Pfizer and Merck KGaA have announced that they will be terminating the Phase III JAVELIN Ovarian 100 study of Bavencio (avelumab), as the data did not support the study's initial hypothesis.

A planned interim analysis showed that the drug would not achieve superiority in the pre-specified primary endpoint of progression-free survival (PFS), where the primary endpoint was PFS in favour of one or both of the Bavencio-based regimens over chemotherapy alone.

The study involved 988 previously untreated patients with locally advanced or metastatic epithelial ovarian, fallopian tube or primary peritoneal cancer. The JAVELIN Ovarian PARP 100 study and earlier phase studies investigating the drug in various combinations are still ongoing.

A spokesperson for the companies said: "While detailed analyses of the data are ongoing, no new safety signals were observed, and [the anti-PD-L1 antibody's safety profile in the trial] appears consistent with that observed in the overall JAVELIN clinical development programme."

They also confirmed that detailed results from the study will "be shared with the scientific community.”

Every year, more than 295,000 women are diagnosed with ovarian cancer worldwide, and it unfortunately tends to be advanced when it is diagnosed, as it often has few to no symptoms at the early stages, making it difficult to detect.

The five-year survival rate ranges from approximately 30% to 50%, but for those with metastatic disease (where it has spread to other body parts), it drops to less than 20%