2600 - Atezolizumab (atezo) vs chemotherapy (chemo) in patients (pts) with platinum-treated locally advanced or metastatic urothelial carcinoma (mUC): a long-term overall survival (OS) and safety update from the Phase III IMvigor211 study

Background

Atezo (anti–PD-L1) is approved for platinum-treated mUC and other indications. Here, we evaluated long-term OS and safety data from IMvigor211, a randomised study evaluating atezo monotherapy vs chemo in platinum-treated mUC (Powles Lancet 2018; primary analysis median follow-up: ≈ 17 mo).

Methods

Pts with disease progression during or following platinum-based chemo were assigned 1:1 to atezo 1200 mg or chemo (vinflunine, paclitaxel or docetaxel per investigator) IV q3w. OS (primary endpoint) and safety were evaluated descriptively in this ad hoc analysis.

Results

As of 8 Nov 2018, median follow-up was 34.3 mo. OS HRs were similar to those from the primary analysis. 24- and 30-mo OS rates were higher with atezo vs chemo in the intent-to-treat (ITT) and PD-L1 populations (Table). In ITT pts, OS HRs with atezo vs taxanes and vinflunine were 0.73 (95% CI: 0.59, 0.90) and 0.90 (95% CI: 0.74, 1.09), respectively. Grade 3-4 treatment-related adverse events (AEs) occurred in 22% of atezo-treated pts and 43% of chemo-treated pts (Grade 5 treatment-related AEs in 1% vs 2%, respectively). AEs leading to treatment discontinuation occurred in 9% of atezo-treated pts and 18% of chemo-treated pts. 11% of atezo-treated patients had a Grade 3-4 AE of special interest (vs 2% with chemo). 29% and 31% of pts in the atezo and chemo arms, respectively, received ≥ 1 subsequent non-protocol therapy; 8% in the chemo arm had non-protocol immunotherapy.Table:

918P OS in IMvigor211 ITT and PD-L1 populations

Data cutoff, 8 Nov 2018. Median follow-up, 34.3 mo (range: 0-42.3). Stratification factors: PD-L1 status on tumour-infiltrating immune cells (IC), chemo type, liver metastases, and number of prognostic risk factors. PD-L1 status on IC evaluated per VENTANA SP142 assay.

Conclusions

In this long-term update from IMvigor211, including 24- and 30-mo OS rates, continued OS benefit in favor of atezo vs chemo was observed in the ITT population and in PD-L1 subgroups. No formal statistical comparisons were performed in this ad hoc analysis. Safety results were consistent with those in the primary analysis.

Clinical trial identification

NCT02302807.

Editorial acknowledgement

Jessica Men, PharmD, of Health Interactions, and funded by F. Hoffmann-La Roche, Ltd.

Legal entity responsible for the study

F. Hoffmann-La Roche, Ltd.

Funding

F. Hoffmann-La Roche, Ltd.

Disclosure

M.S. Van der Heijden: Honoraria (institution), Research grant / Funding (institution): Astellas; Honoraria (institution), Research grant / Funding (institution): BMS; Honoraria (institution), Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Honoraria (institution), Research grant / Funding (institution): AstraZeneca; Honoraria (institution), Travel / Accommodation / Expenses: MSD; Honoraria (institution): Janssen. Y. Loriot: Advisory / Consultancy: Roche. I. Duran: Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Roche; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: MSD; Advisory / Consultancy: Pharmacyclycs; Honoraria (self), Advisory / Consultancy: Janssen; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Ipsen; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self): Astellas. A. Ravaud: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Ipsen; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis. M.M. Retz: Full / Part-time employment: Technical University Munich, Germany. N.J. Vogelzang: Advisory / Consultancy, Shareholder / Stockholder / Stock options: Caris; Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Genentech; Advisory / Consultancy: Esai; Advisory / Consultancy: Tolero; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Bayer; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Sanofi; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Novartis; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Exelixis; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Clovis; Travel / Accommodation / Expenses: SWOG; Travel / Accommodation / Expenses: US Oncology. B. Nelson: Shareholder / Stockholder / Stock options, Full / Part-time employment: Roche/GNE. J. Wang: Advisory / Consultancy, Full / Part-time employment: Roche/GNE. X. Shen: Shareholder / Stockholder / Stock options, Full / Part-time employment: Roche/GNE. T. Powles: Honoraria (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: F. Hoffmann-La Roche; Honoraria (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Honoraria (self), Travel / Accommodation / Expenses: BMS; Honoraria (self), Travel / Accommodation / Expenses: Ipsen; Honoraria (self), Travel / Accommodation / Expenses: Exelixis; Honoraria (self), Travel / Accommodation / Expenses: Merck; Honoraria (self), Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Travel / Accommodation / Expenses: Novartis; Honoraria (self), Travel / Accommodation / Expenses: Incyte; Honoraria (self), Travel / Accommodation / Expenses: Seattle Genetics.