Immunotherapy (IO) with antiPD1/PD-L1 antibodies is a standard treatment for advanced non-small cell lung cancer (NSCLC), with higher benefits with PDL1+. However, optimal duration of treatment remains unknown. In some pivotal trials, IO was given until disease progression or toxicity, and others limited treatment to two years. This study aimed to assess if continuation therapy with antiPD1/PDL1 therapies in advanced NSCLC past two years is superior to shorter treatment.
Retrospective study of patients treated with antiPD1/PDL-1 therapies for advanced NSCLC in a single institution. Two groups were performed: patients treated past two years (group1); patients who stopped treatment after two years or before due to toxicity (group2). To evaluate survival, Cox regression analysis and Kaplan Meier curves with log-rank were performed.
27 patients fulfilled inclusion criteria: 7 patients (group1) and 20 patients (group2). Toxicities by which immunotherapy was suspended were pneumonitis (n=6), cutaneous (n=4), gastrointestinal (n=3), hypophysis (n=2), hepatitis and keratitis (n=1). Patients’ characteristics: average age was 69, 96% were smokers or former smoker and 81.5% adenocarcinomas; 12 patients received immunotherapy as first and 13 as second-line. 3 complete response, 13 partial responses and 11 stable disease were achieved. Overall survival (OS) was 21.61 months (Group1) vs 11.78 months (Group 2), p=0.19. Progression-free survival (PFS) was 15.23 months (Group1) vs 11.86 months (Group2), p=0.206. Differences in OS were observed when the analysis was performed comparing treatment duration >1 vs ≤1year (OS: 21.96 vs 10.90 months, p=0.029;); not if compared >18 vs 18months (OS: 22.9 vs 11.97 months, p=0.091). Two patients from group 2 were retreated with immunotherapy at disease progression, colitis and pneumonitis reappeared requiring definitive suspension.
In our series, a favorable trend is observed in OS and PFS in patients who were treated beyond two years; differences were statistically significant for patients treated >1 year. Retrospective nature and small sample of patients condition our results and limit their interpretation.
Legal entity responsible for the study
A.V. Pellicer Boigues.
Has not received any funding.
All authors have declared no conflicts of interest.