A phase 2 trial of CHOP with anti-CCR4 antibody mogamulizumab for older patients with adult T-cell leukemia/lymphoma

ABSTRACT: No standard of care for older patients with aggressive adult T-cell leukemia/lymphoma (ATL) has been established. We evaluated the efficacy of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) every 2 weeks with mogamulizumab (Moga; Moga-CHOP-14) for older patients with untreated ATL. In this multicenter phase 2 trial, patients aged ≥66 years and those aged 56 to 65 years ineligible for transplantation received 6 cycles of Moga-CHOP-14, followed by 2 cycles of Moga monotherapy. The primary end point was 1-year progression-free survival (PFS). Secondary end points 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 CC chemokine receptor 4 (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, 24.9-47.6), with a median follow-up of 1.6 years. The 1-year OS and EFS were 66.0% and 29.9%, respectively. CR and ORR were 64.6% and 91.7%. No unexpected toxicities were observed. Of 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 cAEs were associated with better OS. This study showed that Moga-CHOP significantly improved PFS, although the optimal interval for CHOP remains undetermined. Moga-CHOP is now considered a preferable first-line treatment for this patient population. This trial was registered at https://jrct.mhlw.go.jp/en-top as #jRCTs041180130.