FDA Approves PTC's Kebilidi As First Gene Therapy To Treat AADC Deficiency

(RTTNews) - The U.S. Food and Drug Administration approved PTC Therapeutics, Inc.'s Kebilidi (eladocagene exuparvovec-tneq) gene therapy for the treatment of aromatic L-amino acid decarboxylase or AADC deficiency. Kebilidi is the first FDA-approved gene therapy for the deficiency.

PTC shares gained around 8.5 percent in the extended trading on the Nasdaq on Thursday, at $45.97.

AADC deficiency is a rare genetic disorder that affects the production of some neurotransmitters, which are chemical messengers that allow cells in the body's nervous system to communicate with each other. The patients are likely to experience symptoms such as delays in gross motor function (head control, sitting, standing, and walking), hypotonia (weak muscle tone), and developmental and cognitive delays.

Kebilidi is an adeno-associated virus vector-based gene therapy indicated for the treatment of adult and pediatric patients with AADC deficiency. Kebilidi is administered through four infusions in one surgical session into a large structure in the brain involved in motor control.

The health regulator also authorized ClearPoint Neuro, Inc.'s SmartFlow Neuro Cannula, an infusion tube inserted into a target in the brain (parenchymal tissue), to deliver Kebilidi. It is currently the only FDA authorized device indicated for use to administer Kebilidi.

The FDA noted that Kebilidi should be administered in a medical center that specializes in pediatric stereotactic neurosurgery, a technique that uses imaging and special equipment to deliver therapies to specific areas in the brain.

The treatment with Kebilidi results in the expression of AADC and subsequent increase in the production of dopamine, a critical neurotransmitter in the brain associated with movement, attention, learning and memory.

The approval was based on an open-label, single-arm clinical study in 13 pediatric patients with confirmed diagnosis of AADC deficiency, which showed the safety and effectiveness of Kebilidi.

Kebilidi's most common adverse reactions include dyskinesia (involuntary muscle movements), fever, low blood pressure, anemia (low red blood cell count), increased saliva production, and insomnia, among others. It is also contraindicated in patients who have not achieved skull maturity assessed by neuroimaging.

The application earlier was granted FDA's Priority Review and Orphan Drug designation, as well as a rare pediatric disease priority review voucher.

The FDA approved Kebilidi using the Accelerated Approval pathway, which allows the agency to approve certain products for serious or life-threatening conditions based on evidence of a product's effect on a surrogate endpoint or an intermediate clinical endpoint that is reasonably likely to predict clinical benefit.

A confirmatory trial is ongoing to verify Kebilidi's clinical benefit.

Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said, "Clinical advancements in the field of gene therapy continue to lead to the discovery and availability of innovative treatment options for rare diseases that are otherwise difficult to manage. Today's approval underscores our commitment to help make safe and effective treatments available for patients in need."