The US FDA has approved a supplemental New Drug Application (sNDA) for Joenja (leniolisib), extending its indication to children aged 4 to 11 years weighing at least 27 kg with activated phosphoinositide 3-kinase delta syndrome (APDS), a rare primary immunodeficiency. The approval, granted to Netherlands-based Pharming Group (Euronext Amsterdam: PHARM / Nasdaq: PHAR), covers 40 mg and 50 mg twice-daily dosing and expands the existing label, which since March 2023 had covered adult and pediatric patients aged 12 years and older.
The approval follows a January 2026 Complete Response Letter in which the FDA raised concerns over potential underexposure in lower-weight children and requested additional information on an analytical method used for production batch testing. Pharming subsequently resubmitted the application for the 40 mg and 50 mg doses covering children weighing at least 27 kg.
Joenja is an oral, selective PI3Kδ inhibitor that blocks aberrant production of phosphatidylinositol-3,4,5-trisphosphate, a lipid messenger driving lymphocyte hyperactivation in APDS. By selectively targeting the PI3Kδ isoform — predominantly expressed in immune cells — leniolisib aims to restore more normal B and T cell differentiation without broadly suppressing other PI3K isoforms. The drug was originally synthesized by Novartis and in-licensed by Pharming; it is available in 40 mg, 50 mg, and 70 mg tablet formulations.
The sNDA was supported by a multinational, open-label, single-arm Phase III study enrolling children aged 4 to 11 years with APDS. Over 12 weeks, the study demonstrated improvements in two clinically relevant disease hallmarks — reduced lymphadenopathy and increased naïve B cells — indicating an effect on the underlying immune defect. All treatment-emergent adverse events were mild to moderate, and no drug-related serious adverse events were reported; the most common adverse reactions (incidence >10%) in this age group were abdominal pain, cough, and respiratory tract infection.