Immunotherapy with Pembrolizumab beyond Progression and Local Ablative Therapy in Oligoprogressive metastatic NSCLC.

BACKGROUND: Immune checkpoint inhibitors (ICIs) targeting PD-(L)1 are standard first-line treatment for non-oncoge-addicted metastatic non-small cell lung cancer (mNSCLC). While disease progression typically requires therapy change, patients with oligoprogression (≤5 progressing sites) often continue ICI in combination with local ablative therapies. In this retrospective study, we aim to evaluate the characteristics and outcomes of this treatment approach. METHODS: We retrospectively analyzed mNSCLC patients receiving first-line ICI-based therapy at University Hospital Basel (January 2016-March 2022). Patients with documented disease progression were categorized into: treatment beyond progression (BPD), second-line treatment (2L), or best supportive care (BSC). We compared patient characteristics and overall survival (OS). RESULTS: Of 104 patients receiving first-line ICI treatment, 65 experienced disease progression: 21 (32%) received BPD, 30 (46%) received 2L, and 14 (22%) received BSC. Patient and disease characteristics were similar across groups, except for higher brain metastasis frequency in the BPD group (BPD: 67% vs 2L: 20% vs BSC: 29%; p=0.002). After median follow-up of 17.9 months, time to first progression (5.4 vs 5.3 months, p=0.5) and median OS after progression (9.1 vs 10.9 months, p=0.35) were similar between BPD and 2L groups. CONCLUSION: In this retrospective analysis, treatment BPD was not associated with an improved prognosis compared to 2L therapy. There is a need to improve and implement criteria to select patients who truly benefit from this treatment approach.