Abstract 736P
Background
In mRCC radical surgery of metastases in selected pts has shown improved survival rates. Previously we reported that sorafenib did not improve relapse free survival over observation (obs) after surgery in a randomized prospective trial . Here we present the updated follow up data of the RESORT trial (NCT01444807).
Methods
RESORT was a multicenter, randomized, phase 2 trial that enrolled pts with clear-cell mRCC undergoing radical excision of the primary tumor and metastases (≤3 lesions). Within 12 weeks from surgery, pts were randomized (1:1) to obs or SOR 400 mg BID for 52 weeks and stratified according time from nephrectomy to metastases (≤ or >12 months [mos]), site (lung vs others) and number of lesions (single vs multiple). Recurrence-free survival (RFS), the time from randomization to disease relapse or death, was the primary endpoint. Overall survival and safety the secondary. RFS curves were estimated with the Kaplan-Meier method and compared with the log-rank test. Cox model was used to estimate the hazard ratio (HR) SOR vs obs.
Results
76 pts were screened and 69 randomized between November 2012 and November 2017. We performed the analyses on 68 pts(32 in SOR and 36 in obs arm)because one of them never started therapy. 81% in SOR and 80% in obs arm had a single metastasis. Lung was the main involved site in 31% and 24%, respectively. At a median follow up time of 42 mos (interquartile range 31-58) the median RFS was 35 mos in obs vs 21 mos in SOR arm. In obs arm the RFS probability was 57% (95% CI 42-76%) at 24 mos and 44% (95% CI 30-65%) at 48 mos; 2 pts died at 4 and 14 mos. In SOR arm the RFS probability was 50% (95% CI 34-71%) at 24 mos and 32% (95% CI 18-57%) at 48 mos (p=0.342; HR 1.35; 95% CI 0.72-2.54).17/36 pts(47%) and 12/32(37.5%) are still disease free in the two arms, respectively. Relapses developed mostly in lung, lymphnodes, brain, bone, liver and pancreas, irrespective of the site of previous metastasectomy.
Conclusions
SOR after radical metastasectomy in mRCC has not shown to prolong RFS. Anyway, surgery of metastases should be considered in well-selected pts to potentially improve survival. Accordingly, in our study most pts (47% in obs arm) are relapse-free at a median follow-up of 42 mos.
Clinical trial identification
NCT01444807.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Bayer.
Disclosure
G. Procopio: Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Bayer; Advisory/Consultancy: BMS; Advisory/Consultancy: Ipsen; Advisory/Consultancy: Jansen; Advisory/Consultancy: MSD; Advisory/Consultancy: Novartis; Advisory/Consultancy: Pfizer. All other authors have declared no conflicts of interest.