GSK plc (GSK) just scored a significant FDA win that could make life considerably easier for people battling severe asthma. On Tuesday, the agency approved Exdensur (depemokimab-ulaa) as an add-on maintenance treatment for severe asthma characterized by an eosinophilic phenotype in patients aged 12 and older.

Here's what makes this interesting: patients only need two doses per year. That's a pretty appealing proposition compared to some asthma biologics that require monthly or even more frequent injections.

What the Clinical Trials Showed

The FDA approval stems from data out of two Phase 3 trials called SWIFT-1 and SWIFT-2. In both studies, depemokimab demonstrated sustained reduction in exacerbations with just two annual doses versus placebo, both combined with standard care.

The numbers are compelling. Treatment with depemokimab resulted in a 58% reduction in annualized asthma exacerbations (that's medical speak for asthma attacks) over 52 weeks in SWIFT-1, and a 48% reduction in SWIFT-2.

Perhaps more importantly for patients worried about serious complications, the drug showed promise in preventing severe episodes. In SWIFT-1 and SWIFT-2, patients on depemokimab experienced far fewer exacerbations requiring hospitalization or emergency department visits—just 1% and 4% respectively—compared with 8% and 10% in the placebo groups.

A pre-specified pooled analysis of both trials revealed an even more dramatic finding: a 72% reduction in the annualized rate of clinically significant exacerbations requiring hospitalization or emergency visits over 52 weeks for depemokimab compared with placebo.

What's Next

Depemokimab recently received marketing authorization from the U.K.'s Medicines and Healthcare products Regulatory Agency and earned a positive CHMP opinion in Europe, with an approval decision expected in the first quarter of 2026.

GSK shares climbed 1.21% to $49.37 during premarket trading on Tuesday, trading near the stock's 52-week high of $49.39.