Glaxosmithkline plc has won FDA approval to market Nucala (mepolizumab) for use in children as young as 6 with severe eosinophilic asthma (EA). The therapy already had FDA approval as an add-on maintenance treatment for kids with the same condition ages 12 and older. Approval of the sBLA, submitted last November, catches the U.S. market up to the EU, where Nucala has been approved as an add-on treatment for children ages 6 to 17 since August 2018.
A first-in-class monoclonal antibody that targets IL-5, Nucala gained its initial U.S. regulatory approval in 2015 for the treatment of severe EA in adults. Provided as a 100-mg subcutaneous injection for the 12-and-older group, it's believed to work by preventing IL-5 from binding to its receptor on the surface of eosinophils. Inhibiting IL-5 binding in that way reduces blood eosinophils without completely depleting them. (See BioWorld, Nov. 6, 2015.)
Global sales of Nucala, a key part of London-based GSK's respiratory portfolio, hit $751 million in 2018 and are expected to climb to $922 million this year, based on a consensus estimate of eight analyst projections compiled by Cortellis. But challengers abound.
The drug already competes in the 12-and-older population with other IL-5 receptor antagonists, such as Astrazeneca plc's Fasenra (benralizumab) and the anti-IL-4R drug Dupixent (dupilumab) from Regeneron Pharmaceuticals Inc. Nucala is the first of the trio to be approved for the condition in the 6-to-11-year age group in the U.S. and is also the only anti-IL-5 biologic approved for pediatric use from ages 6 to 17 in Europe in severe EA. However, Dupixent's developers are already in the chase for the younger market, with a phase III study underway to evaluate its efficacy in children 6 to 11 with uncontrolled persistent asthma.
The majority of asthma patients are well-controlled on inhaled corticosteroids and long-acting beta agonists, and relatively few patients reach the level of asthma severity at which biologics such as Nucala become applicable. Severe persistent asthma is estimated to affect between 5% and 10% of asthma sufferers, with eosinophilic asthma representing less 5% of all cases.
The FDA approval was supported by an open-label study in children, 6 to 11, with severe EA as well as in trials in adults and adolescents, GSK said. The 52-week long-term phase of the study showed that the safety profile in the 6-to-11 group was similar to what was seen in patients over 12.
In addition to severe EA, Nucala is approved for the treatment of eosinophilic granulomatosis with polyangiitis (previously known as Churg-Strauss syndrome) in the U.S., EU and Japan and for bronchial asthma in Japan.
In June, the FDA approved two additional administering methods for Nucala, as an autoinjector and as a prefilled safety syringe to be administered once every four weeks.