LBA93 First results from RAMPART: an international phase III randomised-controlled trial of adjuvant durvalumab monotherapy or combined with tremelimumab for resected primary renal cell carcinoma (RCC) led by MRC CTU at UCL

Background
RAMPART is a randomised trial of immune checkpoint inhibitor therapy for 1 year versus active monitoring after resection of primary renal cell carcinoma.

Methods
We recruited participants (pts) from 80 sites and randomised them in a 3:2:2 ratio between: Arm A, active monitoring; Arm B, 1 year (13 cycles) of durvalumab; or Arm C, 1 year (13 cycles) of durvalumab plus tremelimumab (cycles 1 and 2 only). Recruitment was stopped early for reasons other than efficacy or safety, and the statistical analysis plan was adjusted before any unblinded analyses. The modified plan gives 80% power to detect a true hazard ratio (HR) for disease free survival (DFS) of

Results
Between October 2018 and June 2023, we randomised 790 pts: 340 Arm A, 225 Arm B, 225 Arm C. Baseline characteristics were similar in Arms C and A: median age (range) was 60 (22, 83) years, 70% were male, and 84% had clear cell histology. DFS was longer among those assigned durvalumab and tremelimumab (Arm C) than active monitoring (Arm A); DFS at 2 years 84% vs. 78%, HR 0.65, 95% CI 0.45 to 0.93, 1p=0.0094. Pre-specified and pre-powered DFS analysis in 311 higher-risk pts (Table) showed a HR=

Conclusions
Adjuvant therapy with durvalumab and tremelimumab after resection of RCC improved DFS, particularly among those at highest risk of relapse.