Clinical activity of sunitinib rechallenge in metastatic renal cell carcinoma-Results of the REchallenge with SUnitinib in MEtastatic RCC (RESUME) Study

Aim: To assess the efficacy and tolerability of sunitinib rechallenge in the third-line or later setting in patients with metastatic renal cell carcinoma (mRCC).

Patients and methods: This observational study comprised 61 mRCC patients at 19 centres in France who received sunitinib rechallenge between January 2006 and May 2013. Patients received first-line sunitinib, ≥1 different targeted therapies, and then sunitinib rechallenge. Patient/disease characteristics, tolerability, treatment modalities, and outcomes of therapeutic lines were recorded. The primary end-point was progression-free survival (PFS) in sunitinib rechallenge.

Results: Analyses included 52 patients; median age was 59 years, 75% were male, and 98% had clear-cell mRCC and prior nephrectomy. At sunitinib rechallenge versus first-line, patients had poorer performance (Karnofsky performance status 90-100: 30% versus 81%) and Memorial Sloan Kettering Cancer Centre prognostic risk (poor risk: 18% versus 3%). Overall, 20%, 65%, 12%, and 4% received sunitinib rechallenge as third-, fourth-, fifth-, and sixth-line therapy, respectively, at 14.6 months (median) after stopping initial treatment. With first-line sunitinib and rechallenge, median PFS was 18.4 and 7.9 months, respectively; objective response rate was 54% and 15%. Two of eight rechallenge responders had not achieved first-line response. Median overall survival was 55.9 months. The sunitinib rechallenge safety profile was as expected, with no new adverse events reported.

Conclusions: Sunitinib rechallenge is a feasible treatment option with potential clinical benefit for mRCC patients. Disease progression with first-line sunitinib may not be associated with complete or irreversible resistance to therapy.