UC San Diego

Background

We performed a phase I modified 3 + 3 dose escalation study to evaluate the safety and activity of bevacizumab plus gemcitabine and nab-paclitaxel in patients with advanced solid tumours.

Methods

Patients were given fixed dose gemcitabine plus increasing doses of nab-paclitaxel and bevacizumab. Toxicity, response, and association with VEGF polymorphism was analysed.

Results

The study enrolled 110 patients who had undergone a median of 3 prior lines of therapy. The median age was 60 years (range, 17-85 years), and 55 patients (50%) had gemcitabine-refractory disease. We observed 3 dose-limiting toxicities during dose escalation and 3 DLTs in expansion cohorts. Dose escalation to 150 mg/m² nab-paclitaxel and 15 mg/kg bevacizumab with 1000 mg/m² of gemcitabine was well tolerated with no MTD. One patient with gemcitabine-refractory peritoneal papillary carcinoma had a complete response, 13 patients (13%) had partial responses, and 54 patients (52%) had stable disease ≥12 weeks. Exploratory VEGF single nucleotide polymorphism (SNP) analysis was performed on 13 patients.

Conclusions

The combination of gemcitabine, nab-paclitaxel, and bevacizumab is safe, well-tolerated, and has activity in advanced malignancies, including gemcitabine-refractory tumours. Based on this study, the recommended phase 2 dose is gemcitabine 1000 mg/m², nab-paclitaxel 125 mg/m², and bevacizumab 15 mg/kg. VEGF polymorphism data should be evaluated in future bevacizumab-based trials.