Clinical Trial: IMbassador250: A Study of Atezolizumab (Anti-PD-L1 Antibody) in Combination With Enzalutamide in Participants With Metastatic Castration-Resistant Prostrate Cancer (mCRPC) After Failure of an Androgen Synthesis Inhibitor And Failure of, Ineligibility For, or Refusal of a Taxane Regimen

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: A Phase III, Multicenter, Randomized Study of Atezolizumab (Anti-PD-L1 Antibody) in Combination With Enzalutamide Versus Enzalutamide Alone in Patients With Metastatic Castration-Resistant Prostate Ca

Brief Summary: This Phase III, multicenter, randomized, open-label study will evaluate the safety and efficacy of atezolizumab in combination with enzalutamide compared with enzalutamide alone in participants with mCRPC after failure of an androgen synthesis inhibitor (e.g., abiraterone) and failure of, ineligibility for, or refusal of a taxane regimen. Participants will receive treatment until investigator-assessed confirmed radiographic disease progression per Prostate Cancer Working Group 3 (PCWG3) criteria or unacceptable toxicity.

Detailed Summary:
Sponsor: Hoffmann-La Roche

Current Primary Outcome: Overall surivival (OS) [ Time Frame: Baseline until death ( up to approximately 42 months) ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Percentage of Participants who Survived at Month 12 and 24 [ Time Frame: Months 12, 24 ]
  • Time to Cancer-Related Pain Progression, as Assessed Using Modified Brief Pain Inventory (BPI) [ Time Frame: Baseline until disease progression (up to approximately 42 months) ]
  • Time to First Symptomatic Skeletal Event (SSE) [ Time Frame: Baseline up to 42 months ]
  • Radiographic Progression-Free Survival (rPFS), as Assessed by the Investigator and Adapted From the PCWG3 Criteria [ Time Frame: Baseline until disease progression or death (assessed at baseline then every 9 weeks for first 27 weeks thereafter every 12 weeks until confirmed radiographic disease progression, death, loss to follow-up, up to approximately 42 months) ]
  • Percentage of Participants Who are Radiographic Progression-Free at Month 6 and 12 [ Time Frame: Months 6, 12 ]
  • Immune-Modified rPFS, as Assessed by the Investigator [ Time Frame: Baseline until disease progression or death (assessed at baseline then every 9 weeks for first 27 weeks thereafter every 12 weeks until confirmed radiographic disease progression, death, loss to follow-up, up to approximately 42 months) ]
  • Percentage of Participants With Greater Than (>) 50% Decrease in Prostate-Specific Antigen (PSA) From Baseline [ Time Frame: Baseline up to 42 months (assessed at Screening then prior to study treatment on Day 1 of every cycle [cycle length: 21 days], until confirmed radiographic disease progression, up to 42 months) ]
  • Time to PSA Progression [ Time Frame: Baseline up to 42 months (assessed at Screening then prior to study treatment on Day 1 of every cycle (cycle length: 21 days), until confirmed radiographic disease progression, up to 42 months) ]
  • Percentage of Participant With Objective Response, as Determined by the Investigator Through use of PCWG3 Criteria and Immune Modified Response Evaluation Criteria in Solid Tumors (mRECIST) Criteria [ Time Frame: Baseline until disease progression or death (assessed at baseline then every 9 weeks for first 27 weeks thereafter every 12 weeks until confirmed radiographic disease progression, death, loss to follow-up, up to approximately 42 months) ]
  • Percentage of Participants With Adverse Events [ Time Frame: Baseline up to 42 month ]
  • Minimum Observed Serum Concentration (Cmin) of Atezolizumab [ Time Frame: predose (0 hours[h]) on Day 1 Cycle 2, 3, 4, 8, 12, 16 (Cycle length: 21 days); at atezolizumab discontinuation visit (30 days after last dose); and 120 days after last dose of atezolizumab up to 42 months ]
  • Maximum Observed Serum Concentration (Cmax) of Atezolizumab [ Time Frame: predose (0 h) on Day 1 Cycle 1, 2, 3, 4, 8, 12, 16 (Cycle length: 21 days); 0.5h postdose (infusion:60 minutes) on Day 1 of Cycle 1; at atezolizumab discontinuation visit (30 days after last dose); 120 days after last dose of Atezolizumab up to 42 months ]
  • Plasma Concentration of Enzalutamide [ Time Frame: predose (0 h) and 1 h postdose on Day 1 Cycle 1 and 3 (Cycle length: 21 days); pre-dose (-1 h) on Day 1 Cycle 8; up to 42 months ]
  • Plasma Concentration of N-desmethyl Enzalutamide [ Time Frame: predose (0 h) and 1 h postdose on Day 1 Cycle 1 and 3 (Cycle length: 21 days); pre-dose (-1 h) on Day 1 Cycle 8; up to 42 months ]
  • Percentage of Participants With Anti-therapeutic Antibody (ATAs) to Atezolizumab [ Time Frame: predose (0 h) on Day 1 Cycle 1, 2, 3, 4, 8, 12, 16 (Cycle length: 21 days); at atezolizumab discontinuation visit (30 days after last dose); 120 days after last dose of atezolizumab; up to 42 months ]
  • Percentage of Participants who Required Initiation or Increase in Opiate Analgesic use for Cancer Pain [ Time Frame: Baseline up to 42 months ]
  • Time to Initiation or Increased Opiate Analgesic Use [ Time Frame: Baseline up to 42 months ]


Original Secondary Outcome: Same as current

Information By: Hoffmann-La Roche

Dates:
Date Received: January 9, 2017
Date Started: January 11, 2017
Date Completion: July 9, 2022
Last Updated: May 15, 2017
Last Verified: May 2017