Pharming Group N.V. ("Pharming" or "the Company") (EURONEXT Amsterdam: PHARM/Nasdaq: PHAR) announces that the first patient has been enrolled in its Phase III clinical trial in Japan evaluating leniolisib for the treatment of activated phosphoinositide 3-kinase delta syndrome (APDS) in adult and pediatric patients 12 years of age and older.

Pharming's single-arm, open-label clinical trial will evaluate the safety, tolerability, and efficacy of leniolisib in three patients 12 years of age and older who have a confirmed APDS diagnosis. Each patient will receive weight-based dosing up to 70mg of leniolisib twice daily for 12 weeks. The study's primary efficacy endpoints and secondary endpoints mirror those used to evaluate the clinical outcomes in each of the leniolisib APDS trials.

Pharming plans to include data from the trial in a future registration application for the approval of leniolisib to be filed with Japan's Pharmaceuticals and Medical Devices Agency (PMDA). Eligible patients enrolled in the trial will continue to receive the investigational drug for at least one year through an open-label extension trial.

Hirokazu Kanegane, Professor of the Department of Child Health and Development, Tokyo Medical and Dental University, commented:
"The initiation of this clinical study is a positive step for the APDS community in Japan. With patients currently reliant on supportive treatments, the prospect of a disease-modifying treatment for this rare primary immunodeficiency could represent an exciting new treatment option for patients, their families, caregivers and their doctors in Japan." 

Anurag Relan, MD, MPH, Chief Medical Officer of Pharming, commented:
"Building on the success of our multinational Phase II/III study of leniolisib in patients with APDS 12 years of age and older, I am pleased to confirm the initiation of our Phase III trial supporting the same population in Japan. By conducting this study, Pharming's goal is to introduce an oral treatment option that has the potential to alter the course of disease for patients with APDS, a rare and progressive disease, in Japan. Following the FDA's recent approval of Joenja® in the U.S., we are working with regulatory authorities to expand access to this targeted treatment for patients across the globe through additional market authorizations." 

In May 2023, leniolisib was granted orphan drug designation (ODD) by the Ministry of Health, Labour and Welfare of Japan (MHLW) for the treatment of APDS. There is currently no approved therapy in Japan for this complex and progressive disease. 

The MHLW's ODD system promotes the research and development of investigational drugs designed to treat diseases associated with significant unmet medical need and which affect fewer than 50,000 patients across Japan. Investigational drugs granted ODD in Japan benefit from additional guidance and subsidies for research and development activities, consultation for clinical development, and priority review of marketing authorization applications.

Leniolisib received regulatory approval from the United States Food and Drug Administration (FDA) for the treatment of APDS in patients 12 years of age or older in March 2023 and was commercially launched under the brand name Joenja® in the U.S. in April 2023.