Overview

• Mary Catchpole, 19, received leniolisib (Joenja) through the NHS in June 2025 as the first European patient treated for activated PI3-Kinase delta syndrome.
• Activated PI3-Kinase delta syndrome severely weakens the immune system by overactivating a key enzyme, leaving patients prone to recurring infections and dependent on lifelong antibiotics and immunoglobulin replacement.
• Leniolisib inhibits the PI3-Kinase delta enzyme to normalize immune responses, with ongoing therapy expected to sustain its benefits.
• The annual list price of £352,000 per patient has been reduced through a negotiated discount agreement between NHS England and Pharming.
• Researchers at the University of Cambridge and Addenbrooke’s Hospital are exploring leniolisib’s potential application in more common immune disorders.