The efficacy of immune checkpoint inhibitors following discontinuation for long-term response or toxicity in advanced or metastatic non-small-cell lung cancers: A retrospective study

Abstract

Background and aims: The treatment of metastatic non-small-cell lung cancer (NSCLC) has been revolutionized by the arrival of immune checkpoint inhibitors (ICI). For patients without immune related adverse events (irAEs), it is recommended to continue the treatment as long as it provides clinical benefit or until unacceptable toxicity appears. The aim of our study was to evaluate survival data among patients with advanced or metastatic NSCLC following ICI discontinuation for reasons of long-term response or toxicity (irAEs).

Methods: We included all patients with advanced or metastatic NSCLC treated with nivolumab and pembrolizumab at the Centre Jean Perrin, Clermont-Ferrand, France (January 1, 2016 to May 31, 2019). We focused on two groups in this study population: "Voluntary treatment discontinuation" (medical decision as a result of long-term response and patient decision) and "Treatment discontinuation due to toxicity" (irAEs). The primary endpoint was to evaluate the postdiscontinuation outcomes of these two groups: progression-free survival (PFS) and overall survival (OS), and rechallenge in the "voluntary discontinuation" group.

Results: The final analysis concerned 146 patients, including 10 (7%) in the "discontinuation due to toxicity" group, 11 (8%) in the "voluntary discontinuation" group, 100 (68%) who discontinued treatment as a result of progression and 25 (17%) whose treatment was still on-going. The median PFS in the "discontinuation due to toxicity" group was not reached, and in the "voluntary discontinuation" group (n = 11) was 37 months (p = 0.4), versus 2 months in the progression group (p < 0.001). The median OS in "discontinuation due to toxicity," and in the "voluntary discontinuation" groups was not reached (p = 0.5), versus 10 months in the progression group (p < 0.001).

Conclusion: Treatment discontinuation following long-term response to ICI treatment showed sustained response and long-term survival after discontinuation. The incidence of irAEs was associated with better long-term survival, even after ICI discontinuation.

Keywords: immune‐related adverse events; immunotherapy; long‐term response; metastatic non‐small‐cell lung cancer; nivolumab; pembrolizumab; treatment discontinuation.