Abstract
BACKGROUND: The Fast Real-time Assessment of Combination Therapies in Immuno-ONcology study in patients with aRCC (FRACTION-RCC) was designed to assess new immuno-oncology (IO) combinations in patients with advanced renal cell carcinoma (aRCC). We present results in IO-naive patients treated with nivolumab (NIVO) + relatlimab (RELA) or NIVO + ipilimumab (IPI) in track 1. METHODS: The open-label, randomised, phase II FRACTION-RCC trial enrolled patients with aRCC from 32 hospitals and cancer centres across six countries. Patients were enrolled in track 1 (IO-naive) or track 2 (IO-experienced). IO-naive patients were stratified by previous tyrosine kinase inhibitor therapy and randomised to NIVO (240 mg) + RELA (80 mg) intravenously once every 2 weeks or NIVO (3 mg/kg) + IPI (1 mg/kg) intravenously once every 3 weeks for four doses, followed by NIVO (480 mg) once every 4 weeks, each up to ∼2 years. The primary endpoints were objective response by investigator (RECIST version 1.1), duration of response (DOR), and progression-free survival (PFS) rate at 24 weeks. Safety was a secondary endpoint; biomarker analyses were exploratory. RESULTS: FRACTION-RCC enrolled patients between 2 February 2017 and 23 January 2020. In track 1, 30 patients each were treated with NIVO + RELA or NIVO + IPI (clinical database lock, 1 November 2021). With NIVO + RELA [median follow-up, 48.6 months; interquartile range (IQR) 46.9-51.7 months], objective response was 30% [95% confidence interval (CI) 15% to 49%], with 33 weeks (95% CI 16-53 weeks) median DOR. The PFS rate at 24 weeks was 43% (95% CI 25% to 60%). With NIVO + IPI (median follow-up, 48.7 months; IQR 47.1-52.0 months), the objective response was 20% (95% CI 8% to 39%), with the median DOR not reached (95% CI 33 weeks-not estimable). The PFS rate at 24 weeks was 49% (95% CI 29% to 66%). Higher baseline lymphocyte activation gene 3 (LAG-3) and programmed death-ligand 1 (PD-L1) expression levels were detected among track 1 NIVO + RELA responders. Grade 3-4 treatment-related adverse events were reported in 4/30 (13%) patients treated with NIVO + RELA and 10/30 (33%) patients treated with NIVO + IPI. No deaths were attributed to study treatments. CONCLUSIONS: Results showed antitumour activity and manageable safety with NIVO + RELA. Findings also support NIVO + IPI as an effective combination regimen in IO-naive patients with aRCC.