Mepolizumab

GSK’s blockbuster respiratory drug Nucala has secured a China label expansion for certain patients with inflamed sinuses. But a more important challenge on the way to hitting its multibillion-dollar peak sales projections is on the horizon. Nucala could reach $2.35 billion in 2026 sales, according to GlobalData analysts. But this sky-high forecast is mainly driven by a potential new expansion in chronic obstructive pulmonary disease — the third leading cause of death worldwide. Late-stage data are still yet to be detailed, but a PDUFA date is set for May 7. On Friday, China’s NMPA greenlit the drug as an add-on to intranasal corticosteroids for people with chronic rhinosinusitis with nasal polyps (CRSwNP) that are inadequately controlled. The approval marks the third indication for Nucala in the country, following previous green lights for severe asthma and eosinophilic granulomatosis with polyangiitis. There are around 30 million people in China with CRSwNP, according to GSK. The latest approval gives them an alternative option to surgery and repeat use of oral corticosteroids, GSK’s head of respiratory and immunology R&D Kaivan Khavandi said in a release. Nucala is also approved for CRSwNP in the US, alongside other indications including severe asthma, hypereosinophilic syndrome and eosinophilic granulomatosis with polyangiitis. The product reached £444 million ($550 million) in sales in the third quarter of 2024. While Nucala’s market expansion in China is welcome, the bigger commercial focus for GSK is COPD. In September, Nucala passed a Phase 3 test for the disease, which affects more than 390 million people worldwide. The drugmaker has yet to share details of the data publicly, but has already submitted them to the FDA. In December, CEO Emma Walmsley told investors at the Redburn Atlantic CEO Conference that Nucala could become “the first once-monthly biologic proven to reduce exacerbations across the full spectrum of COPD patients.” And “that’s important when you look at the competitive context here because we have included the most difficult-to-treat patients – those with emphysema, which I think is about a third of the market,” she added. Elsewhere, the company also has an ultra-long acting anti-IL-5 candidate, depemokimab, which is set to enter Phase 3 development for COPD this year. The drug has the potential to be efficacious when administered as little as once every six months, offering more convenience for patients.

According to information from the CDE website, GlaxoSmithKline (GSK) has submitted a marketing application for depemokimab in China. Considering the latest progress in clinical trials, the expected indication for this drug is severe eosinophilic asthma (SEA). Depemokimab is a new generation anti-interleukin 5 (IL-5) monoclonal antibody developed by GSK, characterized by a longer half-life, high binding affinity, and high potency, requiring only one injection every six months. In contrast, GSK's first-generation IL-5 monoclonal antibody, mepolizumab (trade name: Nucala), requires monthly injections and was approved for marketing in the United States in November 2015. According to GSK's financial report, global sales of mepolizumab were approximately $2 billion in 2023. Currently, depemokimab has completed four Phase III clinical studies targeting SEA and chronic rhinosinusitis with nasal polyps (CRSwNP). Two Phase III studies for SEA (SWIFT-1 and SWIFT-2) showed a significant reduction in the frequency of asthma attacks in the depemokimab group compared to the placebo group after 52 weeks of treatment. Similarly, two Phase III studies for CRSwNP (ANCHOR-1 and ANCHOR-2) also indicated a significant decrease in the total nasal endoscopic polyp score in the depemokimab group compared to the placebo group after 52 weeks of treatment. Additionally, the nasal congestion scores in the depemokimab group, assessed through a verbal rating scale (VRS) during weeks 49-52, also showed a significant reduction compared to the placebo group. Detailed data has not been publicly disclosed yet.