147P - Activity of single-agent PD-1/PD-L1 inhibitors in 1st-line (1L) “platinum-ineligible” patients (pts) with metastatic urothelial cancer (mUC) in real-life clinical practice

Background

Data from real-practice in more than 4,000 pts diagnosed of mUC in the US show that only 33.2% are receiving systemic 1L platinum-based ( approaches (Morgans et al. ESMO 2021). Surprisingly, in the same series up to 45.9% of these pts were treated with PD-1/PD-L1 inhibitors or non-platinum chemotherapy. Recently, a consensus-based definition was proposed to define “platinum-ineligible” mUC population i(Gupta et al. ASCO 2022). Since this “platinum-ineligible” population is becoming more and more relevant in daily practice, we collected our experience with single agent PD-1/PD-L1 inhibitors in 1L mUC and compared the efficacy between “cis-ineligible” vs “platinum-ineligible” populations.

Methods

This is a multicenter and retrospective study to compare the outcomes of mUC pts treated with single agent PD-1/PD-L1 inhibitors in the 1L setting at 3 academic institutions in Spain. Pts were treated and evaluated according to institutional local guidelines. Pts characteristics, activity and treatment-related toxicities were gathered. A Cox regression analysis was conducted to explore the association of baseline variables.

Results

Between 2019-2021, 39 pts with a mean age of 75.4 y.o. received either atezolizumab (N=24, 61.5%) or pembrolizumab (N=15, 38.5%) as 1L mUC treatment. Liver mets were observed in 7 (17.9%) pts. Fifteen (38.5%) pts met Gupta’s criteria, being Cr Cl < 30 ml/min (30.8%) and ECOG PS 2 and Cr Cl < 60 ml/min (53.8%) the most frequent reasons to be qualified as “platinum-ineligible”. Median follow-up time was 14.4 months (m). Overall response rate (ORR) in the entire population was 53.8%. ORR was 58.3% and 46.7% in cis- and platinum-ineligible population respectively. Median PFS was 11.6 and 10.2m for cis- and -platinum ineligible pts (HR 0.99; 95%CI 0.41-2.38). No statistical differences in overall survival were seen. Only 1 (2.6%) pt had a grade ≥3 immune-related adverse event (nephritis).

Conclusions

Efficacy and safety of single-agent PD-1/PD-L1 inhibitors appears similar in the cis- and platinum-ineligible 1L mUC pts. Prospective randomized data and biomarkers are needed to evaluate the robustness of its use in the clinic.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Grupo Centro de Tumores Genitourinarios.

Funding

Roche.

Disclosure

J. Molina Cerrillo: Financial Interests, Personal, Advisory Board: IPSEN, Janssen, BMS, Eisai; Financial Interests, Personal, Invited Speaker: Pfizer, AAA, Roche, Janssen; Financial Interests, Personal, Expert Testimony: Astellas; Financial Interests, Personal, Research Grant: Ipsen, Pfizer. A. Pinto Marin: Financial Interests, Personal, Advisory Board: Pfizer, BMS, Janssen, Astellas, Ipsen, Clovis, Bayer, Sanofi, Roche, Merck, MSD, Astra Zeneca; Financial Interests, Personal, Invited Speaker: Pfizer, BMS, Janssen, Astellas, Bayer, Pierre Fabre, Roche; Financial Interests, Personal, Research Grant: Pfizer, BMS; Financial Interests, Personal and Institutional, Invited Speaker: Roche, Pfizer, Pfizer, Exelixis, Eisai, Bayer, Bayer, Janssen, Novartis, BMS, Clovis, Aveo, MSD. T. Alonso Gordoa: Financial Interests, Personal, Advisory Board: IPSEN, Sanofi, Bayer, EISAI, Novartis Advanced Accelerator Applications, Lilly; Financial Interests, Personal, Invited Speaker: Pfizer, Roche, Janssen-Cilag; Financial Interests, Institutional, Advisory Board: Bristol Myers Squibb; Non-Financial Interests, Personal, Project Lead: Pfizer, IPSEN. J.A. Arranz Arija: Financial Interests, Personal, Advisory Board: Astellas, BMS, Merck, Pfizer, Bayer, MSD, EISAI; Financial Interests, Personal, Invited Speaker: Astellas; Financial Interests, Institutional, Invited Speaker, SOGUG: BMS. E. Grande Pulido: Financial Interests, Personal, Invited Speaker: Adacap, Astra Zeneca, Bristol Myers Squibb, Eisai, Eusa Pharma, IPSEN, Janssen, Lilly, Merck KGa, Pfizer, Roche; Financial Interests, Personal, Advisory Board: Astellas, Bayer, MSD, Novartis, Sanofi-Genzyme; Financial Interests, Institutional, Advisory Board: Caris Life Sciences, ONCODNA (Biosequence); Financial Interests, Institutional, Research Grant, Independent research grant: Astellas, Astra Zeneca, Lexicon, MTEM/Threshold, Nanostring Technologies, Pfizer, Roche, Merck; Financial Interests, Institutional, Invited Speaker, Independent research grant: IPSEN; Non-Financial Interests, Personal, Other, AD BOARD member: ENETS. All other authors have declared no conflicts of interest.