Feasibility and Efficacy of Lorlatinib in Japanese Patients With Relapsed/Refractory ALK ‐Aberrant Neuroblastoma

Lorlatinib, a third-generation ALK inhibitor, was administered off-label to five heavily pretreated patients with relapsed or refractory ALK-aberrant neuroblastoma. ALK alterations included F1174L, R1275Q, BEND5::ALK fusion, and ALK amplification; three patients had MYCN amplification. Best responses were three partial responses and two disease progressions. The longest progression-free survival (6.7 months) occurred in a patient with F1174L and non-amplified MYCN, whereas rapid progression was observed in two MYCN-amplified cases. Lorlatinib was generally well tolerated with manageable adverse events. These findings suggest that lorlatinib is a feasible therapeutic option in ALK-aberrant neuroblastoma and that clinical heterogeneity in treatment response warrants further investigation.