Safety
“The percentage of patients reporting adverse events was not different in the long-term treatment-exposure patients, compared to the short-term,” Dr. Kim said.
Percentages of treatment-emergent AEs (TEAEs) and serious AEs (SAEs) according to mogamulizumab exposure were as follows:
- Less than 72 days: 26.6% TEAEs and 6.5% SAEs
- 72-170 days: 18.5% TEAEs and 3.3% SAEs
- 171-351 days: 23.4% TEAEs and 6.0% SAEs
- More than 351 days: 21.7% TEAEs and 4.3% SAEs.
“The majority of the grade 3 events occurred in the first two quartiles, not later, which is important to show,” Dr. Kim said.
Most grade 3 AEs occurred within 170 days of treatment initiation, and the median time to a grade 3 or higher AE was 109 days.
The most common treatment-related AEs in the longest exposure cohort were drug eruption (20.0%), thrombocytopenia (11.1%), stomatitis (8.9%), and anemia (8.9%).
Of all patients in this analysis, 45 experienced drug eruption, which was defined as a skin rash possibly, probably, or definitely related to the study drug.
Nine drug eruption events were grade 3, and the rest were grade 1 or 2. The median time to drug eruption was 107 days.
While drug eruption “didn’t show up early,” there is no cumulative risk with longer exposure to mogamulizumab, Dr. Kim said. Likewise, she said, autoimmune AEs were not dose-cumulative events.
There were two patients with definite autoimmune disease — a 65-year-old man with Miller Fisher syndrome (occurring 199 days after mogamulizumab initiation) and a 40-year-old woman with myositis (151 days) and myocarditis (310 days).
The investigators also identified three patients with possible autoimmune disease, including:
- Pneumonitis (310 days) in a 74-year-old woman
- Polymyalgia rheumatica (209 days) and myopathy (not available) in an 84-year-old man
- Hepatitis (144 days), pneumonitis (about 174 days), and polymyositis (about 174 days) in a 73-year-old man.
Dr. Kim and her colleagues said these data suggest prolonged treatment with mogamulizumab is not associated with an increased safety risk in patients with MF or SS. And the manageable safety profile of mogamulizumab meant that patients who derived a clinical benefit could remain on the drug for an extended period of time.
The MAVORIC trial was sponsored by Kyowa Hakko Kirin Pharma. Dr. Kim reported relationships with Merck, Portola Pharmaceuticals, Soligenix, Takeda, TetraLogic Pharmaceuticals, Kyowa Kirin, Seattle Genetics, Medivir, Neumedicines, Eisai, Innate Pharma, Galderma, Miragen Therapeutics, Forty Seven, and Horizon Pharma. Her coinvestigators reported relationships with several companies.
The T-cell Lymphoma Forum is organized by Jonathan Wood & Associates, which is owned by the same company as this news organization.