Pharming Group has announced that the European Commission (EC) has granted Marketing Authorization for Joenja (leniolisib), making it the first approved treatment in the European Union for Activated Phosphoinositide 3-Kinase Delta Syndrome (APDS), a rare primary immunodeficiency disorder.

The approval covers adult and paediatric patients aged 12 years and older living with APDS, a progressive genetic condition that affects immune system function and can significantly impact quality of life.

Joenja is an oral, selective Phosphoinositide 3-Kinase Delta (PI3Kδ) inhibitor designed to address the underlying disease mechanism associated with APDS. Following regulatory clearance, Pharming expects to begin its first European commercial launch in Germany during the third quarter of 2026, with additional European rollouts planned following national reimbursement processes.

According to Pharming, the approval marks a significant milestone for patients and healthcare providers in Europe, where therapeutic options for APDS have remained limited.

Leverne Marsh, Chief Commercial Officer at Pharming, said APDS can create long-term health challenges for patients and families, making access to targeted treatment approaches increasingly important.

He added that Joenja has the potential to reshape disease management by addressing underlying disease mechanisms rather than only treating symptoms.

The EC decision was supported by data from a multinational phase 2/3 clinical trial involving 31 patients aged 12 years and above diagnosed with APDS. The randomised, placebo-controlled and triple-blind study demonstrated statistically significant improvements in key markers related to immune dysregulation and immune deficiency.

Additional long-term evidence from an open-label extension study involving 37 patients receiving leniolisib for a median duration of three years further supported the therapy’s safety and effectiveness profile.

Ulrich Baumann, Managing Director and Consultant in Paediatric Immunology and Pulmonology at Hannover Medical School, Germany, said clinical evidence consistently demonstrated meaningful improvements in important immune function parameters among APDS patients treated with leniolisib. 

He noted that the medicine’s ability to directly target the biological mechanisms underlying APDS represents a significant advancement for a patient group that has historically faced limited treatment options.

The approval applies across all 27 European Union member states as well as Norway, Iceland and Liechtenstein.

Joenja is already approved in multiple international markets, including the United States, United Kingdom, Australia, Israel and Japan.

APDS was first identified in 2013 and is caused by genetic variants affecting immune cell development and function. The condition is linked to abnormalities in the PI3K delta pathway, resulting in immune dysregulation that can lead to recurrent infections, autoimmune complications, lymphoproliferation and gastrointestinal disease.

The disorder is estimated to affect approximately one to two individuals per million people globally.

Due to symptom overlap with other immune disorders, APDS patients often experience delayed diagnosis, with studies suggesting an average diagnostic delay of around seven years.

Experts note that delayed identification may contribute to progressive disease complications, including lung damage and increased lymphoma risk.

Leniolisib works by inhibiting PI3K delta signalling pathways involved in immune cell activity, aiming to improve immune regulation and reduce disease-related complications.

Beyond APDS, Pharming is evaluating leniolisib through ongoing phase 2 studies investigating broader immune dysregulation disorders, although its safety and efficacy outside APDS have not yet been established.

Pharming Group, headquartered in Leiden, the Netherlands, focuses on developing and commercialising therapies for rare, debilitating and life-threatening diseases, with operations across Europe and the United States.