German drugmaker Bayer AG and the USA’s Onyx Pharmaceuticals were hit with bad news yesterday as they were forced to call time on a Phase III trial assessing the potential of Nexavar in skin cancer.

The companies halted the study after it emerged that it wouldn’t meet the primary endpoint of improved overall survival, and that there was little difference in patients taking the drug alongside chemotherapy and those taking a placebo combination.

Nexavar is already on the market for the treatment of liver and kidney cancer and is pegged to become a blockbuster in 2010, but the companies will understandably be disappointed with the drug’s failure in this indication, particularly as melanoma is considered a difficult tumour to treat.

According to the groups, more 108,000 people worldwide were diagnosed with melanoma and more than 40,000 of them died from the disease in 2007 alone, and there were high hopes that Nexavar, which works by targeting both the tumour cell and tumour vasculature, would offer an effective option for improving patient survival.

Bayer and Onyx say they will now further review the data to determine any potential impact on other ongoing Nexavar melanoma trials, but stress they remain “committed to our broad clinical program to investigate the potential of Nexavar in a wide range of cancers”, and that they intend to build upon its success in the approved indications, according to Dimitris Voliotis, Vice President in Global Clinical Oncology at Bayer HealthCare.