Combination of antiangiogenic therapy and cytotoxic chemotherapy for sarcomatoid renal cell carcinoma.

4512 Background: Numerous treatment options exist for metastatic renal cell carcinoma (mRCC), but optimal treatment for patients (pts) with sarcomatoid features remains undefined. Sarcomatoid differentiation is a particularly unfavorable prognostic feature in mRCC. Cytotoxic chemotherapy has modest activity, with a response rate of 16% for doxorubicin plus gemcitabine (Gem). Retrospective data has suggested a response rate of 10% for antiangiogenic therapy. We prospectively studied the combination of antiangiogenic therapy, sunitinib (Su), with Gem chemotherapy in this mRCC subpopulation. Methods: Pts with mRCC and sarcomatoid differentiation were enrolled in a phase 2 clinical trial at 3 institutions. Treatment consisted of 21-day cycles of Su, 37.5 mg on a 2 weeks on/1 week off schedule, along with Gem 1000 mg/m2 on days 1 and 8. The primary endpoint was radiographic response rate (RR) by RECIST. Secondary endpoints included time to disease progression (TTP), safety, and overall survival (OS). Results: ...