{"entity":{"id":"impower133","kind":"trial","name":"IMpower133","aka":[],"tldr":"IMpower133 was the first trial in decades to lengthen survival in extensive-stage small-cell lung cancer, by adding immunotherapy to chemotherapy.","summary":"Median OS 12.3 vs 10.3 months (HR 0.70); PFS 5.2 vs 4.3 months. Established chemo-immunotherapy as first-line standard (FDA March 2019). The IMbrella A extension reported the first five-year survival data for chemo-immunotherapy in ES-SCLC, with a small tail of long-term survivors in the atezolizumab arm. Benefit was independent of PD-L1 and TMB.","status":"positive","asOf":"2026-09-07","links":[{"label":"ClinicalTrials.gov NCT02763579","url":"https://clinicaltrials.gov/study/NCT02763579"},{"label":"Five-year OS (IMbrella A)","url":"https://pubmed.ncbi.nlm.nih.gov/39306923/"}],"tags":[],"related":[],"cancers":["sclc","extensive-stage-sclc"],"sections":[],"technologies":["checkpoint-inhibitor"],"targets":[],"drugs":["atezolizumab","platinum-etoposide"],"companies":["roche-genentech"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":["anne-chiang"],"bottlenecks":[],"keyPapers":["paper-impower133-n-engl-j-med-2018"],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT02763579","phase":"3","setting":"First-line extensive-stage SCLC: carboplatin-etoposide + atezolizumab vs carboplatin-etoposide + placebo","sponsor":"Roche","result":"OS 12.3 vs 10.3 months, HR 0.70.","started":"2016-06-07","startedType":"actual","yearReported":2018,"enrolled":403,"enrolledBasis":"registry","outcomes":[{"endpoint":"Overall survival","primary":true,"unit":"months","arms":[{"name":"Atezolizumab + CE","n":201,"value":12.3},{"name":"Placebo + CE","n":202,"value":10.3}],"hr":0.7,"ci":[0.54,0.91],"p":"0.007","source":"https://www.nejm.org/doi/full/10.1056/NEJMoa1809064"},{"endpoint":"Progression-free survival","primary":true,"unit":"months","arms":[{"name":"Atezolizumab + CE","value":5.2},{"name":"Placebo + CE","value":4.3}],"hr":0.77,"ci":[0.62,0.96],"source":"https://doi.org/10.1056/NEJMoa1809064"}],"replication":"Replicated by CASPIAN (durvalumab, 2019) and by serplulimab (ASTRUM-005), tislelizumab (RATIONALE-312), adebrelimab and toripalimab trials in China; the class effect is one of the best-replicated in SCLC."},"route":"/trials/impower133/","neighbours":{"cancer":[{"id":"extensive-stage-sclc","kind":"cancer","name":"Extensive-stage small-cell lung cancer","route":"/cancers/extensive-stage-sclc/"},{"id":"lung-cancer","kind":"cancer","name":"Lung cancer (all types)","route":"/cancers/lung-cancer/"},{"id":"sclc","kind":"cancer","name":"Small-cell lung cancer","route":"/cancers/sclc/"}],"technology":[{"id":"checkpoint-inhibitor","kind":"technology","name":"Immune checkpoint inhibitors","route":"/technologies/checkpoint-inhibitor/"}],"drug":[{"id":"atezolizumab","kind":"drug","name":"Atezolizumab","route":"/drugs/atezolizumab/"},{"id":"platinum-etoposide","kind":"drug","name":"Platinum + etoposide (EP / CE)","route":"/drugs/platinum-etoposide/"}],"company":[{"id":"roche-genentech","kind":"company","name":"Roche / Genentech","route":"/companies/roche-genentech/"}],"person":[{"id":"anne-chiang","kind":"person","name":"Anne C. Chiang","route":"/people/anne-chiang/"}],"paper":[{"id":"paper-paz-ares-caspian-durvalumab-es-sclc-lancet-2019","kind":"paper","name":"Durvalumab plus platinum-etoposide versus platinum-etoposide in first-line treatment of extensive-stage small-cell lung cancer (CASPIAN)","route":"/key-papers/paper-paz-ares-caspian-durvalumab-es-sclc-lancet-2019/"},{"id":"paper-impower133-n-engl-j-med-2018","kind":"paper","name":"First-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer","route":"/key-papers/paper-impower133-n-engl-j-med-2018/"}],"trial":[{"id":"capstone-1","kind":"trial","name":"CAPSTONE-1","route":"/trials/capstone-1/"},{"id":"crest-thoracic-rt","kind":"trial","name":"CREST: consolidation thoracic radiotherapy in extensive-stage small-cell lung cancer","route":"/trials/crest-thoracic-rt/"}]}}