A late-stage trial of Pfizer's Torisel has shown that adding the drug to Roche's Avastin does not significantly extend progression-free survival (PFS) in patients with advanced kidney cancer.

The US drug giant said Friday that the Phase III INTORACT trial - which assessed a combination of Torisel (temsirolimus) and Avastin (bevacizumab) compared with Avastin plus interferon-alfa-2a - failed to meet its primary endpoint of superiority in extending PFS in patients with advanced renal cell carcinoma (RCC).

Avastin and interferon-alfa-2a are approved for the treatment for advanced RCC, as is Pfizer's mTOR inhibitor Torisel (but as a standalone therapy), and it was hoped that adding the two treatments together would be of benefit to patients, which now seems unlikely.

Further details of the findings were not given at this point, but Mace Rothenberg, senior vice president of clinical development and medical affairs for Pfizer’s Oncology Business Unit, said the company would carry out additional analyses "to help us understand this result".

He also stressed that the study result "does not change the safety and efficacy relationship of single-agent Torisel for advanced RCC patients with a poor prognostic risk profile”.

Other efficacy endpoints and safety data for the combination treatments are also currently being analysed and will be shared at an upcoming major medical congress, the company said.