The use of mogamulizumab before allogeneic hematopoietic stem-cell transplantation in aggressive adult T-cell leukemia/lymphoma is associated with an increased risk of acute graft-versus-host disease (GVHD), which leads to an inferior overall survival, investigators report in the Journal of Clinical Oncology.
Mogamulizumab is an anti-CCR4 monoclonal antibody that showed promise in small clinical studies when added to conventional chemotherapy as first-line treatment. It was recently approved for the treatment of adult T-cell leukemia/lymphoma in Japan, and eventually may be approved in the U.S. and other countries, said Shigeo Fuji, MD, of the department of hematopoietic stem-cell transplantation, National Cancer Center Hospital, Tokyo, and his associates.
The agent significantly depleted regulatory T cells for several months in animal models. This prompted concern regarding the possibility of exacerbating GVHD in human patients who don’t respond completely to first-line chemotherapy and then undergo stem-cell transplantation. “However, no direct evidence has demonstrated [regulatory T-cell] depletion in humans,” the investigators noted.
To examine this issue, they assessed clinical outcomes in a cohort of 996 patients across Japan who had aggressive adult T-cell leukemia/lymphoma, were aged 20-69 years, were diagnosed in 2000-2013, and received intensive, multiagent chemotherapy before undergoing allogeneic hematopoietic stem-cell transplantation.
Grade 2-4 acute GVHD developed in 381 of 873 patients who didn’t receive mogamulizumab (43.6%), compared with 47 of 81 patients who did receive the agent (58.0%), for a relative risk of 1.33 (P = .01). Grade 3-4 acute GVHD developed in 150 patients who didn’t receive mogamulizumab (17.2%), compared with 25 who did (30.9%), for an RR of 1.80 (P less than .01) .
The agent not only raised the rate of GVHD, it also increased the severity of the disorder. GVHD was refractory to systemic corticosteroids in 23.5% of patients who didn’t receive mogamulizumab, compared with 48.9% of those who did, for an RR of 2.09 (P less than .01), the investigators reported (J Clin Oncol. 2016. doi: 10.1200/JCO.2016.67.8250).
In addition, 1-year disease-free mortality was 25.1% without mogamulizumab, compared with 43.7% with it. The estimated 1-year overall survival was 49.4% without mogamulizumab, compared with 32.3% with it. And in multivariable analyses, receiving mogamulizumab before undergoing stem-cell transplantation was a significant risk factor for both disease-free mortality (hazard ratio, 1.93) and overall mortality (HR, 1.67).
“All hematologists should take the risks and benefits of mogamulizumab into consideration before they use [it] in transplantation-eligible patients,” Dr. Fuji and his associates said.