PTC Seeks Marketing Authorization for its AADC Gene Therapy in Europe

Ana Pena, PhD avatar

by Ana Pena, PhD |

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PTC Therapeutics is seeking approval of PTC-AADC, a gene therapy candidate to treat aromatic l-amino acid decarboxylase (AADC) deficiency, from the European Medicines Agency (EMA), the company announced in a corporate update.

Its application is among the highlights from 2019 that the company will present at the 38th Annual J.P. Morgan Healthcare Conference, held this week in California.

An opinion by the Committee for Medicinal Products for Human Use — the EMA branch responsible for evaluating and issuing an opinion about EU-wide approval requests for new medicinal products — is expected in the second half of 2020.

PTC Therapeutics says it will soon request marketing approval for PTC-AADC in the U.S. The company wanted to file a Biologics License Application to the U.S. Food and Drug Administration by the end of 2019, but the agency asked for additional information about the therapy’s commercial delivery for children, postponing the application to the second quarter of 2020.

According to the update, the company has identified 200 AADC patients who are in a condition to receive the commercial version of PTC-AADC, and expects that number to grow to more than 300 by the time the product reaches the market.

Gene therapy is the treatment of genetic diseases through the delivery of corrective “therapeutic DNA” into patient’s cells. PTC-AADC (formerly AGIL-AADC) is a candidate gene therapy designed to deliver a healthy copy of the DDC gene — the faulty gene in patients with AADC deficiency — into the patient’s nerve cells, or neurons, in the brain.

A working copy of DDC is passed on to cells through an adeno-associated virus (AAV) that is modified to be harmless. The goal is to increase the production of the AADC enzyme, which is missing in patients due to their genetic defect, and counter the symptoms caused by this deficiency.

The treatment is injected via a surgical procedure into an area of the brain called the putamen. This region is fundamental for the production of neurotransmitters (chemicals that relay messages from neurons) such as dopamine and serotonin, which fail to be produced in patients because their neurons lack a functional AADC enzyme.

Recently, PTC Therapeutics presented clinical trial results at the 48th Annual Meeting of the Child Neurology Society, demonstrating that one-time treatment of children with AADC deficiency with PTC-AADC lowered the number of oculogyric crises (involuntary upward eye movement), recovered children’s weight, and improved their ability to sit, walk, and talk over a five-year period.

Additional analysis found that the therapy’s benefits can hold up to five years after treatment.

The data came from three open-label clinical trials, which together enrolled 26 children with AADC deficiency, ranging in age from 21 months to 8.5 years.

To control and accelerate its gene therapy pipeline — which includes a therapy candidate for Friedreich’s ataxia — PTC Therapeutics rented an additional 185,000 sq. ft. of space in New Jersey, which includes a biologics production facility together with supporting research and operations buildings. The company believes the first products will start to be manufactured at this facility this year.

According to preliminary financial estimates, PTC Therapeutics expects to report 2019 year-end cash and cash equivalents of approximately $686 million.