ATLANTA – Intravenous treatment with mogamulizumab, an investigational antibody targeting CC chemokine receptor 4, more than doubled progression-free survival (PFS), compared with oral vorinostat in a phase 3 trial of 372 patients with heavily pretreated cutaneous T-cell lymphoma (CTCL).
Courtesy ASH
Dr. Youn H. Kim
After a median of three treatment cycles, median PFS with mogamulizumab was 7.7 months vs. 3.1 months with vorinostat (hazard ratio, 0.53; 95% confidence interval, 0.41-0.69; P less than .0001), Youn H. Kim, MD, reported at the annual meeting of the American Society of Hematology.
, said Dr. Kim, the Joanne and Peter Haas, Jr. Professor for Cutaneous Lymphoma Research at Stanford (Calif.) University. Adverse effects, such as infusion reactions, were expected and manageable, she added.
Mogamulizumab is approved in Japan for treating CTCL and received an FDA breakthrough therapy designation in August 2017.
Based on audits so far, the agency might green-light mogamulizumab for previously treated CTCL by early 2018 – its first approval in the United States, Dr. Kim said in an interview.
Cutaneous T-cell lymphoma responds poorly to treatments that work in other, more common types of non-Hodgkin lymphoma. Moreover, extensive disease can destroy quality of life.
“There’s a major psychosocial impact because if you’re infected, you smell bad,” Dr. Kim said during a press briefing. “Itch is very severe – patients often cannot sleep because of it.”
Mogamulizumab is a humanized monoclonal antibody that targets CC chemokine receptor 4 (CCR4), which facilitates trafficking of lymphocytes to skin and other organs. It is defucosylated, augmenting its toxicity against malignant T cells. In a prior phase 1/2 study in the United States, mogamulizumab showed a tolerable safety profile and a 37% overall response rate – “a good response, considering that other CTCL drugs are usually in the 30% range,” Dr. Kim said.
For the phase 3 study (MAVORIC), 372 patients with previously treated stage IB to stage IVB CTCL (mycosis fungoides or Sézary syndrome) without large-cell transformation received mogamulizumab (1.0 mg/kg IV weekly for 28 days; days 1 and 15 of subsequent 28-day cycles) or vorinostat (400 mg per oral daily). Treatment continued until disease progression or intolerable toxicity. Researchers evaluated PFS based on a global composite response score that covers the skin, blood, lymph nodes, and viscera, in accordance with international consensus guidelines (J Clin Oncol. 2011 Jun 20;29(18):2598-607; doi: 10.1200/JCO.2010.32.0630).
Treatment groups resembled each other at baseline. Most had received three systemic therapies for CTCL, and some had received as many as 18. Median duration of response was 14 months in the mogamulizumab arm and 9 months in the vorinostat arm. Patients tended to respond to mogamulizumab 2 months sooner than to vorinostat (3.3 vs. 5.1 months), Dr. Kim said.
Mogamulizumab also significantly improved quality of life on the Skindex-29 Symptoms (P less than .05), Skindex-29 Function (P less than 05), and FACT-G Functional Well-Being (P less than .05) quality of life scales, which is part of what earned it a breakthrough therapy designation, Dr. Kim said.
MAVORIC is the largest randomized study to compare systemic therapies in CTCL and the first to use PFS as the primary endpoint, Dr. Kim noted. Patients’ level of CCR4 expression was not a criterion for enrollment because CCR4 is consistently and highly expressed in this disease, she noted. Thus, using mogamulizumab to treat CTCL in the United States would not require CCR4 testing.
Joseph M. Connors, MD, who specializes in lymphoid cancers at the BC Cancer Agency, a division of the British Columbia Provincial Health Services Authority, and who was not involved in the study, agreed that these data represent real headway in treating CTCL.
“I can state unequivocally that we just haven’t had effective therapy for CTCL,” he said at the press briefing. “We’ve had treatments that might help patients feel somewhat better, but we’ve had no consensus on a treatment that is right for this disease. These data provide an opportunity to have that consensus. They could create a platform for making further progress.”
Kyowa Kirin Pharmaceutical Development provided funding. Dr. Kim disclosed research and advisory relationships with Kyowa Kirin and ties to Millennium Pharmaceuticals, Seattle Genetics, Soligenix, and other companies.
SOURCE: Kim YH et al. ASH 2017 Abstract 817.