Thread by @StephenVLiu

#ESMO20 Grateful for the chance to present characterization of long-term #SCLC survivors with atezolizumab and carboplatin/etoposide in IMpower 133. #LCSM @IASLC @OncoAlert

#ESMO20 IMpower 133 was a placebo controlled, double blind, randomized phase III trial for patients with treatment naive ES-SCLC that showed the addition of atezolizumab to 1L carboplatin + etoposide improved PFS and OS, leading to FDA and EMA approval in 2019. #LCSM @OncoAlert

#ESMO20 Using a cutoff of 18 months for long-term survival after a median follow up of 22.9 months, more LTS were seen with atezolizumab (33.5 of patients). #LCSM

#ESMO20 More long term survivors with atezolizumab in all subgroups including patient characteristics of age, sex and PS, and disease characteristics including # of sites, liver/brain mets, high LDH, high sum of longest diameter. #LCSM

#ESMO20 Biomarkers from IMpower 133 included tissue PDL1 expression (Ventana SP263) and blood based #TMB. Neither with utility in patient selection for benefit with atezolizumab (all subgroups had better outcomes with addition of immunotherapy). #LCSM

#ESMO20 Several factors appeared prognostic in the univariate analysis but in the multivariate, only PS, LDH and SLD were confirmed as poor prognostic variables. Impact of atezolizumab on OS more pronounced after adjustment for other covariates, with a significant HR of 0.71.

#ESMO20 Overall, more patients receiving atezolizumab with carboplatin/etoposide achieved long term survival than chemo alone, across patient and disease characteristics, reaffirming the IMpower133 regimen as a standard of care. bTMB and PD-L1 not useful in patient selection

#ESMO20 Thanks to all of the patients who partnered with us on this trial and the many co-investigators and coauthors. @HornLeora @TonyMok9 @AMansfieldMD @marinagarassino @AndresFCardonaZ @MartinReck2