Phase I clinical trial of bendamustine and bevacizumab for patients with advanced cancer

Bendamustine, a cytotoxic alkylating agent, has shown promising results in solid tumors. An investigator-initiated phase I clinical trial of the anti-vascular endothelial growth factor agent bevacizumab and bendamustine was conducted in patients with advanced cancer, because the 2 drugs have different mechanisms of antitumor activity and nonoverlapping toxicity. Patients were treated with escalating doses of intravenous bendamustine (70, 80, 90, and 100 mg/m²; days 1 and 2) and intravenous bevacizumab (10 mg/kg; days 1 and 15). A conventional "3 + 3" study design was used. Forty-two patients were treated: 23 women and 19 men. The median age was 60 years. Patients had received a median of 4 prior therapies (range, 1-10). The most common cancer types were colorectal (n=9), head and neck (n= 8), non-small cell lung (n=6), and breast (n=5). Overall, 117 cycles were administered (median per patient, 2; range, 1-8). No dose-limiting toxicities were noted during the escalation phase. Therefore, the highest dose (level 4) of bendamustine (100 mg/m²) was used in the expansion phase. The most common toxicities were fatigue (n=22), nausea (n=14), anorexia (n=9), and thrombocytopenia (n=7). Of 38 patients who were evaluable for response, 23 (61%) had stable disease, including 2 (5.2%) who had stable disease for 6 months or more (1 with adenoid cystic carcinoma and 1 with non-small cell lung cancer). This regimen of bendamustine (100 mg/m²) and bevacizumab (10 mg/kg) was well tolerated and yielded disease stabilization in selected heavily pretreated patients with advanced cancer.