116TiP An umbrella trial (RECHALLENGE) to evaluate the safety and preliminary efficacy of combination or sequential immunotherapy in advanced solid tumor patients after disease progression in clinical trials

GroupB Pembrolizumab.The primary endpoints were overall survival (OS) and progression-free survival (PFS), with adverse events (AEs) as secondary endpoints.A pvalue of <0.05 was considered significant.Results: From August 2019 to July 2024, we identified 30 pts.Of those, 53% were in GroupA and 47% in GroupB.Most had transitional cell carcinoma, with 77% from the lower urinary tract and 47% having lymph node-only disease.The median number of PBC cycles was 6, with 40% ineligible for cisplatin.After a median follow-up of 19.9 months (mo) for GroupA and 18.7 mo for GroupB, the mOS was 25 mo and 29.5 mo, respectively (p0.52) and the mPFS of immunotherapy was 14 mo and 8 mo, respectively (p0.51).The median time from the end of PBC and the start of Pembrolizumab was 4.1 mo, with a median treatment duration of 7.6 mo for GroupA and 3.5 mo for GroupB.At the time of data analysis, 40% (n12) of pts were alive and 33% (n10) on treatment, with 40% still receiving Avelumab, and 50% and 10% on subsequent therapies after Avelumab and Pembrolizumab, respectively.In both groups 50% of pts have a neutrophil-to-lymphocyte ratio (NLR) 3 at baseline of PBC.NLR ratio negatively correlates with OS (p0.099) and PFS (p0.047).Both treatments were well tolerated, with Grade 3 AEs in 1 pt on Avelumab and 3 on Pembrolizumab, and no Grade 4 AEs reported.Conclusions: Group A and Group B showed no statistically significant differences in OS and PFS.Of note, more pts were on Avelumab treatment at the data cutoff.AEs were similar in the two groups.Further investigation and follow-up are warranted to gain definitive conclusions on optimal mUC management in the era of immunotherapy and immunoconjugates.