Intermittent Sunitinib in Previously Untreated Metastatic Renal Cell Carcinoma
Intermittent sunitinib dosing appears feasible in patients with untreated metastatic renal cell carcinoma, according to data from a phase II study published by Moshe C. Ornstein, MD, MA, of the Cleveland Clinic Taussig Cancer Institute, and colleagues, in the Journal of Clinical Oncology. Sunitinib is standard front-line therapy in this population, but chronic dosing necessitates balancing toxicity with clinical benefit.
Thirty-seven treatment-naive patients were treated with four cycles of sunitinib at 50 mg/d for 4 weeks, followed by 2 weeks without treatment. Patients with ≥ 10% reduction in the tumor burden after four cycles had sunitinib withheld, with restaging scans performed every two cycles. Sunitinib was reinitiated for two cycles in patients with a ≥ 10% increase in tumor burden and held again after a ≥ 10% reduction in the tumor.
Of the 37 patients, 20 (54%) entered the intermittent-dosing phase. At data cutoff, 16 had restarted therapy after an initial break, 3 had not reached the tumor growth threshold to restart therapy, and 1 withdrew from the study. To date, median progression-free survival is 22.4 months among all patients, compared with 37.6 months in the intermittent-dosing group.
“Periodic extended sunitinib treatment breaks are feasible, and clinical efficacy does not seem to be compromised,” the investigators reported.