Evidence on prognosis and optimal treatment for patients with advanced NSCLC harboring non-EML4-ALK fusions (rare ALK) remains limited. In a retrospective real-world cohort from 29 centers across six countries, overall survival (OS) appeared shorter in patients with rare ALK fusions (n = 51) compared with those with EML4-ALK fusions (n = 277; median 27 vs. 57 months, p = 0.08). Among patients receiving first-line therapy, those with rare ALK fusions experienced significantly shorter progression-free survival (PFS) with platinum-based chemotherapy than with a TKI (5 vs. 23 months; HR 3.1, 95% CI 1.2-8, p = 0.02). In contrast, for patients treated first-line with an ALK-TKI, ORR (85% vs. 74%; p = 0.9) and PFS (median 25 vs. 23 months; HR 0.9, 95% CI 0.6-1.5) were similar between rare ALK and EML4-ALK groups. These findings support TKIs as preferred first-line therapy for advanced NSCLC with rare ALK fusions.
