The US Food and Drug Administration has approved mogamulizumab for adult patients with relapsed or refractory mycosis fungoides (MF) or Sézary syndrome (SS) after at least one prior systemic therapy.

The approval of mogamulizumab, a CC chemokine receptor type 4 (CCR4) directed monoclonal antibody, was based on a randomized, open-label, multicenter trial in patients with active MF or SS after at least one prior systemic therapy.

Patients enrolled had a median of 3 prior therapies.

The trial randomized 372 patients (44% with SS) to either mogamulizumab or vorinostat.

Progression-free survival (PFS) was statistically significantly longer in the mogamulizumab arm.

The estimated median PFS was 7.6 months (95% CI: 5.6, 10.2) for those treated with mogamulizumab compared with 3.1 months (95% CI: 2.8, 4.0) in the vorinostat arm (hazard ratio 0.53; 95% CI: 0.41, 0.69).

The confirmed overall response rate was 28% and 5%, respectively (p<0.001).

“Mycosis fungoides (MF) and Sézary syndrome (SS) can be disfiguring, and debilitating. MAVORIC, the largest study of systemic therapy ever conducted in MF and SS, showed that mogamulizumab prolonged progression-free survival compared to vorinostat in patients with relapsed or refractory MF or SS,” said Jeffrey S. Humphrey, MD, President of Kyowa Kirin Pharmaceutical Development, Inc. “We look forward to the publication of MAVORIC’s primary results and to ongoing scientific exchange within the medical and academic communities."

Because CTCL manifests itself in skin lesions, it is often mistaken for other non-critical skin conditions, which can delay conclusive diagnosis and treatment options. MF and SS are the two most common subtypes of CTCL.

MF is the most common subtype, accounting for 50-70% of cases.

It is a slow progressing form of lymphoma that can involve the skin, blood, lymph nodes and organs, and may be associated with severe infections.

SS accounts for approximately 3% of CTCL cases and is a more aggressive, leukaemic form of CTCL.

The most common adverse reactions (reported in ≥20%) were rash, infusion-related reactions, fatigue, diarrhoea, musculoskeletal pain, and upper respiratory tract infection.

Serious adverse reactions occurred in 36% of patients, most often from infection (16% of all patients).

The prescribing information includes warnings for dermatologic toxicity, infusion reactions, infections, autoimmune complications, and complications of allogeneic hematopoietic stem cell transplantation, including severe and refractory graft-versus-host disease.

Source: FDA