Randomised Phase II study comparing alternating cycles of sunitinib and everolimus vs standard sequential administration in first-line metastatic renal carcinoma (SUNRISES study).

Objective: To investigate the efficacy of alternating cycles of sunitinib and everolimus vs standard sequential treatment of sunitinib followed by everolimus in first-line metastatic renal cell carcinoma (mRCC), as alternating blockade of vascular endothelial growth factor receptor (VEGFR) and mammalian target of rapamycin (mTOR) pathways could potentially prevent the occurrence of resistance to anti-VEGFR therapy in mRCC.

Patients And Methods: SUNRISES, a randomised open-label Phase II study, investigated the efficacy of alternating cycles of sunitinib and everolimus vs standard sequential treatment of sunitinib followed by everolimus upon progression. Treatment-naïve patients with clear-cell mRCC were included. Alternating treatment consisted on 12 weeks of sunitinib, followed by 12 weeks of everolimus. The primary endpoint was the progression-free survival (PFS) rate at 1 year. The secondary endpoints included the median PFS, overall survival (OS), response rate, and safety.

Results: Accrual was low due to the advent of new-generation therapies, and the study was stopped prematurely. Only 41 patients out of the planned 102 patients were accrued, and randomised in a 2:1 ratio (15 patients to the control arm, 26 to the experimental arm). In all, 60.9% of patients had performance status (PS) 0 and 39% PS 1; 63% had a favourable prognostic risk profile, while 36% were intermediate risk. The primary endpoint was not met. The 1-year PFS rate was 49.7% (experimental arm) vs 84.62% (control arm; P = 0.11). There was a trend towards fewer Grade ≥3 adverse events with the alternating approach (50% vs 73.3%; P = 0.14). The median OS was similar in both treatment arms. The other secondary endpoints favoured the control arm.

Conclusions: The study failed to show any benefit of alternating cycles of sunitinib and everolimus in patients with mRCC. The alternating approach using an mTOR inhibitor does not seem to prevent the occurrence of resistance to VEGFR blockade.