The U.S. Food and Drug Administration (FDA) has granted accelerated approval to KEBILIDI (eladocagene exuparvovec), a gene therapy developed by PTC Therapeutics, for the treatment of aromatic L-amino acid decarboxylase (AADC) deficiency. This marks the first gene therapy in the U.S. that is directly delivered to the brain, offering a new treatment option for children and adults affected by this rare and debilitating genetic disorder.
Mechanism of Action and Clinical Efficacy
KEBILIDI utilizes a recombinant adeno-associated virus serotype 2 (AAV2) vector to deliver a functional DOPA decarboxylase (DDC) gene directly into the putamen of the brain. AADC deficiency results from mutations in the DDC gene, leading to a deficiency in the AADC enzyme, which is crucial for dopamine synthesis. By delivering a functional copy of the DDC gene, KEBILIDI aims to restore dopamine production in the brain.
The FDA's accelerated approval was based on data from the ongoing PTC-AADC-GT-002 global clinical trial. Results from these trials have demonstrated promising outcomes, including the de novo synthesis of dopamine and subsequent achievement of motor development milestones in treated patients. These milestones are significant, as AADC deficiency severely impairs motor function due to the lack of dopamine, an essential neurotransmitter.
AADC Deficiency: An Unmet Medical Need
AADC deficiency is a rare genetic disorder that profoundly affects motor function and overall development. The condition prevents the synthesis of dopamine and serotonin, critical neurotransmitters in the brain. This deficiency leads to severe motor impairments, developmental delays, and other neurological symptoms. Currently, treatment options are limited, and there is a significant unmet need for therapies that address the underlying cause of the disease.
Launch and Future Plans
PTC Therapeutics is actively preparing for the launch of KEBILIDI in the U.S. This includes the identification of centers of excellence and the training of surgeons to perform the precise neurosurgical procedure required for the administration of the gene therapy. According to PTC Therapeutics CEO Matthew Klein, this approval marks a pioneering step in treating highly morbid neurologic diseases, reflecting the company's commitment to bringing transformative therapies to patients with significant unmet needs.
As part of the biologics license application approval, PTC Therapeutics has also been awarded a rare disease priority review voucher, which the company intends to monetize. In October 2022, PTC Therapeutics secured a strategic financing partnership with Blackstone, valued at up to $1 billion, to support the development of its product pipeline, further enabling the advancement of innovative therapies like KEBILIDI.
