In Japan, the regulatory submission for Nucala (mepolizumab) for chronic rhinosinusitis with nasal polyps was accepted for review by the Ministry of Health, Labour, and Welfare (MHLW). This development was announced by GSK, marking a significant step in potentially expanding the treatment options for adult patients dealing with chronic rhinosinusitis with nasal polyps (CRSwNP) in Japan.
The supplementary new drug application (sJNDA) is grounded in the findings of the pivotal phase III MERIT trial, which assessed the efficacy and safety of Nucala over 52 weeks in a diverse group of patients from Japan, China and Russia who had inadequately controlled CRSwNP or eosinophilic chronic rhinosinusitis (ECRS). Additionally, data from the global phase III SYNAPSE study, encompassing over 400 CRSwNP patients, were also considered in the submission.
CRSwNP/ECRS affects an estimated 2-4% of the general population. In Japan alone, approximately 2 million individuals suffer from chronic sinusitis, with around 200,000 facing the prospect of surgery due to nasal polyps. CRSwNP develops due to chronic inflammation of the nasal lining, with elevated levels of interleukin-5 (IL-5) contributing to this condition due to T2 inflammation. This can lead to soft tissue growth, known as nasal polyps, within the sinuses and nasal cavity. People with CRSwNP experience symptoms such as nasal obstruction, loss of smell, facial pressure, sleep disruption, and nasal discharge. Surgery may be recommended in severe cases, although polyps tend to recur, often necessitating repeat surgical interventions.
If Nucala receives approval, it will become the first anti-IL-5 biologic available for adult patients with inadequately controlled CRSwNP in Japan. Nucala is approved in Japan for bronchial asthma in children aged six and older, refractory asthma in adults with inadequate response to standard treatments, and for adult EGPA patients unresponsive to current therapies.
The MERIT trial's primary endpoints focused on changes in the total endoscopic nasal polyp score at week 52 from baseline and changes in the mean nasal obstruction VAS score over the four weeks preceding week 52. These co-primary endpoints were successfully met, with the efficacy and safety of mepolizumab in the Japanese population aligning with the results obtained from global trials.
In the United States, Nucala (mepolizumab) was initially approved in 2015 for treating severe eosinophilic asthma (SEA). It is a unique monoclonal antibody that targets and binds to interleukin-5 (IL-5), the primary cytokine responsible for eosinophil maturation and activation. The administration of mepolizumab has demonstrated its ability to reduce the number of blood eosinophils and maintain them within normal levels (defined as less than 500 eosinophils/microliter). Mepolizumab has been developed to address various IL-5-mediated diseases characterized by elevated blood eosinophil counts and has been subject to rigorous evaluation in over 4,000 patients across 41 clinical trials spanning multiple indications.