GSK's Nucala (mepolizumab) has received approval from China's National Medical Products Administration (NMPA) as an add-on therapy with intranasal corticosteroids for adult patients with chronic rhinosinusitis with nasal polyps (CRSwNP) who do not achieve adequate disease control with systemic corticosteroids or surgery. This marks the third indication for mepolizumab in China for an IL-5 mediated condition.
Kaivan Khavandi, SVP, Global Head of Respiratory/Immunology R&D at GSK, stated, “We are delighted that Nucala has been approved in China as a treatment for CRSwNP, a chronic condition for which new and effective treatments are needed. Patients now have a non-surgical option available to them and an alternative to repeated exposure to oral corticosteroids.”
Clinical Evidence Supporting Approval
The NMPA's approval is based on data from the Phase III MERIT trial, a randomized, double-blind, placebo-controlled study conducted in Japan, Russia, and China. The MERIT trial evaluated the efficacy and safety of mepolizumab in patients with CRSwNP/eosinophilic CRS (ECRS) compared to placebo over 52 weeks. The co-primary endpoints were the change from baseline in nasal obstruction visual analogue scale (VAS) score and the change in endoscopic nasal polyp score at week 52.
Results from 163 participants demonstrated that mepolizumab significantly improved nasal obstruction VAS score (mean treatment difference: -1.43 [95% CI: -2.37, -0.50]; p=0.003) and was associated with a numerical reduction in nasal polyp score at week 52 (-0.43 [-0.89, 0.03]; p=0.067). The approval is also supported by data from the global Phase III SYNAPSE study, which explored the effect of mepolizumab versus placebo in over 400 patients with CRSwNP.
Understanding Chronic Rhinosinusitis with Nasal Polyps (CRSwNP)
CRSwNP is characterized by chronic inflammation of the nasal lining, leading to the growth of soft tissue masses called nasal polyps in the sinuses and nasal cavity. Symptoms include nasal obstruction, loss of smell, facial pressure, sleep disturbance, and nasal discharge. It is estimated that approximately 107 million people in China suffer from chronic sinusitis, with about one-third having CRSwNP.
Up to 80% of patients with CRSwNP have type 2 inflammation, which is associated with more severe disease and nasal polyp recurrence. Interleukin-5 (IL-5) is a key cytokine driving this type 2 inflammation and is present at high levels in nasal polyp tissue. While surgery can remove polyps, the underlying type 2 inflammation often leads to their regrowth.
Mepolizumab: A Targeted Approach
Mepolizumab is a monoclonal antibody that targets interleukin-5 (IL-5), a key messenger protein (cytokine) in type 2 inflammation. By binding to and inhibiting IL-5, mepolizumab reduces the production and survival of eosinophils, which are implicated in the inflammatory process of CRSwNP. Mepolizumab is already approved in China for severe eosinophilic asthma in adults and adolescents aged 12 years and older, as well as for adults with eosinophilic granulomatosis with polyangiitis.
