1541P Real-world data of atezolizumab plus carboplatin-etoposide for patients with extensive stage SCLC: The UK experience

Abstract

The addition of atezolizumab to carboplatin/etoposide (A-CE) for patients with extensive stage SCLC (ES-SCLC) has been recently established as standard first-line treatment on the basis of the IMPOWER-133 trial. Unfortunately, efficacy and safety data of this combination in the real-world setting is lacking. We retrospectively evaluated consecutive patients with ES-SCLC treated with A-CE between January 2020 and September 2021 in eight centres in the UK. Clinical and pathological data was collected and analysed. A total of 192 patients were included. Baseline clinical characteristics are summarized in the table. One hundred forty seven (77,8%) patients received four cycles of A-CE; median number of doses of atezolizumab was 7 (range 1-20). Fifty-two (27%) patients also received prophylactic cranial irradiation and sixty-one (31,7%) consolidation thoracic radiotherapy. Seventy-six (39,6%) patients received at least one subsequent treatment. At a median follow-up of 15 months, median progression-free survival (PFS) and overall survival (OS) were 5,31 and 8,85 months, respectively. Overall response rate was 69,7%. The OS rates at 12 months and 18 months were 38,25% and 20,36%, respectively. Treatment-related adverse events led to discontinuation of treatment in 32 patients (16,7%).Table: 1541PMedian age – years (range)66 (35-83)Sex – no. (%)MaleFemale83 (43,2)109 (56,8)Smoking status NeverCurrentFormerUnknown9 (4,7)50 (26,0)116 (60,4)17 (8,8)ECOG performance status score – no. (%)012330 (17)140 (73)21 (11)1 (0,5)Stage (TNM 8th edition) – no. (%)IIIIV14 (7,3)178 (93)Concomitant autoimmune disease – no. (%) Brain metastasis – no. (%)12 (6) 29 (15) Open table in a new tab Data from our series show comparable PFS but inferior OS than those reported in the trial. Known negative prognostic factors were more common in our cohort of patients at baseline and may have determined a shorter OS. Real-world data in this setting could help to optimise clinical management of these patients.