Sunitinib Rechallenge in Metastatic Renal Cell Carcinoma Patients

BACKGROUND: Sunitinib was a standard initial therapy in metastatic renal cell carcinoma (mRCC). Given the fact that many patients progressed through many available therapies and antitumor activity had been demonstrated with sequential vascular endothelial growth factor-targeting approaches, a retrospective review was performed of the experience of rechallenge with sunitinib in sunitinib-refractory mRCC. METHODS: mRCC patients who received sunitinib therapy after disease progression on prior sunitinib and other therapy were retrospectively identified. Patient characteristics, toxicity, clinical outcome, Response Evaluation Criteria in Solid Tumors (RECIST) objective response rate, and progression-free survival (PFS) were recorded. RESULTS: Twenty-three mRCC patients who were rechallenged with sunitinib were identified. Upon rechallenge, 5 patients (22%) achieved an objective partial response. The median PFS with initial treatment was 13.7 months and 7.2 months with rechallenge. Patients with >6-month interval between sunitinib treatments had a longer PFS with rechallenge than patients who started the rechallenge within 6 months (median PFS, 16.5 vs 6.0 months; P = .03). There was no significant difference in outcome to sunitinib rechallenge based on number or mechanism of intervening treatments. Substantial new toxicity or significantly increased severity of prior toxicity was not seen during rechallenge in this cohort. CONCLUSIONS: Sunitinib rechallenge had potential benefits and was tolerated in select metastatic RCC patients. Additional prospective investigation was warranted. Cancer 2010;116:5400-6. (C) 2010 American Cancer Society.