A phase II trial of bevacizumab plus everolimus for patients with refractory metastatic colorectal cancer

Abstract

Purpose. For patients with metastatic colorectal cancer (mCRC), no standard therapy exists after progression on 5-fluorouracil, oxaliplatin, irinotecan, bevacizumab, and cetuximab or panitumumab. Preclinical data demonstrated that combined vascular endothelial growth factor and mammalian target of rapamycin inhibition has greater antiangiogenic and antitumor activity than either monotherapy. A phase I study of bevacizumab plus everolimus demonstrated that the combination is safe; activity was seen in several patients with refractory mCRC. Methods. Fifty patients with refractory mCRC were enrolled and received bevacizumab at 10 mg/kg every 2 weeks and everolimus at 10 mg orally daily. Results. Of the 50 patients enrolled, the median age was 56 years and the median number of prior regimens was four. Forty-seven patients (96%) had prior bevacizumab exposure and 42 patients (84%) had documented progression on prior bevacizumab-based therapy. Forty-nine patients were evaluable for response; eight patients had minor responses (16%) and an additional 15 patients (30%) had stable disease (SD). No complete or partial responses were seen. The median progressionfree survival interval was 2.3 months; however, 26% of patients achieved prolonged SD for >6 months, and three patients (6%) were on study for >1 year. The median overall survival duration was 8.1 months. The most common grade 1-2 toxicities were mucositis (68%) and hyperlipidemia (64%). Clinically significant grade >3 toxicities included hypertension (14%), fistula/abscess/ perforation (8%), mucositis (6%), and hemorrhage (2%). Conclusions. Bevacizumab plus everolimus is generally tolerable but may have risks related to mucosal damage and/or wound healing. Bevacizumab plus everolimus appears to have modest activity in refractory mCRC in patients.