US FDA approves mepolizumab for treatment of hypereosinophilic syndrome

US FDA approves mepolizumab for treatment of hypereosinophilic syndrome

The USFDA has recently approved mepolizumab (Nucala) for treatment of hypereosinophilic syndrome (HES) in adults and children aged 12 years and older.

The drug can be administered for patients diagnosed with HES for six months or longer without another identifiable non-blood related cause of the disease, said the agency. The drug comes as a new treatment for HES patients in nearly 14 years. The FDA has granted the approval to GlaxoSmithKline.

HES is a heterogeneous group of rare disorders associated with persistent eosinophilia with evidence of organ damage. Symptoms include skin rashes, itching, asthma, difficulty breathing, abdominal pain, vomiting, diarrhea, arthritis, muscle inflammation, congestive heart failure, deep venous thrombosis and anaemia.

Mepolizumab was evaluated in a randomized, double-blind, multicentre, placebo-controlled trial in 108 patients with HES. In the study, patients were randomly assigned to receive mepolizumab or placebo by injection every four weeks.

The trial compared the proportion of subjects who experienced a HES flare during the 32-week treatment period. A HES flare was defined as worsening of clinical signs and symptoms of HES or increasing eosinophils on at least two occasions. The trial compared the proportions of patients with at least one flare over a 32-week treatment period, as well as the time to the first flare. Fewer patients in the mepolizumab treatment group (28%) had HES flares compared to patients in the placebo group (56%), with a 50% relative reduction. In addition, the time to the first HES flare was later, on average, for patients treated with mepolizumab vs. placebo.