New Asthma Drug Depemokimab Shows Promise in Severe Cases & Comorbidities

A new treatment option for severe asthma is now available in the United States, offering a potential breakthrough for patients who experience frequent exacerbations despite standard care. December 16, 2025, the U.S. Food and Drug Administration (FDA) approved Exdensur (depemokimab-ulaa), a biologic medication administered twice yearly. This marks the first ultra-long-acting biologic of its kind for this indication.

Exdensur is designed for adults and pediatric patients aged 12 years and older with severe asthma characterized by an eosinophilic phenotype – meaning the condition is driven by elevated levels of eosinophils, a type of white blood cell involved in inflammation. It functions as an add-on maintenance treatment, meaning it’s used in conjunction with existing asthma medications, not as a replacement.

The approval is based on data from the SWIFT-1 and SWIFT-2 phase III clinical trials. These studies demonstrated a significant reduction in the rate of annualised asthma exacerbations – commonly known as asthma attacks – in patients receiving depemokimab compared to those receiving a placebo, in addition to their standard asthma treatment. Specifically, the trials showed a 58% and 48% reduction in exacerbation rates over 52 weeks, respectively. (rate ratio (95% confidence interval) p-value: SWIFT-1 0.42 (0.30, 0.59) p<0.001 and SWIFT-2 0.52 (0.36, 0.73) p<0.001).

Beyond reducing the overall number of attacks, the trials also indicated a decrease in exacerbations severe enough to require hospitalization or a visit to the emergency department. While the reduction was described as numerically fewer, the data suggest a potential for lessening the burden on healthcare resources for this patient population. In SWIFT-1 and SWIFT-2, patients treated with depemokimab experienced exacerbations requiring hospitalization and/or emergency department visits in 1% and 4% of cases, respectively, compared with 8% and 10% in the placebo groups.

The development of depemokimab represents a shift in treatment paradigms for severe asthma, according to experts. The medication targets interleukin-5 (IL-5), a key driver of eosinophilic inflammation. What sets depemokimab apart is its extended dosing interval. Traditional biologic therapies for asthma often require more frequent administration, which can impact patient adherence and convenience. Depemokimab’s twice-yearly dosing schedule aims to address these challenges.

The extended duration of action is achieved through a unique modification to the antibody’s structure. As explained in research published in PubMed, depemokimab incorporates an amino acid modification (YTE mutation) in the Fc region, increasing its affinity for Fc receptors and promoting antibody recycling. This process significantly extends the drug’s half-life, allowing for the less frequent dosing schedule.

An estimated 2 million Americans live with severe asthma, and approximately half continue to experience frequent exacerbations and hospitalizations, highlighting the need for novel therapeutic approaches. The availability of depemokimab offers a new option for these patients.

the potential benefits of depemokimab extend beyond asthma. Research suggests it may also be effective in treating chronic rhinosinusitis with nasal polyps (CRSwNP), a condition often co-occurring with severe asthma. Clinical trials have shown that depemokimab can reduce nasal polyp endoscopy scores and nasal obstruction in patients with CRSwNP. This dual-action potential allows for a more integrated approach to managing patients with both conditions.

Cristiano Caruso, Director of the Allergy and Clinical Immunology Unit at the Fondazione Policlinico A. Gemelli IRCCS Roma – Catholic University of the Sacred Heart, emphasized the potential for disease modifying effects. This means the treatment aims not just to control symptoms, but to alter the long-term course of the disease. He noted that the drug is designed to treat simultaneously patologies strettamente correlated (closely related pathologies).

Ongoing research is exploring the use of depemokimab in other eosinophilic inflammatory conditions, including granulomatosis with polyangiitis and hypereosinophilic syndromes. These investigations aim to establish a broader therapeutic strategy for diseases driven by type 2 inflammation and elevated eosinophil levels. The goal is to develop a treatment approach that can address a wide range of conditions characterized by these underlying inflammatory mechanisms.

While depemokimab represents a significant advancement, it’s important to remember that it’s not a cure for asthma. It’s an add-on therapy designed to improve symptom control and reduce exacerbations in a specific subset of patients with severe eosinophilic asthma. As with any medication, potential side effects should be discussed with a healthcare professional.