Atezolizumab for locally advanced or metastatic urothelial carcinoma of the urinary tract: Analysis of UK patients treated in the international SAUL study


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Robert Huddart1,Jason F Lester2,Guy Faust3,Neil McPhail4,Hajer Lassidi5,Simon Fear6,Thomas Powles7
1Institute of Cancer Research,2Velindre Cancer Centre, Cardiff (current affiliation: Swansea Bay University Health Board, Singleton Hospital, Swansea),3Leicester Royal Infirmary NHS Trust, Leicester,4Raigmore Hospital, Inverness,5Roche Products Ltd, Welwyn Garden City,6F Hoffmann-La Roche Ltd, Basel,7Barts Cancer Institute, Experimental Cancer Medicine Centre, Queen Mary University of London, St Bartholomew’s Hospital, London

Abstract

Background

Atezolizumab, which targets PD-L1, is approved as treatment for locally advanced/metastatic urothelial carcinoma based on results from the IMvigor210 (NCT02108652) and IMvigor211 (NCT02302807) phase II/III trials. The single-arm international SAUL study (NCT02928406; n=1004) in a broader population demonstrated median overall survival (OS) of 8.7 months and a safety profile consistent with previous atezolizumab trials. We analysed outcomes in 38 patients with urothelial carcinoma treated in UK centres in SAUL.

Method

Patients with pretreated locally advanced/metastatic urothelial carcinoma, including those with renal impairment, ECOG performance status 2 (PS2), stable controlled autoimmune disease or corticosteroid treatment, received atezolizumab 1200mg every 3 weeks until loss of clinical benefit or unacceptable toxicity. The primary endpoint was safety; secondary endpoints included OS, progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR).

Results

Median age was 70 years, 11% had ECOG PS2, 45% had never smoked, 92% were platinum pretreated, 47% had received no chemotherapy for metastatic disease and 39% would have been ineligible for the pivotal IMvigor211 trial. At the data cut-off (16-Sep-2018, 16 months’ median follow-up), treatment was ongoing in 8 patients (21%). Median treatment duration was 2.9 (range 0–18) months. The most common adverse events (AEs) were fatigue (21%), urinary tract infection (18%) and nausea (18%). Grade ≥3 AEs occurred in 55%, considered treatment related in 8 patients (21%; 6 grade 3, 1 grade 4, 1 grade 5). AEs led to treatment discontinuation in only 2 patients (5%). Median OS was 7.5 (95% CI 2.6–14.2) months, 1-year OS rate was 34% (18–50%), median PFS was 2.1 (2.1–4.4) months, ORR was 11% (3–25%) and DCR was 40% (24–57%).

Conclusion

Atezolizumab demonstrated good tolerability in 38 UK patients with urothelial carcinoma treated in SAUL. Efficacy results are consistent with previous atezolizumab results in this setting.