Comparison of different maintenance regimens following first-line immunochemotherapy for advanced non-small cell lung cancer

Background: Immunochemotherapy is the standard first-line treatment for non-small cell lung cancer (NSCLC). However, the ideal combination strategy and maintenance regimen remain uncertain. This study aims to compare the clinical efficacy of different first-line maintenance regimens for advanced EGFR/ALK (epidermal growth factor receptor/anaplastic lymphoma Kinase) negative NSCLC and explore the eligibility of chemo-free maintenance.Methods: We conducted a retrospective evaluation of 1,510 EGFR/ALK negative NSCLC patients who received immune checkpoint inhibitors (ICIs) treatment in our center from 2019 to 2021. Patients who had controlled disease after 2-6 cycles of first-line ICIs in combination with platinum-based doublet chemotherapy with or without anti-angiogenesis were included. Four maintenance regimens were analyzed: ICIs plus platinum-free chemotherapy with (group 1, I+C+A) or without anti-angiogenesis maintenance (group 2, I+C), single-agent ICIs maintenance (group 3, I) or ICIs plus anti-angiogenesis maintenance (group 4, I+A). For group 3-4, rechallenge with initial chemo-agents was given upon the first progression, those who achieved controlled disease were repeatedly followed by another chemo-free period. The primary outcome was progression-free survival (PFS). Notably, for group 3-4, PFS was characterized as the duration between treatment initiation and failure of rechallenge (last disease progression).Results: In total, 140 eligible patients in the maintenance phase were analyzed, with 20, 40, 42, and 38 patients in groups 1 to 4, respectively, displaying comparable baselines. Median PFS was similar in the I+C+A maintenance group (22.6 months), I+C maintenance group (21.0 months), and I+A maintenance group (21.5 months), whereas PFS was inferior in group 4 with I maintenance alone (13.4 months). Median chemo-free duration were 6.3 months in I maintenance group, while 13.5 months in I+A maintenance group. During the maintenance period of group 1 to 4, 25%, 25%, 19%, and 42% of patients experienced partial response (PR) again, respectively. Fifty-five percent, 65%, 48% and 61% of patients sustained durable disease control at the end of follow-up. In group 4, 39% of patients received progressive disease (PD) and rechallenge initial chemo-agents. Fifty percent of patients achieved PR and resumed to chemo-free maintenance.Conclusions: We showed that following first-line immunochemotherapy, chemo-free maintenance by ICIs plus anti-angiogenesis and on-demand chemo-rechallenge provided comparable efficacy to chemo-on maintenance in terms of PFS, thus allowing the minimization of cytotoxic drugs without compromising therapeutic effectiveness. In addition, anti-angiogenesis is essential during chemo-free maintenance.