimen in Stage 1 & 2.
• Serum/Plasma Concentration for etrumadenant, zimberelimab, and AB680 when administered as part of a combination regimen in Stage 1 & 2.
• Serum/Plasma Concentration for etrumadenant and AB680 when administered as part of a combination regimen in Stage 1 & 2.
• Percentage of participants with anti-drug antibodies to zimberelimab

This study has several treatment arms and each treatment arm has 2 stages. During Stage 1 - Etrumadenant plus zimberelimab (AB122) alone, etrumadenant plus zimberelimab with or without a standard of care treatment (enzalutamide or docetaxel), or etrumadenant plus AB680 with or without zimberelimab will be administered to participants with mCRPC. During Stage 2

• Additional participants with mCRPC may receive an etrumadenant-based combination therapy evaluated in Stage 1 or, a standard of care treatment. A pharmacokinetic (PK) Sub-Study (etrumadenant plus zimberelimab) will be conducted separately. Treatment may continue until unacceptable toxicity or progressive disease, or other reasons specified in the protocol.

View this trial on ClinicalTrials.gov