A phase 2 Trial of CHOP with Anti-CCR4 Antibody Mogamulizumab for older Patients with Adult T-Cell Leukemia/Lymphoma.

No standard of care for elderly patients with aggressive adult T-cell leukemia/lymphoma (ATL) has been established. We evaluated the efficacy of CHOP every 2 weeks with mogamulizumab (Moga) (Moga-CHOP-14) for untreated elderly patients with ATL. In this multicenter phase 2 trial, patients aged ≥66 years and those aged 56-65 years ineligible for transplantation received 6 cycles of Moga-CHOP-14, followed by 2 cycles of Moga monotherapy. The primary endpoint was 1-year progression-free survival (PFS). Secondary endpoints were the complete response (CR) rate, overall response rate (ORR), overall survival (OS), 1-year event-free survival (EFS), and safety. We also investigated the impact of CCR4 mutation and Moga-associated cutaneous adverse events (cAEs) on PFS and OS. The study protocol was amended to allow the dosing interval to be extended to 21 days at the physician's discretion. Among 48 evaluable patients, the 1-year PFS was 36.2% (90% confidence interval [CI], 24.9-47.6), with a median follow-up of 1.6 years. One-year OS and EFS were 66.0% (95% CI, 50.6-77.6) and 29.9% (95% CI, 17.6-43.2), respectively. CR and ORR were 64.6% (95%CI, 49.5-77.8) and 91.7% (95% CI, 80.0-97.7). No unexpected toxicities were observed. Of the 47 patients who received ≥2 cycles of CHOP, 20 (42.6%) received CHOP-14, among whom 12 (25.5%) completed 6 cycles. CCR4 mutation and Moga-associated cAE were associated with better OS. This study showed that Moga-CHOP significantly improved PFS, though the optimal interval for CHOP remains undetermined. Moga-CHOP is now considered a preferable first-line treatment for these patients. Clinical Trial Identifier: jRCTs041180130.