Atezolizumab (atezo) + platinum/gemcitabine (plt/gem) vs placebo + plt/gem for first-line (1L) treatment (tx) of locally advanced or metastatic urothelial carcinoma (mUC): Final OS from the randomized Phase 3 IMvigor130 study.
Matt D. Galsky, Jóse Ángel Arranz Arija, Maria De Santis, Ian D. Davis, Aristotelis Bamias, Eiji Kikuchi, Xavier García del Muro, Se Hoon Park, Ugo De Giorgi, B. Yа. Alekseev, Marina Mencinger, Kouji Izumi, Javier Puente, Jian‐Ri Li, Peter H. O’Donnell, Sandrine Bernhard, Chooi Peng Lee, Fabiola Bene‐Tchaleu, Sanjeev Mariathasan, Enrique Grande
Abstract
LBA440 Background: The IMvigor130 primary analysis demonstrated statistically significant PFS benefit with 1L atezo + plt/gem (Arm A) vs placebo + plt/gem (Arm C) in pts with mUC (Galsky Lancet 2020). Interim data showed improved OS with Arm A vs C but did not cross the pre-specified threshold for significance (Galsky Lancet 2020; Galsky AACR 2021). In exploratory analyses, OS improved when atezo was combined with cisplatin (cis) vs carboplatin (carbo) regardless of PD-L1 status. Here, we report final OS data from Arms A and C. Methods: Pts were randomly assigned 1:1:1 to Arm A, B (atezo alone) or C. Arm A and C pts received cis or carbo per investigator (INV) choice. Co-primary endpoints were PFS per INV RECIST 1.1 and OS (Arm A vs C), and OS (Arm B vs C), tested hierarchically. Safety, ORR and DOR, disease control rate (DCR; confirmed CR, PR or [SD ≥ 6 mo]) and pre-specified exploratory OS data are also reported. Results: As of data cutoff Aug 31, 2022 (49 mo since last pt randomly assigned), in ITT pts, OS benefit was not statistically significant; in the cis subgroup, HR was 0.76 (95% CI 0.57, 1.01; Table). In ITT pts, DCR was 65% (290/447) in Arm A and 60% (239/397) in Arm C. 81% of safety-evaluable pts (370/454) in Arm A and 80% (312/389) in Arm C had a Gr 3/4 tx-related AE (TRAE). Gr 5 TRAEs occurred in 9 pts (2%) in Arm A and 4 (1%) in Arm C; Gr 3/4 AEs of special interest were seen in 41 pts (9%) in Arm A and 17 (4%) in Arm C. Conclusions: In this final analysis, improved OS with atezo + plt/gem vs placebo + plt/gem did not reach statistical significance in ITT pts with mUC. As seen with prior exploratory data, improved OS with atezo + plt/gem was greater when pts received cis vs carbo. No new safety signals were seen. Clinical trial information: NCT02807636 . [Table: see text]