Tesaro's shares are routed on late-stage cancer drug data

Tesaro touted positive results for the primary endpoints laid out for the late-stage program it had underway for its top cancer drug prospect rolapitant, but investors soured on the drug after it failed to score secondary goals and drove the biotech's shares down by a hefty 22% this morning.

Waltham, MA-based Tesaro ($TSRO) unveiled top-line results for two Phase III studies of rolapitant, noting that the drug achieved statistical significance for preventing chemo-induced nausea and vomiting (CINV). But while "a greater proportion of patients treated with rolapitant in this trial achieved a (complete response) in the acute and overall phases and experienced no significant nausea compared to the control arm…statistical significance was not met for these secondary endpoints." Ditto for the second Phase III study.

A third Phase III rolapitant study is still underway, leaving Tesaro on track for a mid-2014 NDA. But investors clearly didn't care for the lay of the land this morning. Nevertheless, Tesaro stuck with the sunny view.

"Despite the availability of preventative therapies and established treatment guidelines for CINV, a significant number of cancer patients still suffer from the debilitating side effects of delayed nausea and vomiting," Mary Lynne Hedley, president of Tesaro, said in a statement. "We are enthusiastic about the potential for this product candidate, with a profile that may include an extended half life, convenient, single-dose oral and intravenous formulations and a lack of CYP3A4-mediated drug interactions."

- here's the release