Pfizer has unveiled data from a late-stage trial which shows that its kidney cancer treatment Torisel failed to improve progression-free survival when compared to Bayer's rival drug Nexavar.

The US giant has reported topline results from a Phase III study of Torisel (temsirolimus) as second-line treatment in advanced renal cell carcinoma in patients whose disease had progressed on or after therapy with Pfizer's own Sutent (sunitinib). They reveal that Torisel did not meet the primary endpoint of prolonging PFS when compared to Nexavar (sorafenib), while the secondary endpoint, overall survival, showed statistical significance in favour of the Bayer drug.

Pfizer added that adverse events in the study were consistent with the known safety profiles for both drugs. Full efficacy and safety data will be presented at an upcoming major medical congress.

Despite the disappointing data, Mace Rothenberg, head of clinical development and medical affairs at Pfizer's oncology unit, said "this trial advances our knowledge about Torisel in RCC". He added that it "remains an important drug for treatment of advanced kidney cancer based on its pivotal study in first-line patients with poor prognostic risk".

That study demonstrated median overall survival in previously-untreated patients of 10.9 months in patients with advanced RCC with poor prognostic risk, compared with 7.3 months for interferon-alpha. Torisel is approved in the USA and other countries for the treatment of advanced RCC and in the European Union for the first-line treatment of patients with advanced RCC who have at least three of six prognostic risk factors.