Pfizer’s drug candidate for advanced renal cell carcinoma (RCC), Torisel, failed to meet the primary endpoint of progression-free survival in the Phase III Intorsect study. The trial compared Torisel and Nexavar in patients whose disease had progressed on or after treatment with the company’s approved drug Sutent.
Although PFS was numerically higher in patients treated with Torisel, the difference was not statistically significant. The secondary endpoint of overall survival showed statistical significance favoring patients in the Nexavar arm. Nexavar is marketed by Bayer HealthCare and Onyx Pharmaceuticals.
Torisel is already approved in the U.S. and other countries as a treatment of advanced RCC; i.e., not for a specific line of treatment. Today’s news will upset Torisel’s uptake in the second-line setting.
In the EU it is indicated as first-line therapy for advanced RCC patients who have at least three of six prognostic risk factors. In a Phase III study, Pfizer reports, Torisel demonstrated median overall survival (OS) in previously untreated patients with poor prognostic risk of 10.9 months compared with 7.3 months for patients treated with interferon-alpha (IFN-α).
Torisel garnered FDA support in May 2007 for advanced RCC based on a study that showed use of the drug improved OS and PFS. The FDA nod followed the December 2005 sanction of Nexavar, which showed a delay in progression of disease. In January 2006, Pfizer’s Sutent received accelerated approval based on durable response rate, or tumor size reduction, and was later demonstrated to delay tumor progression. Torisel is an intravenously administered mammalian target of rapamycin (mTOR) inhibitor, while Sutent and Nexavar are oral multikinase inhibitors.