UNISON - nivolumab then ipilimumab + nivolumab in advanced non-clear cell renal cell carcinoma (ANZUP 1602): Part 1—Nivolumab monotherapy.

Abstract

325 Background: Immune checkpoint inhibitors (ICI) are active in many cancers, but people with rare variant, non clear-cell renal cell carcinoma (nccRCC) have been excluded from most clinical trials in RCC. UNISON (NCT03177239) aimed to test 2 hypotheses; the activity of nivolumab in nccRCC (Part 1), and the benefit of adding ipilimumab to nivolumab, in people whose cancers progress on nivolumab (Part 2). Methods: 83 participants (pts) with advanced nccRCC with good (ECOG0/1) performance status, were enrolled including papillary type 1 (17%), papillary type 2 (28%), chromophobe (18%), Xp11 translocation (6%), hereditary leiomyomatosis renal cell carcinoma syndrome-associated renal cell carcinoma (6%), RCC unclassified (10%) and other (15%) histological subtypes. Participants took nivolumab (N) 240mg every two weeks in Part 1 in total. If they experienced progression and remained eligible they could take N (3mg/kg) plus ipilimumab (I; 1mg/kg) every 3 weeks for up to 4 doses (Part 2). Pts with disease control after N or N + I could continue N for up to 1 year. UNISON was powered to distinguish a clinically-relevant improvement in objective tumor response rate (OTRR) from 15% to 30% in people taking N+I in Part 2 in pts whose cancers were refractory to single-agent first-line N. Here we report results of Part 1. Results: Pts experience of N appeared similar to previous reports, with most experiencing mild adverse events. 12 treatment related SAE occurred in 11 patients (13%). 14 pts (17%) experienced treatment delays, or permanent treatment discontinuation (10%). The median time on treatment was 5.1 months. The OTRR was 17% with 3 complete responses and 11 partial responses. The median duration of response was 21 months. Stable disease occurred in 49% of pts and disease progression in 34%. The disease control rate at 6 months was 45% (95% CI: 34%, 56%). The median PFS was 4.0 months (95% CI: 3.6, 7.4). The 6 month progression-free survival (PFS) was 45% (95% CI: 34-55) and the 12 months PFS was 30% (95% CI: 21%, 40%). Conclusions: Pts with nccRCC treated with N experience similar adverse events compared to pts with other cancers. A substantial minority of people with nccRCC derive benefit, but many pts have cancers refractory to anti-PD1, similar to other reports. The activity of I and N in this PD1-refractory population is of considerable interest and will be reported at a later date. Clinical trial information: NCT03177239 .