乌鸦传媒

WASHINGTON -- The FDA has rejected the approval application for the sarcoma drug ridaforolimus, according to the drug developer.

In a complete response letter to Merck, FDA officials said additional clinical trials are needed to demonstrate the safety and efficacy of ridaforolimus, a member of the mTOR inhibitor class, posted Tuesday on the company's website.

The decision was not unexpected, since the FDA's Oncologic Drugs Advisory Committee voted 13-1 against approval during a meeting in March.

"Merck remains confident in the potential of ridaforolimus," Eric Rubin, MD, vice president of clinical research oncology, said in the statement. "We will continue to work closely with the FDA to define potential paths forward for this investigational therapy."

Merck is seeking approval of ridaforolimus as maintenance therapy for patients with metastatic soft-tissue or bone sarcomas that have responded or stabilized after chemotherapy. Phase III data submitted to the FDA showed a statistically significant 2-week improvement in median progression-free survival with ridaforolimus versus placebo and a nonsignificant 1.2-month improvement in overall survival.

Half the patients in the ridaforolimus arm discontinued therapy before the end of the trial because of adverse events, including stomatitis, which affected 82% of patients, and rash in 38%.

According to the statement, Merck will continue to work with FDA and regulatory agencies in other countries to win approval of ridaforolimus as maintenance therapy for sarcoma patients who benefited from chemotherapy.