The FDA expanded Joenja (leniolisib) approval to children aged 4 to 11 with APDS weighing at least 27 kg, with doses expected in October.
Written By: Dishali Desai, PharmD
Reviewed By: Pharmacally Editorial Team
Pharming has secured U.S. FDA approval to expand Joenja (leniolisib) to children aged 4 to 11 years with activated phosphoinositide 3-kinase delta syndrome (APDS) who weigh at least 27 kg, making it the first FDA-approved treatment for this pediatric population. The newly approved 40 mg and 50 mg twice-daily doses are expected to become available in the U.S. in October.
FDA Expands Joenja’s Pediatric Reach
The supplemental New Drug Application (sNDA) approval extends Joenja, an oral selective PI3Kδ inhibitor, to younger children with APDS. The drug was initially approved by the FDA in March 2023 for adults and children aged 12 years and older.
Pharming submitted the latest application based on data from a multinational, open-label, single-arm Phase III study involving children aged 4 to 11 years with APDS. The company is also pursuing lower doses for children weighing 13 kg to less than 27 kg, with a separate sNDA submitted on July 30.
Targeting the Underlying Immune Defect
APDS is a rare primary immunodeficiency caused by activating variants in either PIK3CD or PIK3R1, which disrupt normal immune-cell development and function. Excessive PI3Kδ pathway activity contributes to immune dysregulation, recurrent sinopulmonary infections, lymphoproliferation, autoimmunity and enteropathy.
The disease often begins in early childhood and can progress to permanent lung damage and lymphoma. Because its symptoms overlap with other immune disorders, patients can face substantial diagnostic delays, with a reported median delay of seven years.
Leniolisib selectively inhibits PI3Kδ and reduces production of phosphatidylinositol-3-4-5-trisphosphate, a signaling molecule involved in immune-cell proliferation, differentiation, survival and other cellular functions. By suppressing excessive PI3Kδ signaling, the drug addresses a central molecular driver of APDS rather than treating only its clinical manifestations.
Phase III Data Supported the Expansion
In the pediatric Phase III study, treatment with leniolisib produced improvements over 12 weeks in two clinically relevant measures of APDS: reduced lymphadenopathy and increased naïve B-cell levels. Together, the findings indicated improvement in the underlying immune defect associated with the disease.
The safety profile remained consistent with previous Joenja experience. All treatment-emergent adverse events reported in the study were mild to moderate, and no drug-related serious adverse events occurred.
In the broader Joenja safety population, neutropenia has been observed. Among patients aged 12 years and older, seven of 21 patients developed an absolute neutrophil count (ANC) between 500 and 1,500 cells/µL. Among the pediatric patients aged 4 to 12 years weighing at least 27 kg, five of eight experienced ANC in that range. No patient developed an ANC below 500 cells/µL, and no infections were associated with neutropenia.
Earlier Treatment Could Change Disease Management
Eveline Wu, M.D., MSCR, associate professor of pediatrics at the University of North Carolina at Chapel Hill, emphasized that earlier intervention could address APDS before progressive immune dysfunction causes irreversible complications.
The approval also gives physicians an option to intervene earlier in the disease course, when recurrent infections and immune dysregulation can interfere with schooling, social development and everyday activities.
October Launch Planned as Lower-Dose Review Continues
Pharming expects the newly approved Joenja doses to reach eligible U.S. pediatric patients in October through its existing specialty distribution and patient-support infrastructure.
The company is continuing its regulatory work for children weighing 13 kg to less than 27 kg. Joenja is already approved in several other markets for older pediatric and adult patients, while regulatory review for APDS continues in Canada and other countries.
The FDA expansion therefore broadens access to the first approved targeted treatment for younger U.S. patients with APDS, while the pending lower-weight application could extend treatment to an even wider pediatric population.
Reference
FDA approves Pharming’s Joenja® as first treatment for children with APDS in the U.S., Pharming Group, 11 SEPTEMBER 2026
About the Writer
Dishali Desai (LinkedIn) is a PharmD professional with expertise in clinical pharmacy, evidence-based healthcare writing, and published work on Brugada syndrome and ADR reporting.
Her interests include guideline integration, multimodal therapy, pharmacogenomics, and antibiogram utilization, with a focus on clinical evidence and treatment decisions.
As a healthcare writer, she translates complex clinical information into clear, accurate, and evidence-informed medical content.