Pharming secures MHRA approval for Joenja (leniolisib) in children aged 4–11 years with APDS weighing at least 27 kg, with UK availability expected in February 2027.
Written By: Kalyani Boharapi, M. Pharm (RA)
Reviewed By: Pharmacally Editorial Team
Pharming Group N.V. announced on November 6, 2026, that the UK Medicines and Healthcare products Regulatory Agency (MHRA) has approved an extension of the marketing authorization for Joenja (leniolisib) to include children aged 4–11 years weighing at least 27 kg with activated phosphoinositide 3-kinase delta (APDS) syndrome. The decision makes Joenja the first treatment specifically approved in the UK for children with APDS in this age group. The expanded indication covers 40 mg and 50 mg twice-daily dosing regimens, with UK commercial availability expected in February 2027.
MHRA Expands Joenja’s Existing Indication to Younger Children
The approval expands Joenja’s existing UK authorization, which previously covered eligible adults and adolescents aged 12 years and older. The newly authorized paediatric population includes children aged 4–11 years weighing at least 27 kg. Pharming will work in coordination with the National Health Service (NHS) and relevant healthcare stakeholders to support access for eligible patients following this decision.
The regulatory decision was supported by data from the company’s dedicated paediatric clinical development programme, conducted under an MHRA-agreed Paediatric Investigation Plan (PIP), alongside additional clinical pharmacology and safety assessments supporting the approved dosing regimen. Leniolisib was generally well tolerated in patients aged 4 years and older, supporting the company’s assessment of a favorable benefit-risk profile in this population.
APDS Etiology and Rationale for Targeted PI3Kδ Inhibition
APDS is a rare primary immunodeficiency caused by pathogenic variants in either the PIK3CD or PIK3R1 gene. These genetic alterations lead to hyperactivation of the phosphoinositide 3-kinase delta (PI3K$\delta$) signalling pathway, disrupting normal immune-cell development and function.
The condition is characterized by recurrent sinopulmonary infections, lymphoproliferation, autoimmunity, and enteropathy. APDS affects approximately 1 to 2 individuals per million worldwide and inflicts a substantial disease burden starting in early childhood.
Leniolisib is an oral, selective PI3K$\delta$ inhibitor that reduces the hyperactive generation of phosphatidylinositol-3,4,5-trisphosphate (), a key intracellular signalling lipid involved in immune-cell proliferation, differentiation, cytokine production, and cell survival. By directly inhibiting dysregulated PI3K$\delta$ activity, leniolisib targets the underlying molecular mechanism driving APDS-associated immune dysfunction.
Clinical Evidence Base
The broader clinical development program for leniolisib includes a randomized, placebo-controlled Phase 3 trial that demonstrated statistically significant improvements in its coprimary endpoints, establishing initial clinical efficacy in APDS, with long-term open-label extension data providing continued safety profiling.
However, the specific label expansion for children aged 4–11 years was supported by the dedicated paediatric development program together with targeted clinical pharmacology and safety evaluations. Distinguishing between the pivotal Phase 3 study in older populations and the paediatric PIP framework reflects the distinct clinical components contributing to the drug’s overall profile.
Regulatory and Clinical Significance
The MHRA decision addresses a significant therapeutic gap for younger children with APDS in the UK who previously lacked targeted treatment options. Rather than introducing a novel therapeutic class, this decision broadens access to an established targeted therapy, demonstrating the utility of dedicated paediatric investigation plans in expanding care for rare genetic immunodeficiencies. Pharming’s targeted availability timeline of February 2027 marks the next key operational step toward commercial and NHS patient access in the UK.
Reference
MHRA approves Pharming’s Joenja® (leniolisib) as first treatment specifically for children with APDS in the U.K., Pharming, 06 November 2026
About the Writer
Kalyani Boharapi (LinkedIn) is a pharmacy professional and healthcare writer currently pursuing an M.Pharm in Regulatory Affairs at Dr. D. Y. Patil College of Pharmacy, with interests in pharmaceutical regulations, drug development, and healthcare innovation. She has academic exposure to dossier preparation, scientific writing, and regulatory documentation. Kalyani has also completed certification courses in Generative AI, AI in Pharma, and Bioinformatics, and actively participates in pharmaceutical conferences to stay updated with emerging trends and advancements in the healthcare and pharmaceutical industry.