Enrollment completed for trial of drug to treat children with rare primary immunodeficiency

08-Apr-2024 - Last updated on 08-Apr-2024 at 10:44 GMT

Pharming Group N.V. has declared the successful enrollment completion in its phase 3 clinical trial of leniolisib, an investigational drug designed for children aged 4 to 11 years with activated phosphoinositide 3-kinase delta syndrome (APDS).

Leniolisib, marketed as Joenja in the US, obtained FDA approval in March 2023 for treating APDS in adult and pediatric patients aged 12 and above. Pharming aims to incorporate data from this trial into global regulatory submissions for leniolisib's pediatric approval for APDS, starting in 2025.

Anurag Relan, chief medical officer of Pharming, said: “This is the first clinical trial for younger pediatric patients with APDS, who have a significant unmet need for a disease-modifying treatment. I am pleased with the progress made in our Phase III pediatric clinical program evaluating leniolisib in children with APDS.”

The trial enrolled 21 children with APDS aged 4 to 11 years across sites in the United States, Europe, and Japan. It is a single-arm, open-label study assessing leniolisib's safety, tolerability, and efficacy. Primary efficacy endpoints include reductions in index lymph node size and an increase in the proportion of naïve B cells from baseline at 12 weeks.

Secondary endpoints involve evaluating leniolisib's impact on health-related quality of life using a validated patient questionnaire. These endpoints align with previous leniolisib phase 2/3 trials for patients aged 12 and older.

The first patient received treatment in November 2023 in a separate phase 3 trial focusing on children aged 1 to 6 years with APDS, exploring a new pediatric formulation of leniolisib. Eligible patients from either trial will continue receiving leniolisib for a year beyond the initial 12-week period through an open-label extension study.

APDS, a rare primary immunodeficiency, is caused by variants in PIK3CD or PIK3R1 genes, leading to immune cell dysregulation. Symptoms include recurrent infections, lymphoproliferation, autoimmunity, and enteropathy. The diagnostic delay averages 7 years, contributing to progressive damage like permanent lung injury and lymphoma.

Leniolisib, an oral small molecule PI3Kẟ inhibitor, is the first targeted treatment for APDS approved in the U.S. Results from phase 2/3 trials showed its clinical efficacy in immune dysregulation, with interim data supporting long-term safety. Regulatory reviews are underway in various regions, including the European Economic Area and Japan, with ongoing phase 3 trials in children with APDS.