CHICAGO – The anti-CCR4 monoclonal antibody mogamulizumab was superior to other investigator-selected therapies for the treatment of patients with relapsed/refractory adult T-cell leukemia-lymphoma (ATL), based on results from 71 patients in a prospective, multicenter, randomized study reported at the annual meeting of the American Society of Clinical Oncology.
Commonly used cytotoxic regimens provided limited therapeutic benefit for these patients, but mogamulizumab resulted in an objective response rate that supports its therapeutic potential in this setting, reported Dr. Adrienne Alise Phillips of New York Presbyterian/Weill Cornell Medical College, New York.
Mary Jo Dales/Frontline Medical News
Dr. Adrienne Alise Phillips
A malignancy of T-cells infected with HTLV-1, ATL has a poor prognosis with a median overall survival of less than 3 months in patients with relapsed/refractory disease. CCR4 is expressed in over 90% of ATL patients, and mogamulizumab is approved in Japan for ATL as well as for peripheral T-cell lymphoma and cutaneous T-cell lymphoma.
The 71 patients in the study were from the United States, the European Union and Latin America. The study is the largest randomized clinical trial of relapsed/refractory adult T-cell leukemia-lymphoma thus far conducted. The patients were randomized in 2:1 fashion 47:24 patients) to mogamulizumab, 1.0 mg/kg, given weekly for the first 4-week cycle and then biweekly, or to one of three investigator choice regimens [gemcitabine and oxaliplatin, DHAP (dexamethasone, high-dose cytarabine, and cisplatin), or pralatrexate]. Patients who were in the investigator-choice arm and whose disease progressed were permitted to cross over to mogamulizumab.
The primary endpoint was objective response rate based on modified Tsukasaki criteria and assessed by the treating investigator and in blinded fashion by independent review.
The objective response rate in the mogamulizumab-treated group was 23.4% (11 of 47) by independent review and 34% (16 of 47) by the treating investigator. In the investigator choice group, the overall response rate was 2 of 24 by independent review and 0 of 24 by the treating investigator.
The confirmed objective response rate after 1 month in the mogamulizumab-treated group was 10.6% by independent review and 14.9% by the treating investigator; there were no confirmed responses in the investigator-choice arm. Of 18 patients who crossed over to mogamulizumab, 3 responded. The median duration of response for mogamulizumab was 5 months; one patient had a complete response that lasted over 9 months and the survival data are not yet mature.
Mogamulizumab had few drug-related adverse events, primarily infusion reactions (46.8%), rash/drug eruption (25.5%) and infections (14.9%).
Dr. Phillips disclosed ties to Celgene, Genentech, and Takeda, as well as research funding from Kyowa Hakko Kirin, the sponsor of the study.
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