Background: Pts with PS > 1 have a poor prognosis and are often excluded from clinical trials. The single-arm SAUL study (NCT02928406) evaluated atezo in a ‘real-world’ population. Overall, safety and efficacy were consistent with prior trials. However, ECOG PS 2 pts had worse overall survival (OS) but fewer adverse events (AEs) than ECOG PS 0/1 pts [Sternberg, 2019], likely reflecting shorter treatment duration and warranting exploration. Methods: Pts with mUTC received atezo 1200 mg q3w until loss of clinical benefit or unacceptable toxicity. The primary endpoint was safety. Post hoc analyses compared baseline factors, AEs and efficacy in pts with ECOG PS 2 vs 0/1. In this analysis, AE incidences were restricted to the first 45 days of atezo to adjust for differing treatment exposure. Results: None of the baseline factors explored was significantly associated with worse OS or disease control rate (DCR) in ECOG PS 2 pts. However, pts with visceral metastases and ECOG PS 2 had particularly poor outcomes. Safety appeared similar between subgroups. Conclusions: ECOG PS 2 pts have a dismal prognosis. The higher proportion with poor prognostic factors despite similar age in ECOG PS 2 vs 0/1 pts may suggest that poor PS was related to disease rather than comorbidities. Risk/benefit should be considered especially carefully when treating pts with ECOG PS 2 due to high-burden/visceral disease. Clinical trial information: NCT02928406.

^an = 97; ^bn = 873; ^cn = 100; ^dn = 889; ^en = 91; ^fn = 837. ^gCR/PR or stable disease for ≥4 wks

G = grade