The immune checkpoint inhibitor Bavencio (avelumab) — given in combination and/or after platinum-based chemotherapy — is no better than chemotherapy alone at delaying disease progression or death in previously untreated women with advanced ovarian cancer, a Phase 3 trial shows.

Merck KGaA (operating as EMD Serono in the U.S. and Canada) and Pfizer, which are developing Bavencio jointly, have decided to terminate the trial  called JAVELIN Ovarian 100 (NCT02718417). Health authorities have been notified about cessation of the study.

Bavencio is an antibody that binds to the PD-L1 molecule, produced by cancer cells to prevent the immune system from recognizing them. By inhibiting PD-L1, Bavencio exposes the cancer cells, boosting the body’s immune surveillance mechanisms.

In women diagnosed at advanced stages of ovarian cancer, the disease tends to progress despite platinum-based chemotherapy, the current first-line treatment for the condition. Thus, researchers investigated if Bavencio could improve the effectiveness of chemotherapy and help extend the time patients lived without signs of disease worsening.

JAVELIN Ovarian 100 tested Bavencio in two regimens – in combination with first-line chemotherapy, or as a maintenance treatment after being given in combination with first-line chemotherapy.

The trial included 998 women with locally advanced or metastatic epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer who had not received prior treatments. Participants were randomly assigned chemotherapy – Paraplatin (carboplatin) and Taxol (paclitaxel) – followed by observation; chemotherapy followed by Bavencio maintetance; and chemotherapy plus Bavencio, followed by Bavencio maintenance.

The study’s primary goal was to determine if Bavencio extended the time patients lived without disease worsening. Secondary goals included overall survival, time to subsequent therapy, and safety.

Bavencio showed no new safety concerns, but an interim analysis showed that the trial would not achieve its primary objective, leading the independent Data Monitoring Committee to recommend study termination. Further analyses of the study’s results are now being conducted and will be shared with the scientific community at a later date, the company said.

This is the second ovarian cancer trial in just a couple of months in which Bavencio failed to meet its primary goal. In another Phase 3 trial — JAVELIN Ovarian 200 (NCT02580058) — the treatment, either alone or in combination with pegylated liposomal doxorubicin (PLD), was no better than PLD only at extending patients lives and the time they lived without disease worsening.

Both these trials are part of the JAVELIN clinical development program, which includes nine Phase 3 clinical trials and more than 7,000 patients across more than 15 tumor types, including ovarian cancer, non-small cell lung cancer, renal cell carcinoma, and others.

Pfizer is also conducting a Phase 3 trial in ovarian cancer patients — called JAVELIN Ovarian PARP 100 trial (NCT03642132) — to test a combination of Bavencio plus the PARP inhibitor Talzenna (talazoparib) as a maintenance treatment after surgery and chemotherapy. The trial is enrolling participants across 101 clinical sites in the U.S., Australia, Europe, and Asia.