A phase II study of rebeccamycin analog (NSC-655649) in metastatic renal cell cancer

Objective: Rebeccamycin analog (NSC-655649) is an antibiotic with antitumor properties demonstrated in preclinical and phase I studies. We conducted a phase II trial to evaluate the efficacy and toxicity of this agent in patients with advanced renal cell cancer (RCC). Methods: Eligible patients had histologically or cytologically confirmed diagnosis of RCC that was either locally advanced unresectable, locally recurrent, or metastatic. Patients had to have measurable disease, no prior chemotherapy, life expectancy of greater than 12 weeks, an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, adequate-organ function, and be ≥18 years old. Patients were treated with NSC-655649 at a dose of 165 mg/m² daily i.v. over 30-60 min for 5 days. Treatment was repeated every 21 days. Response was assessed every two courses. Results: Twenty-four patients were enrolled. There were sixteen males and eight females with a median age of 60.5 years (range 42-76). Nineteen were Caucasians, seventeen had prior nephrectomy, and thirteen had prior immunotherapy. The major toxicity was myelosuppression with grade 3 and 4 neutropenia in 38% of patients and anemia in 33% of patients. There were two partial responses (2/24, 8%) and 11 patients (46%) achieved stable disease (SD). The 6-month progression-free rate for patients with SD was 30%. Of the seventeen patients with progressive disease at registration, one had a PR and eight had SD. The overall median survival time for all 24 patients was 10.0 months (90% CI = 5.2, 17.4 months). The 12-month survival rate was 39%, with 90% CI = (0.21, 0.58). Nine patients are still alive with survival times ranging from 3.8 to 24.2 months, at a median follow-up time of 11.9 months. Conclusion: Rebeccamycin analog (NSC-655649) is well tolerated and has modest antitumor activity in patients with advanced RCC.