113P - Clinical outcomes of avelumab and pembrolizumab in advanced urothelial cancer: An observational multicenter retro-prospective study on patients undergoing treatment in clinical practice (AVePEm study)

Background

Patients (pts) with metastatic urothelial carcinoma (mUC) who do not experience disease progression after 4-6 cycles of first-line platinum-based chemotherapy (PBC) may benefit from immunotherapy as maintenance treatment with Avelumab, or receive Pembrolizumab as a second-line.

Methods

AVePEm is a multicenter, observational, retrospective study involving pts with mUC who did not progress after 4 cycles of PBC: GroupA received Avelumab and GroupB Pembrolizumab. The primary endpoints were overall survival (OS) and progression-free survival (PFS), with adverse events (AEs) as secondary endpoints. A p-value 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 (p=0.52) and the mPFS of immunotherapy was 14 mo and 8 mo, respectively (p=0.51). 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% (n=12) of pts were alive and 33% (n=10) 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 (p=0.099) and PFS (p=0.047). 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.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

D. Pastorelli: Financial Interests, Personal, Advisory Role: MSD Oncology, Amgen, Ipsen, Novartis, Pfizer, Astellas, Leo Pharma, GSK, AbbVie, Bayer. M. Milella: Financial Interests, Personal, Advisory Role: AstraZeneca, MSD Oncology, Janssen Oncology; Financial Interests, Personal, Research Funding: Roche; Financial Interests, Personal, Funding: Ipsen, Servier, Viatris; Financial Interests, Personal, Other: Novartis, Oncosil. All other authors have declared no conflicts of interest.