Immunotherapy Following Anaplastic Lymphoma Kinase Inhibitor Therapy for Patients with Anaplastic Lymphoma Kinase‑Positive Non‑small Cell Lung Cancer in Japan.

Background: Although anaplastic lymphoma kinase inhibitors (ALKis) are the effective initial treatment for patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC), most patients experience resistance to ALKis, leading to the need for alternative therapies. Immune checkpoint inhibitors (ICIs) are a standard NSCLC treatment. On the other hand, their efficacy remains unclear for ALK-positive NSCLC.

Objective: We aim to describe the treatment patterns and treatment outcomes for patients with ALK-positive NSCLC receiving later-line ICI treatment.

Methods: This retrospective cohort study used claims data from Japanese acute care hospitals and included patients with lung cancer (International Classification of Diseases, 10th version (ICD-10), code: C34) diagnosed between 1 December 2015 and 31 January 2023. We extracted patients who received ALKis as first-line therapy and subsequent lines of treatment. Patient characteristics and treatment patterns and durations were descriptively summarized. Time to treatment discontinuation (TTD) for ICIs was examined using Kaplan-Meier estimates.

Results: Of 478 patients who received ALKi as first-line treatment, 30 received ICIs, 249 ALKis, and 154 non-ICI/ALKi therapy as second-line treatment. Most patient characteristics showed no differences among the groups. ICIs were more likely to be administered to patients who underwent shorter durations of ALKi treatment. The median TTD for ICIs was 66 days, with a 1 year TTD rate of 13%.

Conclusions: Given the rarity of ALK-positive NSCLC, this study contributes to add evidence through an expanded database and increased sample size, supporting previous suggestions that ICIs have limited effectiveness in patients positive for ALK.