Wyeth is facing a delay in getting Torisel onto the market after US regulators said they need more time to look at clinical data relating to the new kidney cancer treatment.

The firm noted that the US Food and Drug Administration has extended its review of the New Drug Application for Torisel (temsirolimus) for advanced renal cell carcinoma, which was originally submitted on October 5 last year and was granted priority review status. As part of the review, Wyeth recently submitted additional information on tumour evaluation, as requested by the FDA, which means that the action date for the NDA has been extended by three months to July, “to allow the agency time to complete a full review of these analyses”.

Wyeth did not seem overly concerned by the delay and the company’s research president Robert Ruffolo said: "We are encouraged by the review process so far, and, with the submission of these analyses, we remain optimistic about the prospects for strengthening the product labelling for launch in the third quarter of 2007." The pivotal study of Torisel showed that the drug significantly increased overall survival by 49% in patients with advanced renal cell carcinoma compared with those treated with interferon-alpha.

Torisel 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. If given the green light, it will come up against two recently-approved drugs for renal cell carcinoma, namely Pfizer's Sutent (sunitinib) and Bayer/Onyx' Nexavar (sorafenib) and Wyeth will be hoping that Torisel will reduce its reliance on the blockbuster antidepressant Effexor (venlafaxine) which had sales of $3.7 billion last year.

Puerto Rico plant inspection completed

Meantime, Wyeth noted that the FDA has completed its reinspection of the firm’s Guayama, Puerto Rico facility which was criticised by the agency over manufacturing problems in May 2006. The company said that it will respond to FDA's questions by the middle of this month, and hopes that the agency "will be able to determine in the near future that the warning letter issues have been satisfactorily resolved." The Guayama facility also underwent a current Good Manufacturing Practices inspection by the European Medicines Agency in March and this was “concluded successfully with no critical or major observations” and Wyeth received a positive evaluation of the site’s compliance status.

The manufacturing problem is a serious one for the firm because the FDA has told Wyeth that it must sort out quality control at the plants if it is to receive approval for its new antidepressant Pristiq (desvenlafaxine), the follow-up to Effexor.