Randomized phase II trial investigating whether atezolizumab after chemoradiotherapy (CRT) prolongs survival in limited stage (LS) small cell lung cancer (SCLC).

• DOI: 10.1200/jco.2025.43.17_suppl.lba8005
• Publication Date: 2025-06-04T13:29:44Z
• Authors: Bjorn Henning Gro...; Marianne Aanerud; Daphne W. Dumoulin; Jan Nyman; Tine Schytte; Maria Moksnes Bja...; Kirill Neumann; Georgios Tsakonas; Elisabeth Anna Ka...; Nina Helbekkmo; Seppo W. Langer; Sacha Rothschild; Christina Appenze...; Jos Stigt; Tine McCulloch; Hanne Sorger; Marie Søfteland S...; Kristin Toftaker ...; Trude Camilla Frø...; Tarje Onsøien Hal...
• Keywords: Atezolizumab; Chemoradiotherapy

LBA8005 Background: A majority of patients with LS SCLC relapse after potentially curative CRT and better treatment is needed. Immunotherapy prolongs survival in extensive stage non-small cell lung cancer. We investigated whether atezolizumab (“atezo”) SCLC. Methods: Patients PS 0-2 non-progression (PD) platinum/etoposide chemotherapy concurrent twice-daily thoracic radiotherapy (TRT) 45 Gy/30 or 60 Gy/40 fractions were randomized 1:1 to observation atezo 1200 mg Q3W for 1 year, until PD unacceptable toxicity. Atezo commenced 3-7 weeks CRT. Randomization was stratified by performance status (PS) (0-1 vs. 2), CRT-response (stable disease [SD] complete/partial response [CR/PR]) TRT-dose (45 Gy Gy). CRT-responders offered prophylactic cranial irradiation (PCI) 25-30 Gy. PCI allowed start atezo. Primary endpoint: Overall (OS). Secondary endpoints: Response rate (ORR), progression-free (PFS) To detect an increase 2-year from 53% 66% a 1-sided a=0.1 b=0.2, 75 required each group. Results: From July 2018-April 2022, 216 included at 37 European hospitals. 170 (78.7%) (atezo: n=85, observation: n=85). Median age 66 years, 46% women, 92% had 0-1 82% III disease. ORR similar the (95%) (94%) groups. 67% both groups received PCI. number atezo-cycles 8 (range 0-18), 2% 0 cycles 34% completed year treatment. discontinued due (n=18), pneumonitis (n=8), endocrinopathy (n=3), neurotoxicity (n=2), myositis other toxicity (n=9), patients’ wish (n=5), death (n=2) (n=5). time discontinuation 2.8 0.1-12.1) months. After randomization (i.e. post CRT), G3-4 reported group (dyspnea [n=6], fatigue [n=5], endocrinopathies cardiac disorder [n=4], [n=36]), 20% control (anorexia neuropathy dyspnea [n=24]). occurred 4 patients, 2 There 3 treatment-related deaths (neurotoxicity, pneumonia), all 99 events median follow-up 45.1 months (95% CI 40.7-47.3), OS 43.3 25.1-51.2) 38.8 25.8-NR) (HR 1.14, 95% 0.76-1.72; p=0.5). PFS 21.1 9.5-43.4) 15.9 10.6-23.2) 0.88, 0.60-1.28, Conclusion: Atezolizumab therapy did not improve progression free overall Clinical trial information: NCT03540420 .