A phase I study of rebeccamycin analog in combination with oxaliplatin in patients with refractory solid tumors.

Rebeccamycin analog (RA) is an antitumor antibiotic with both topoisomerase I and II inhibiting activity. Topoisomerase inhibitors have demonstrated synergy with platinum agents. We performed a phase I trial of combination RA with oxaliplatin in patients with refractory solid tumors. RA was administered as a 1-hour infusion daily on days 1-5 with oxaliplatin administered on day 5. Cycles were repeated every 21 days. A total of 17 patients were enrolled. The MTD for RA was 80 mg/m(2)/d for five days along with oxaliplatin 130 mg/m(2) on day 5. Myelosuppression was a common occurrence but was mild except in one instance. Dose limiting toxicities included atrial fibrillation and hypophosphatemia. There was evidence of antitumor activity including 3 partial responses in patients with esophageal, gallbladder and hepato-cellular carcinoma; 5 additional patients had stable disease. Thus, the combination of RA and oxaliplatin is both tolerable and has evidence of clinical activity, but given the lack of significant activity for single agent RA across a variety of disease sites, it is unlikely to proceed to phase II development.