Pfizer Inc. today announced the discontinuation of one of its Phase 3 studies based on statistical assessment for futility: the SUN 1107 Phase 3 study of Sutent(R) (sunitinib malate) in advanced breast cancer. SUN 1107 evaluated single-agent sunitinib versus single-agent capecitabine for the treatment of a broad range of patients with advanced breast cancer after failure of standard treatment. An independent Data Monitoring Committee (DMC) found that even if the trial had been allowed to continue, treatment with single-agent sunitinib would be unable to demonstrate a statistically significant improvement in the primary endpoint of progression-free survival (PFS) compared to single-agent capecitabine in the study population. Data from this trial are currently being analyzed. “We are disappointed with these results given the previous findings that suggested sunitinib may provide benefit for patients with this difficult-to-treat cancer,” said Dr. Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs for Pfizer’s Oncology Business Unit. “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.” Pfizer has notified clinical trial investigators involved in the study and regulatory agencies of these findings. The Company encourages investigators to determine the best course of action for their individual patients. The company is continuing to evaluate sunitinib as a single-agent and in combination with standard-of-care chemotherapy in specific patient populations with advanced breast cancer through three additional Phase 3 and two Phase 2 trials. Sunitinib is currently approved for both gastrointestinal stromal tumor (GIST) after disease progression on or intolerance to imatinib mesylate, and advanced / metastatic renal cell carcinoma (RCC) based on efficacy and safety data from large, randomized Phase 3 clinical trials. Sunitinib has played an important role in reshaping the treatment landscape for these two difficult-to-treat cancers. To date, more than 58,000 patients globally have been treated with sunitinib in the clinical setting and in clinical trials.
