Pharming: leniolisib demonstrates positive Phase II results beyond APDS
On September 22, 2026, Pharming announced the acceptance of a late-breaking abstract presenting preliminary positive data from a Phase II trial conducted with leniolisib in patients with primary immunodeficiencies (PID) associated with immune dysregulation linked to PI3Kδ signaling.
The Dutch group is thus expanding the evaluation scope of a molecule currently approved for a single syndrome (APDS) toward a potentially larger patient population. A second milestone is expected in the fourth quarter of 2026.
Average reduction of 26.4% in splenic volume in 13 patients
The trial is a Phase II open-label, single-arm study with intra-patient dose escalation, evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of leniolisib in 13 subjects with genetically defined PID.
According to Pharming, clinical results include improvement in lymphoproliferative disease, with an average 26.4% reduction in spleen volume and a decrease in index lesion size. The safety profile observed remained consistent with the known profile of the molecule, with infections being the most frequent events, with no new safety signal identified.
Expansion of evaluation scope beyond APDS syndrome alone
Leniolisib is an oral phosphoinositide 3-kinase delta inhibitor, approved as the first and only targeted treatment for APDS syndrome in adults and children in several countries, including the United States, the United Kingdom, the European Union, Canada, Japan, and South Korea.
These new data focus on PID beyond APDS, a scope for which the safety and efficacy of the molecule have not yet been established. Among the 13 patients enrolled, nine also had a diagnosis of common variable immunodeficiency (CVID).
According to Anurag Relan, Medical Director at Pharming, these results represent a step in evaluating the potential of leniolisib to treat immune dysregulation in PID beyond APDS, with the prospect of a substantially larger patient population. Additional data will be presented at the ESID 2026 congress, which will be held from October 14 to 17 in the Netherlands.
Phase II results in CVID expected in the fourth quarter of 2026
Pharming plans to communicate, in the fourth quarter of 2026, Phase II results of leniolisib in patients with CVID with immune dysregulation, with or without an identified genetic cause.
According to management, these results will guide its plans for a potential registration study in the broader CVID population. This timeline extends a year marked commercially by the 37% increase in Joenja revenues in the first half of 2026 and by European marketing authorization for this product obtained on May 22, 2026, according to information published on July 30, 2026.
