Japan’s Ministry of Health, Labour and Welfare (MHLW) has approved Exdensur (depemokimab), developed by GSK plc, for the treatment of severe or refractory bronchial asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). The approval applies to patients whose conditions remain inadequately controlled with existing standard therapies.
With this decision, Exdensur becomes the first and only ultra-long-acting biologic approved in Japan for both severe asthma and CRSwNP. The therapy is designed for twice-yearly dosing and targets type 2 inflammation, a key disease driver in both conditions.
The regulatory approval is supported by data from the phase III SWIFT and ANCHOR clinical trial programmes. In the SWIFT-1 and SWIFT-2 studies, depemokimab demonstrated sustained efficacy in reducing asthma exacerbations when administered every six months alongside standard of care, compared with placebo. Over a 52-week period, treatment resulted in reductions of 58% and 48% in annualised asthma exacerbation rates in SWIFT-1 and SWIFT-2, respectively. Patients receiving depemokimab experienced fewer asthma attacks per year than those in the placebo groups.
Efficacy in CRSwNP was established through the ANCHOR-1 and ANCHOR-2 trials, which showed significant improvements in nasal polyp size and nasal obstruction, two key indicators of disease severity. At 52 weeks, depemokimab led to meaningful reductions in nasal polyp scores and improvements in nasal obstruction scores compared with placebo, when both were given in addition to standard treatment with intranasal corticosteroids.
Across the SWIFT and ANCHOR studies, depemokimab was generally well tolerated, with safety outcomes comparable to placebo. The trials reported similar rates and severity of adverse events between treatment and control groups.
Severe asthma remains a significant clinical challenge in Japan, with patients often experiencing frequent exacerbations, hospitalisations and disease progression despite available therapies, contributing to higher healthcare utilisation and costs. CRSwNP is also associated with a high disease burden, with many patients continuing to experience persistent symptoms such as nasal obstruction, loss of smell and sleep disturbance, even after surgery or systemic corticosteroid treatment. Nearly half of patients with CRSwNP are estimated to remain inadequately controlled.
Depemokimab has been engineered with an extended half-life, allowing sustained suppression of type 2 inflammation through twice-yearly administration. The drug binds to interleukin-5 (IL-5), a cytokine central to eosinophilic inflammation, which plays a major role in the pathology of both severe asthma and CRSwNP.
The approval in Japan represents the third regulatory clearance for depemokimab, following earlier authorisations by the US Food and Drug Administration and the UK Medicines and Healthcare products Regulatory Agency. The therapy has also received a positive opinion from the European Medicines Agency’s Committee for Medicinal Products for Human Use and is currently under regulatory review in additional markets, including China.
Beyond asthma and CRSwNP, depemokimab is being evaluated in an extensive phase III development programme across other diseases driven by type 2 inflammation. Ongoing studies include trials in eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome, and uncontrolled moderate to severe chronic obstructive pulmonary disease with type 2 inflammation.
The approval further strengthens GSK’s respiratory portfolio, which spans biologics, inhaled medicines and vaccines aimed at improving outcomes across asthma, COPD and other chronic respiratory and inflammatory diseases.
