Pfizer (PFE) said on Friday that a late-stage study of its renal cell cancer drug failed to meet expectations when combined with Roche’s Avastin.

Pfizer's drug Torisel is already approved as a single agent for the treatment of advanced renal cell cancer, which Pfizer said kills some 13,000 Americans each year.

The company had hoped to show that combining Torisel with Avastin would be even more effective in extending progression-free survival than Avastin combined with interferon-alfa-2a.

However, the experimental cancer treatment did not meet its primary endpoint of extending progression free survival in the study population, Pfizer said.

The New York-based pharmaceutical giant said efficacy endpoints and safety data for the combination treatment is being analyzed and will be presented at an upcoming major medical conference.

“This trial advances our knowledge about the role and limitations of combining targeted therapies in the treatment of advanced RCC,” Dr. Mace Rothenberg, senior vice president of clinical development and medical affairs for Pfizer’s Oncology Business Unit, said in a statement.

Additional analysis will be performed to help us understand this result, Pfizer said.

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