GSK expands its respiratory portfolio with FDA-approved long-acting biologic exdensur

UK—British pharmaceutical GSK has received approval from the US Food and Drug Administration (FDA) for Exdensur (depemokimab), its new add-on maintenance therapy for severe asthma.

 The decision marks a significant milestone for the UK-based pharmaceutical giant, as Exdensur becomes the first long-acting interleukin-5 (IL-5)-targeting monoclonal antibody to be administered twice a year.

The therapy is indicated for patients aged 12 years and older with severe asthma characterized by an eosinophilic phenotype.

The FDA based its approval on results from two Phase III clinical trials, SWIFT-1 (NCT04719832) and SWIFT-2 (NCT04718103).

Over a 52-week treatment period, Exdensur reduced annualized asthma exacerbations by up to 58%, demonstrating strong efficacy across both trials.

In addition, the drug significantly reduced the rate of hospitalisation for asthma.

 Only 1% and 4% of patients receiving Exdensur in the SWIFT-1 and SWIFT-2 trials, respectively, required hospital visits, compared to 8% and 10% among those in the placebo group.

Unlike other maintenance treatments for severe asthma, Exdensur stands out for its biannual dosing schedule.

Most competing biologics require more frequent injections—ranging from monthly to biweekly—making Exdensur a more convenient option for patients managing chronic symptoms.

According to Kaivan Khavandi, GSK’s Senior Vice-President and Head of Global Respiratory, Immunology, and Inflammation R&D, the new therapy’s extended dosing interval could “redefine patient care” and strengthen the role of biologic treatments for patients who continue to experience flare-ups despite standard therapies.

On 15 December, GSK received a parallel approval for Exdensur from the UK Medicines and Healthcare Regulatory Agency (MHRA).

In the UK, the drug is indicated for treating both severe asthma and severe chronic rhinosinusitis with nasal polyps.

Exdensur’s launch expands GSK’s robust respiratory portfolio, which already includes the widely prescribed add-on asthma and chronic obstructive pulmonary disease (COPD) treatment Nucala (mepolizumab).

Nucala generated £1.78 billion (about USD 2.37 billion) in 2024, making it the third best-selling severe asthma biologic that year, behind Sanofi and Regeneron’s Dupixent (dupilumab) and Genentech’s Xolair (omalizumab), co-developed by Novartis and Roche.

Despite its unique twice-yearly dosing advantage, Exdensur will compete in a crowded market for asthma biologics.

Leading rivals include Dupixent, an IL-4 receptor alpha blocker approved in 2018, which remains the top-selling severe asthma therapy.

 GlobalData projects Dupixent’s asthma-related sales to peak at USD4.8 billion by 2031, while Exdensur is expected to reach USD935 million in the same year.

GSK may benefit from evolving market dynamics, especially as Xolair faces the expiry of its US patent in November 2025, paving the way for biosimilars like Celltrion’s newly approved Omlyclo.