FDA delays Joenja® approval for younger children with rare immune disorder

Pharming Group has received a setback in its bid to expand the use of Joenja® (leniolisib) for younger children with a rare immune disorder. The US Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) for the drug's approval in patients aged 4 to 11. The decision does not affect Joenja's existing approval for those aged 12 and older.

Activated Phosphoinositide 3-Kinase Delta Syndrome (APDS) is a rare condition marked by severe infections, lymphoproliferation, and autoimmune complications. Currently, no approved treatments exist for children under 12 worldwide.

The FDA's letter highlighted two main concerns. First, it requested additional data on how the drug behaves in the bodies of younger, lower-weight children. Regulators worried about potential underexposure in this group. Second, the agency sought clarification on the analytical method used for testing production batches.

Despite the delay, Joenja has shown promise in clinical trials. A Phase III study in children aged 4 to 11 demonstrated improvements in two key disease markers. The drug, an oral PI3Kδ inhibitor, is already approved for APDS patients aged 12 and above.

Pharming Group, a biopharmaceutical company focused on rare diseases, has stated its intention to address the FDA's concerns. The firm plans to work closely with regulators to gather the required data and refine its testing methods. A resubmission timeline has not yet been announced.

The FDA's decision means Joenja will remain unavailable for children under 12 for now. Pharming must provide further pediatric pharmacokinetic data and revise its batch testing approach. Once resolved, the company can resubmit its application for this younger age group.