Joenja Approved for Activated Phosphoinositide 3-Kinase Delta Syndrome

The Food and Drug Administration (FDA) has approved Joenja^® (leniolisib) for the treatment of activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS) in patients 12 years of age and older.

APDS is a rare primary immunodeficiency caused by variants in either the PIK3CD or PIK3R1 genes, which are important to the development and function of white blood cells. Variants of these genes lead to hyperactivity of the phosphoinositide 3-kinase delta (PI3Kδ) pathway resulting in immunodeficiency and dysregulation. Leniolisib is an oral, selective PI3Kδ inhibitor.

The approval was based on data from a phase 2/3 trial (ClinicalTrials.gov Identifier: NCT02435173) evaluating the efficacy and safety of leniolisib in patients 12 years of age and older with APDS. Patients were randomly assigned 2:1 to receive either Joenja 70mg (n=21) or placebo (n=10) twice a day for 12 weeks. The coprimary efficacy endpoints were improvement in lymphoproliferation as measured by a change from baseline in lymphadenopathy measured by the log10-transformed sum of product diameters and the normalization of immunophenotype as measured by the percentage of naïve B cells out of total B cells.

Findings showed that leniolisib achieved a statistically significant reduction in index lymph node size (placebo-adjusted difference, -0.25; 95% CI, -0.38, -0.12; P =.0006) and for the percent improvement in naïve B cell counts (placebo-adjusted difference, 37.30; 95% CI, 24.06-50.54; P =.0002), compared with placebo.

As for safety, the most common adverse reactions (incidence greater than 10%) for leniolisib were headache, sinusitis, and atopic dermatitis. Leniolisib carries a risk for embryo-fetal toxicity and the pregnancy status of patients of reproductive potential should be verified prior to starting treatment.

The FDA previously granted Priority Review to leniolisib for this indication.

Dr. Eveline Wu, MD, MSCR, Division Chief, Paediatric Rheumatology & Associate Professor of Paediatric Rheumatology and Allergy/Immunology at The University of North Carolina School of Medicine, said: “The FDA approval of Joenja^® is an exciting moment for the APDS community and offers to transform the treatment pathway for patients and families affected by this rare disease. This approval means that they will, for the first time, have access to an approved treatment, which has the potential to change the standard of care for the patient population suffering from APDS.”

Joenja is supplied as 70mg tablets in 60-count bottles. The product is expected to be available in early April 2023.