Wyeth says that the US Food and Drug Administration has granted priority review status to a New Drug Application for the company's cancer treatment Torisel.

Torisel (temsirolimus), which has been filed for the treatment of advanced renal cell carcinoma, comes from a drug class known as mTOR (mammalian target of rapamycin) inhibitors and is the first agent of its type to be filed for approval in a cancer indication. The drug has already received fast-track and orphan drug status in the USA.

Wyeth's registration dossier for the treatment contains interim data from a three-arm, Phase II trial of 626 patients who had received no prior systemic therapy. The results showed that Torisel significantly increased overall survival by 49% in patients with advanced renal cell carcinoma compared with those treated with interferon-alpha.

The American Cancer Society estimates that there will have been almost 39,000 new cases of renal cell carcinoma in the USA by the end of 2006, and about 13,000 sufferers will die from it. If approved, Torisel will come up against two recently-approved drugs for renal cell carcinoma, namely Pfizer's Sutent (sunitinib) and Bayer/Onyx' Nexavar (sorafenib).