Feasibility and prognostic relevance of maintenance after chemoimmunotherapy in extensive-stage small-cell lung cancer: a real-world study

Background In extensive-stage small-cell lung cancer (ES-SCLC), platinum-etoposide (PE) with PD-(L)1 blockade is the first-line standard of care. This study analyzed the feasibility of transition to maintenance immunotherapy in a real-world cohort. Methods We retrospectively analyzed 406 patients with histologically confirmed ES-SCLC receiving first-line chemoimmunotherapy between 2019 and 2025. Tumor responses and dates of progression were verified by investigator review of radiological images according to RECIST. Results Atezolizumab (n = 166) or durvalumab (n = 82) maintenance was possible for 61.1% (248/406; 95% confidence interval [CI], 56.2%–65.9%) of patients, who showed longer PFS (median 6.4 vs. 3.0 months) and OS (17.6 vs. 5.7 months, p<0.001 in a descriptive analysis) than patients not entering maintenance. Main obstacles to maintenance were disease progression and early death, together affecting 27.3% of all patients (n=112). In multivariable logistic regression, liver metastases (odds ratio [OR] 0.625; 95% CI, 0.402–0.972; p=0.037), ECOG PS ≥2 (OR 0.440; 95% CI, 0.199–0.969; p=0.042), and elevated serum lactate dehydrogenase (LDH) at diagnosis (OR 0.450; 95% CI, 0.278–0.728; p=0.001) were independently associated with a lower likelihood of maintenance initiation. The same three parameters together with male sex were also independently associated with shorter OS in the overall cohort (HR 1.43-4.60, p≤0.006). Conclusions Only approximately 60% of patients with ES-SCLC starting chemoimmunotherapy could proceed to immunotherapy maintenance in the real-world setting. Liver metastases, elevated LDH, and poor ECOG PS are readily available baseline factors independently associated with the feasibility of maintenance and OS, which may help prioritize high-risk patients for novel intensified strategies.