Giant drugmaker Pfizer Inc. announced Thursday that it stopped a Phase III clinical trial testing its kidney cancer drug Sutent in patients with advanced breast cancer because it appeared to be ineffective in slowing the disease.

 

Sutent, also known as a sunitinib, was approved in 2006 for both gastrointestinal stromal tumor (gist) after disease progression or intolerance to imatinibb mesylate and advanced / metastatic renal cell carcinoma (RCC). Pfizer acquired the drug with the 2003 purchase of Pharmacia Corp. for about $58 billion. Pharmacia had gotten the drug with its own purchase of the biotechnology company Sugen Inc.

 

Pfizer said in a statement that the drug wouldn’t be able to demonstrate “a statistically significant improvement” in survival rates without the tumor growing, when compared to capecitabine, also known as Xeloda, marketed by Roche.

 

“We are disappointed with these results given the previous findings that suggested sunitinib may provide benefit for patients with this difficult-to-treat. In ongoing studies, we remain committed to evaluating sunitinib in advanced breast cancer and are continuing to study sunitinib in different populations and with different regimens,” Dr. Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs for Pfizer’s Oncology Business Unit.

 

However, Pfizer is still analyzing Sutent to treat advanced breast cancer in three late-stage and two mid-stage trials. The drug had sales of $847 million last year, including $254 million in the United States.