FDA rejects Pharming's rare disease drug for young children, citing key concerns

Pharming Group has received a setback from the U.S. Food and Drug Administration (FDA) over its drug Joenja® (leniolisib). The treatment, intended for children aged 4 to 11 with a rare immune disorder, was issued a Complete Response Letter (CRL). The company now faces additional requirements before resubmitting its application for approval.

Currently, no approved therapies exist for this age group anywhere in the world.

The FDA's letter highlighted two main concerns. First, it requested more pediatric pharmacokinetic data, particularly for lower-weight children, to ensure proper drug exposure. Second, it flagged an issue with the analytical method used for production batch testing.

Joenja®, an oral PI3Kδ inhibitor, was previously approved for patients aged 12 and older. In a Phase III study, the drug demonstrated improvements in key symptoms of Activated Phosphoinositide 3-Kinase Delta Syndrome (APDS), a rare condition marked by severe infections, autoimmune complications, and gastrointestinal issues. APDS affects roughly 1 to 2 people per million globally.

Pharming has stated it will collaborate closely with the FDA to address these concerns. The company aims to determine the next steps for resubmission while ensuring the existing approval for older patients remains unaffected.

The FDA's decision leaves children under 12 with APDS without an approved treatment option. Pharming's focus now shifts to gathering the required data and refining its testing methods. The outcome of these efforts will decide whether Joenja® can eventually reach this younger patient group.