Leniolisib

October 14, 2026: Pharming (NASDAQ: PHAR) presented positive topline Phase II data for leniolisib in 13 patients with genetically identifiable primary immunodeficiencies with immune dysregulation linked to altered PI3Kδ signaling, in a late-breaking poster at the ESID meeting (October 14-17, 2026).

The single-arm, open-label, intra-patient dose-escalation study enrolled patients with CTLA4, SOCS1, NFKB1, or FAS variants; 9 of 13 also had common variable immunodeficiency (CVID). Over 20 weeks, leniolisib was generally well tolerated, with no new safety signals; infections were the most common adverse events, all treatment-related AEs were Grade 1, two serious AEs were unrelated, and one patient discontinued early due to acute hepatitis in the setting of prior portal hypertension.

Topline efficacy signals included a 26.4% mean reduction in spleen volume (10/11 improved), a 33.7% mean reduction in lymph node index lesion size (4/4 improved), an 8.0% mean increase in percent predicted DLCO among 7 patients with impaired baseline gas exchange, decreased CT-assessed interstitial lung disease scores in 4/5 evaluable patients, and improved liver stiffness in 2/3 patients with elevated baseline stiffness. All 12 completers entered a three-year extension study (NCT06990529).

Pharming also said topline results from a separate Phase II trial in CVID are expected in November and will inform plans for a potential registrational study in broader CVID.