ClinicalTrials.gov posted results on 2026-08-03 for NCT03869190, a terminated phase 1/2 study of atezolizumab combinations in urothelial carcinoma. The MORPHEUS-UC umbrella trial enrolled 272 participants and reported stage 1 metastatic urothelial carcinoma outcomes across multiple treatment arms.

Background

The study focused on urothelial carcinoma, including bladder cancer, in participants with locally advanced or metastatic disease who had progressed during or after a platinum-containing regimen. The posted record describes a multicenter, open-label, randomized umbrella design built to open new treatment arms and close arms with minimal activity or unacceptable toxicity.

Trial design

MORPHEUS-UC was listed as a PHASE1/PHASE2 trial with several immunotherapy-based combinations centered on atezolizumab, including arms with enfortumab vedotin, niraparib, magrolimab (hu5f9-g4), tiragolumab, and other study drugs named in the record. The posted results include stage 1 metastatic urothelial carcinoma cohorts and report progression-free survival and overall survival after randomization.

Key results

In stage 1 mUC cohorts, median progression-free survival was 6.05 months with atezolizumab control, 4.47 months with atezolizumab + enfortumab vedotin, 2.32 months with atezolizumab + hu5F9-G4, 2.23 months with atezolizumab + niraparib, 3.06 months with atezolizumab + RO7122290, 3.48 months with atezolizumab + SG, 3.14 months with atezolizumab + tiragolumab, and 4.07 months with atezolizumab + TCZ.

Median overall survival was 18.79 months with atezolizumab control, 6.83 months with atezolizumab + enfortumab vedotin, 21.82 months with atezolizumab + hu5F9-G4, and 8.57 months with atezolizumab + niraparib. The posted analyses also listed hazard ratios of 1.39, 1.16, 2.16, 1.16, 1.27, and 1.24, each with 95% confidence intervals reported in the record, including 1.06 to 4.42 for one analysis and 0.57 to 2.34 for another.

What this means

The posted results show that outcomes varied substantially across atezolizumab combination arms in this terminated umbrella study. For clinicians and researchers, the record provides a snapshot of how different immunotherapy-based regimens performed in a platinum-pretreated urothelial carcinoma population, but the terminated status and the posted summary format limit interpretation beyond the reported medians and hazard ratios.

Source

This information is based on ClinicalTrials.gov results posted for NCT03869190 on 2026-08-03. The record is available at clinicaltrials.gov.