Bayer and partner Onyx Pharmaceuticals have suffered a blow after their oncology agent Nexavar did not prolong life for patients in lung cancer in a late-stage study.

The companies said that the final analysis of the Phase III NExUS trial evaluating Nexavar (sorafenib) tablets in patients with advanced non-squamous non-small cell lung cancer showed that the study did not meet its primary endpoint of improving overall survival in the first-line setting. The trial evaluated Nexavar versus placebo in combination with two chemotherapies, gemcitabine and cisplatin.

In 2008, based on the results seen in a previous Nexavar first-line NSCLC Phase III trial, the NExUS study protocol was amended to stop enrolling and treating squamous cell carcinoma patients as a higher mortality in the latter group had been observed. Bayer and Onyx say they will further review the findings of this analysis “to determine what, if any, impact these data might have on other ongoing clinical trials evaluating the safety and efficacy of Nexavar”. The drug is currently marketed for liver and kidney cancers.

Dimitris Voliotis, an oncology chief at Bayer HealthCare, admitted the firms are disappointed with these results, but “we are confident in our clinical trial programme exploring Nexavar's potential in a variety of tumor types, including lung cancer”. He added that based on “encouraging data from a recently-presented prospective biomarker trial and Phase II signal-generating lung cancer studies, we believe it's critical to continue our evaluation of Nexavar in combination with targeted agents and as a monotherapy in later lines of treatment in lung cancer patients”.

Nexavar is being evaluated by the companies and individual investigators in a variety of treatment settings for patients with NSCLC, including a Phase III monotherapy study in the third- and fourth-line setting and Phase II studies in combination with other therapies in the second-line setting. Previously, Bayer forecast peak sales of around 750 million euros from Nexavar in the NSCLC indication alone.