Cancer Sci. 2020 Oct 3. doi: 10.1111/cas.14671. Online ahead of print.
Anaplastic lymphoma kinase (ALK) inhibition is expected to be a promising therapeutic strategy for ALK-positive malignancies. We aimed to examine the efficacy and safety of alectinib, a second-generation ALK inhibitor, in patients with relapsed or refractory ALK-positive anaplastic large cell lymphoma (ALCL). This open-label, phase 2 trial included patients (age ≥ 6 years) with relapsed or refractory ALK-positive ALCL. Alectinib 300 mg was administered orally twice a day (600 mg/day) for 16
cycles, and the duration of each cycle was 21 days. Patients who weighed < 35 kg were administered a reduced dose of alectinib of 150 mg twice a day (300 mg/day). Ten patients were enrolled, and the median age was 19.5 years (range 6 to 70). Objective responses were documented in eight of 10 patients (80%; 90% CI: 56.2-95.9), with six complete responses. The 1-year progression-free survival, event-free survival, and overall survival rates were 58.3%, 70.0%, and 70.0%, respectively. The median duration of therapy was 340 days. No unexpected adverse events (AE) occurred. The most common grade 3 and higher AE was a decrease in neutrophil count in two patients. Alectinib showed favorable clinical activity and was well tolerated in patients with ALK-positive ALCL who had progressed on standard chemotherapy. Based on the results of current study, Ministry of Health, Labour and Welfare in Japan has approved alectinib for the treatment of recurrent or refractory ALK-positive ALCL in February 2020.