Pharming wins FDA approval for Joenja in children aged 4 to 11 with APDS
Pharming has received FDA approval for an expanded paediatric indication for Joenja (leniolisib), covering children aged 4 to 11 years who weigh at least 27 kg and carry a diagnosis of activated phosphoinositide 3-kinase delta syndrome (APDS). The approval, granted via a supplemental New Drug Application, makes Joenja the first and only therapy licensed by the FDA for this younger patient group.
Joenja was originally approved in the United States in March 2023 for adults and paediatric patients aged 12 and older. The newly approved 40 mg and 50 mg twice-daily doses are expected to be commercially available through Pharming's existing specialty distribution network from October 2026.
The clinical evidence
The supplemental approval is supported by data from a multinational, open-label, single-arm Phase 3 study in children aged 4 to 11 years. Over a 12-week treatment period, the study recorded improvements in two clinically relevant markers of the condition: reduced lymphadenopathy and an increase in naïve B cells, both of which are indicative of improvement in the underlying immune defect. The safety profile seen in the paediatric cohort was consistent with prior leniolisib experience. All treatment-emergent adverse events were mild to moderate; no drug-related serious adverse events were observed. Neutrophil count reductions were observed in a proportion of patients, though no patient fell below the threshold associated with infection risk.
Eveline Wu, Associate Professor of Paediatrics at the University of North Carolina at Chapel Hill, said the approval allows clinicians to "address the underlying pathway of disease, with the goal of reducing symptoms and preventing the irreversible complications that often arise with APDS," rather than relying solely on symptomatic management.
Pharming has also filed a further sNDA, submitted in July 2026, seeking approval of lower doses for children in the same age band who weigh between 13 kg and less than 27 kg. That application, if approved, would extend access to the lightest children in the target age group.
Market context and competitive landscape
APDS is among the rarest of the characterised primary immunodeficiencies, affecting an estimated one to two people per million globally and first fully characterised in 2013. The condition is caused by gain-of-function variants in either the PIK3CD or PIK3R1 genes, leading to hyperactivity of the PI3K-delta pathway and consequent failure of immune-cell maturation. A median diagnostic delay of seven years has been reported in the literature, meaning many children accumulate irreversible lung damage before treatment begins. The approval therefore carries particular clinical urgency, because PI3K-delta inhibition is a mechanism that acts on disease biology rather than downstream complications.
Pharming holds an enviable position in the APDS market as the only company with an approved product for the condition in the US, EU, UK, Canada, Australia, Israel and Japan. A small number of early-stage programmes are in development for related primary immunodeficiencies, but no licensed competitor has yet entered the APDS space. The PI3K-delta inhibitor class is well established in oncology, where several agents have been approved for B-cell malignancies; regulatory and clinical familiarity with the mechanism may work in Pharming's favour as it pursues further label expansions. Leniolisib is also in two Phase 2 trials evaluating it in broader primary immunodeficiencies with immune dysregulation, which could open additional indications over the medium term.