Pharming Group N.V. announced that it has received a positive decision from the UK'sMedicines and Healthcare Products Regulatory Agency (MHRA) on a Paediatric Investigation Plan (PIP) submission for leniolisib, an oral, selective phosphoinositide 3-kinase delta (PI3K) inhibitor, for the treatment of activated phosphoinositide 3-kinase delta syndrome (APDS) in patients from 1 year of age to less than 18 years of age. The Company also announces that the MHRA has granted Promising Innovative Medicine (PIM) designation to leniolisib for the treatment of APDS. A PIP is a development plan aimed at ensuring that the necessary data are obtained to support the marketing authorization of a medicine in the pediatric population.

All applications for marketing authorization for new medicines in children require the results of studies as described in an agreed PIP, unless the medicine is exempt due to a deferral or waiver. The leniolisib PIP includes two planned global clinical trials in pediatric patients with APDS, the first in children ages 4-11 years and the second in children ages 1-6 years. The Company expects to initiate recruitment for this pediatric program for leniolisib during the second half of 2022.

A PIM designation indicates that a medicinal product is a promising candidate for the MHRA's Early Access to Medicines Scheme (EAMS), which provides pre-market access to products that are intended for the treatment, diagnosis, or prevention of a life-threatening or seriously debilitating condition and have the potential to address an unmet medical need. As previously announced, Pharming plans to begin submitting global registration filings for leniolisib in the second quarter of 2022 and, subject to approval, launching the treatment in the U.S. in the first quarter of 2023 and starting a series of European launches in the second half of 2023. About Activated Phosphoinositide 3-Kinase Syndrome (APDS) APDS is a rare primary immunodeficiency that affects approximately one to two people per million.

Also known as PASLI, it is caused by variants in either of two genes, PIK3CD or PIK3R1, that regulate maturation of white blood cells. Variants of these genes lead to hyperactivity of the PI3K (phosphoinositide 3-kinase delta) pathway.(1,2) Balanced signaling in the PI3K pathway is essential for physiological immune function. When this pathway is hyperactive, immune cells fail to mature and function properly, leading to immunodeficiency and dysregulation.(1,3) APDS is characterized by severe, recurrent sinopulmonary infections, lymphoproliferation, autoimmunity, and enteropathy.(4,5) Because these symptoms can be associated with a variety of conditions, including other primary immunodeficiencies, people with APDS are frequently misdiagnosed and suffer a median 7-year diagnostic delay.(6) As APDS is a progressive disease, this delay may lead to an accumulation of damage over time, including permanent lung damage and lymphoma.(4-7) The only way to definitively diagnose this condition is through genetic testing.