Trial results for the Phase 2 study (NCT04383743) investigating pembrolizumab and combination chemotherapy for muscle-invasive bladder cancer were posted on ClinicalTrials.gov on 2025-09-18. The study reported a pathologic complete response rate in 9 participants and an estimated 2-year event-free survival of 64%.
Background
This pilot study evaluated pembrolizumab, an immunotherapy, combined with chemotherapy for specific types of muscle-invasive bladder cancer with unusual appearances (variants). Pembrolizumab is a monoclonal antibody designed to help the body's immune system attack cancer cells. The chemotherapy regimen included drugs such as methotrexate, doxorubicin, and cisplatin, which work to stop the growth of tumor cells.
Trial design
The study (NCT04383743) was a Phase 2 pilot trial that enrolled 17 participants. It investigated pembrolizumab and combination chemotherapy before surgery for the treatment of Stage II Bladder Cancer AJCC v8, Stage IIIA Bladder Cancer AJCC v8, and Muscle Invasive Bladder Carcinoma. The interventions included pembrolizumab, cisplatin, doxorubicin, methotrexate, and pegfilgrastim.
Key results
The trial reported several key outcomes for the treatment group (Pembrolizumab, aMVAC):
- The pathologic complete response rate was observed in 9 participants.
- The frequency of any adverse event related to study therapy, according to Common Terminology Criteria for Adverse Events Version 5.0 (CTCAE v5.0), was reported in 17 participants.
- The frequency of Grade 3 or greater adverse events related to study therapy was observed in 8 participants.
- The estimated 2-year event-free survival (EFS) was 64% (95% Confidence Interval).
- 14 participants were able to undergo radical cystectomy within 10 weeks from completion of study therapy.
What this means
The results from this Phase 2 pilot study suggest that pembrolizumab combined with chemotherapy may offer a beneficial treatment approach for patients with muscle-invasive bladder cancer, particularly concerning the observed pathologic complete response rate and 2-year event-free survival. The safety profile indicates that all participants experienced some adverse events, with a notable proportion experiencing Grade 3 or higher events, which is important for clinical consideration. The ability of most participants to proceed with radical cystectomy within the specified timeframe also provides valuable insight into the feasibility of this neoadjuvant regimen.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04383743, titled "Pembrolizumab and Combination Chemotherapy Before Surgery for the Treatment of Muscle-Invasive Bladder Cancer," were posted on 2025-09-18 on clinicaltrials.gov.