Bristol-Myers Squibb’s melanoma drug Yervoy has failed a late-stage trial assessing overall survival in prostate cancer patients but the firm is still encouraged by the data.

The Phase III trial compared Yervoy (ipilimumab) to placebo following radiation in patients with advanced metastatic castration-resistant prostate cancer (mCRPC) who have received prior treatment with docetaxel. The 799-patient study’s primary endpoint of overall survival did not reach statistical significance (11.2 months versus 10 months for placebo) but anti-tumour activity “was observed across some efficacy endpoints, including progression free-survival”, B-MS noted. More data will be presented at the European Cancer Congress in Amsterdam at the end of the month.

Winald Gerritsen of the Radboud University Nijmegen Medical Centre in the Netherlands, noted that although the study did not meet its primary endpoint, there is “a suggestion of greater activity in those with less advanced CRPC”. He claimed that “these results offer important insights for ongoing and future studies of Yervoy in prostate cancer”, including an ongoing second large trial in patients with less advanced disease.

Yervoy was approved in 2011 for unresectable or metastatic melanoma and is a big earner for B-MS. As well as prostate cancer, it is also being studied in Phase III trials in adjuvant melanoma and non-small cell lung cancer.