Abstract

Purpose
Alectinib has been approved for Anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC) at 300mg twice daily in Japan, lower than global standard of 600mg twice daily. This study evaluated the clinical relevance of the reduced dose by comparing outcomes between the two doses.
Materials and Methods
This study included patients with advanced ALK-positive NSCLC who received alectinib at Samsung Medical Center, Korea. The progression-free survival (PFS), overall survival, cumulative incidence of central nervous system (CNS) progression, and safety profiles were retrospectively reviewed and compared.
Results
Among 306 patients, 32 and 274 received alectinib at either 300 or 600 mg twice daily, respectively. The 300 mg group showed a slight but not significant advantage in PFS (HR 0.82, 95% CI, 0.44-1.51; p=0.51) and overall survival (HR 0.51, 95% CI, 0.20-1.21; p=0.13). Superior outcome with 300mg was remarkable in patients with lower body weight (≤60 kg), but diminished in patients with higher body weights. Patients with baseline brain metastasis in the 300mg group exhibited a slight increase in incidence of CNS failure (HR 1.76, 95% CI, 0.53-5.8; p=0.36). Although the safety profiles were mostly mild, adverse events were more frequent in the 600mg group, 50% of which requiring dose reduction.
Conclusion
Alectinib at 300 mg twice daily seems an acceptable dose in East Asians with ALK-positive NSCLC. Notably, our data favor 300 mg twice daily in patients with lower body weight and no baseline brain metastasis, considering the more tolerable safety profiles and the potential to reduce medical costs.

• Keywords: Carcinoma, Non-Small-Cell Lung, Anaplastic lymphoma kinase, Alectinib