Mary Catchpole, a 19-year-old from Norfolk, has become the first patient in Europe to receive leniolisib (Joenja), a groundbreaking targeted treatment for activated PI3-kinase delta syndrome (APDS), following its approval by the NHS. The teenager, who lost four family members to this ultra-rare inherited immune disorder, received the life-changing medication at Addenbrooke's Hospital in Cambridge.
APDS affects between 40 to 50 people in England and leaves patients with severely compromised immune systems, making them vulnerable to recurrent infections and requiring lifelong antibiotic treatment and invasive medical procedures. Catchpole's family has been devastated by the condition—her mother Sarah died at 43 in 2018, her aunt Helen at 12, her uncle Edward at 39, and her grandmother Mary at 48.
Revolutionary Treatment Mechanism
Leniolisib represents the first targeted therapy for APDS, working by inhibiting an enzyme called PI3-kinase delta that remains "switched on" continuously in affected patients. This overactive enzyme disrupts white blood cell development and causes immune system dysregulation, leading to repeated lung infections, organ swelling, and increased risk of lymphoma.
The simple twice-daily tablet treatment effectively normalizes immune system function by blocking this problematic enzyme. Dr. Anita Chandra, consultant immunologist at Addenbrooke's Hospital and affiliated assistant professor at the University of Cambridge, described the drug as a "potential cure" for the condition.
"This new drug will make a huge difference to people living with APDS," said Dr. Chandra. "It is incredible to go from the discovery of a new disease in Cambridge to a treatment being approved and offered on the NHS within the space of 12 years."
From Discovery to Treatment
APDS was identified in 2013 by Cambridge researchers, with Catchpole's family playing a crucial role in its discovery. Her mother and uncle were Addenbrooke's patients who underwent DNA sequencing to identify potential genetic causes of their immunodeficiency. Researchers discovered genetic changes that increased PI3-kinase delta enzyme activity, preventing immune cells from effectively fighting infections.
Professor Sergey Nejentsev from the University of Cambridge, who led the research discovering APDS, explained: "As soon as we understood the cause of APDS, we immediately realised that certain drugs could be used to inhibit the enzyme that is activated in these patients. Leniolisib does precisely that. I am delighted that we finally have a treatment which will change the lives of APDS patients."
Patient Impact and Future Outlook
For Catchpole, who was diagnosed at age seven, the treatment represents a dramatic shift from a lifetime of medical interventions. She previously required permanent intravenous lines, regular hospital visits, and extensive medication regimens that prevented her from participating in physical activities and pursuing her passion for dance.
"I feel really blessed because it's so simple to do and it doesn't take up very much time, whereas for the medication, it just takes such a long time to do," Catchpole said. "It's really a blessing, but it's also obviously bittersweet because my late family members never got the chance to have it."
The teenager, who works as a teaching assistant, can now envision a future pursuing her dream of becoming a dance teacher and leading a more normal life. "I want to go on more adventures and take risks because all I've ever known is medication, needles, and hospital appointments, whereas now I can find out who I truly am," she said.
NHS Approval and Access
The NHS approved leniolisib following cost-effectiveness evaluation by NICE, despite its list price of £352,000 per year. Pharming, the drug manufacturer, agreed to a substantial confidential discount to make the treatment accessible through the NHS. NICE estimates the drug could benefit up to 50 patients over age 12 in England.
Professor James Palmer, NHS England's medical director for specialized commissioning, emphasized the significance of this approval: "This treatment could be life-changing for those affected by this debilitating genetic disorder, and this important step forward is another example of the NHS's commitment to offering access to innovative medicines for those living with rare conditions."
Patients eligible for leniolisib can be referred to Addenbrooke's Hospital for specialist review and care. Researchers are now exploring the potential for leniolisib to treat other, more common immune conditions, suggesting broader therapeutic applications may emerge from this breakthrough.
