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Thomas Flaig, MD


Anti–PD-L1 Therapy With PARP Inhibitor Focus of Phase II Trial in Urothelial Cancer

By: Vanessa A. Carter, BS
Posted: Tuesday, March 22, 2022

Jonathan E. Rosenberg, MD, of Memorial Sloan Kettering Cancer Center, New York, and colleagues evaluated the use of the anti–PD-L1 agent durvalumab combined with olaparib—a PARP inhibitor—versus placebo in the first-line treatment of platinum-ineligible patients with unresectable, stage IV urothelial carcinoma. Although the phase II BAYOU trial did not meet its primary endpoint (progression-free survival), the results of preplanned secondary analyses suggest a potential role for PARP inhibition in individuals harboring homologous recombination repair (HRR) gene mutations. These findings were presented during the 2022 American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium (Abstract 437).

This study enrolled 154 adults with unresectable, stage IV urothelial carcinoma who were ineligible for platinum-based chemotherapy and did not undergo prior systemic therapy. Participants were randomly assigned to receive durvalumab plus either olaparib (n = 78) or placebo (n = 76) and were stratified according to centrally determined HRR gene mutation status.

Approximately 20% of patients had an HRR gene mutation, and 17%, 42%, and 40% had an Eastern Cooperative Oncology Group performance status of 0, 1, or 2, respectively. Among the intent-to-treat population, the median progression-free survival did not appear to be significantly different between patients on anti–PD-L1 therapy plus olaparib and placebo.

In the subgroup of patients with HRR gene mutations, however, the median progression-free survival was longer among individuals treated with the PARP inhibitor versus placebo (5.6 vs. 1.8 months). Additionally, the median overall survival was similar among patients given olaparib and placebo in the intent-to-treat population (10.2 vs. 10.7 months).

Although no new safety signals were observed, grade 3 or 4 treatment-related adverse events affected twice as many patients given olaparib than those given placebo (18% vs. 9%). Of note, one death due to anemia occurred in the placebo group.

Disclosure: For full disclosures of the study authors, visit

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