Wyeth Pharmaceuticals, a division of Wyeth, announced that the US FDA has granted a new "fast track" designation for temsirolimus (CCI-779), an investigational mTOR kinase inhibitor, in the first-line treatment of poor-prognosis patients with advanced renal cell carcinoma (RCC). Previously, in March 2002, the FDA had designated temsirolimus for fast track status in the treatment of renal cell carcinoma after failure of initial therapy.

In granting this fast track designation to temsirolimus, the FDA noted the facts- Advanced or metastatic RCC is a serious and life-threatening condition with few therapeutic options; Metastatic RCC is generally regarded as an incurable disease that is highly resistant to systemic therapy;
Chemotherapeutic and radio-therapeutic approaches have not significantly improved outcomes in patients with metastatic RCC, and
Current available therapy for patients with metastatic RCC is immunotherapy with cytokines, which provides a tumour response (shrinkage) in some patients. In a phase II study, a 7 per cent overall response rate of temsirolimus was observed in advanced RCC patients.

"After the phase II study we decided to change the development strategy to pursue first-line therapy in advanced RCC patients. Currently a phase III study comparing temsirolimus alone, interferon alpha alone and temsirolimus with interferon alpha is underway to determine the clinical benefit of temsirolimus as first-line therapy with survival as the primary endpoint," says Gary L Stiles, Chief Medical Officer, executive vice president, Wyeth Pharmaceuticals. "This new fast track designation for temsirolimus may be an important step towards developing a potential new treatment for patients with advanced renal cell carcinoma," he added.

The FDA's fast track programme is designed to facilitate development and expedite review of new drugs or biologicals that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs. However, fast track designation does not guarantee approval or expedited approval of any application for the product.

Phase III trials are underway using temsirolimus, an mTOR inhibitor, for several cancers including renal cell carcinoma and advanced metastatic breast cancer. The trials are investigating whether temsirolimus has the potential to provide improved survival rates for advanced cases of these cancers. In addition, based on the mTOR mechanism of action, temsirolimus is in clinical trials to investigate its therapeutic utility in other diseases such as mantle cell lymphoma, rheumatoid arthritis and multiple sclerosis.

"Temsirolimus provides a glimpse of the strength and innovation in Wyeth's oncology pipeline, which holds the potential for new treatments for a variety of cancers," says Robert R Ruffolo, Jr., president, Wyeth Research and senior vice president, Wyeth.