PTC-AS Gene Therapy Program Update

Quick Overview

PTC Therapeutics provided an update on their PTC-AS gene therapy program at the 2022 FAST Science Summit. PTC is a biopharmaceutical company focused on rare disorders. They have a diverse pipeline, but the focus of this update was on their gene therapy platform. They discussed the progress of their AS program, which is currently in preclinical studies to support safety and efficacy. They highlighted the complexity and time-consuming nature of gene therapy manufacturing, but mentioned that PTC has internalized their manufacturing processes. They presented data showing the distribution and stability of their gene therapy vector, as well as improvements in neuronal communication and behavior in animal models. PTC is currently conducting first in human enabling studies and refining their selection and route of administration for a future clinical trial. They have also established their own gene therapy manufacturing site. PTC is actively involved in supporting the Angelman Biomarkers and Outcome Measures Alliance. Overall, they are working towards bringing their AS gene therapy program to a first in human clinical trial while navigating the challenges of gene therapy.


Stephanie Ciarlone, on behalf of PTC Therapeutics, provides an update on the PTC-AS gene therapy program at the 2022 FAST Science Summit. PTC Therapeutics is a global biopharmaceutical company focused on developing innovative treatments for rare disorders. With over 1,300 employees and a presence in over 50 countries, PTC Therapeutics is committed to bringing new therapies to patients in need.

PTC Therapeutics Overview

PTC Therapeutics was founded in 1998 and has since grown significantly. The company’s corporate headquarters are located in New Jersey, with a gene therapy manufacturing site also in New Jersey and an international headquarters in Dublin. PTC Therapeutics has a diverse pipeline, including research in splicing molecules, oncology, and gene therapy.

Upstaza Approval

Upstaza, a disease-modifying treatment for AADC deficiency, has recently received marketing authorization from the European Commission and the MHRA in the UK. This marks the first approved treatment for AADC deficiency and the first marketed gene therapy product for direct infusion to the brain. PTC Therapeutics has gained valuable experience in navigating the complex gene therapy space through the development, regulatory, and commercialization processes of Upstaza.

PTC-AS Gene Therapy Program

The focus of the update is on the PTC-AS gene therapy program. Currently, the program is in the preclinical stage, conducting studies to support safety and efficacy before moving into first in human trials. The program aims to develop a gene replacement therapy for AS (Angelman syndrome).

Challenges in Gene Therapy Manufacturing

Manufacturing gene therapies is a complex process that requires careful consideration and can be time-consuming. Compared to small molecule manufacturing, gene therapy manufacturing is more intricate and can take longer. External vendors can further extend the timeline. PTC Therapeutics has internalized its gene therapy manufacturing processes to have better control over timing and quality. The company’s gene therapy manufacturing site in Hopewell, New Jersey, plays a crucial role in the development and production of gene therapies.

Data and Findings

PTC Therapeutics has conducted studies on the PTC-AS vector to assess its distribution and expression in the brain. The vector showed dose-dependent increases in multiple brain regions, indicating widespread distribution. The expression of UBE3A, a protein involved in AS, was observed in the rodent brain following PTC-AS administration. The expression remained persistent and stable for at least six months post-injection.

The program also investigated the impact of PTC-AS on neuronal morphology and communication. The number of spines, which are crucial for neuronal communication, was significantly increased with higher doses of PTC-AS. This suggests a potential for improved neuronal communication.

Furthermore, PTC Therapeutics observed phenotypic changes and improvements in multiple domains in AS mice and rats treated with PTC-AS. These improvements were seen in neurologic health and function, motor function and learning, and synaptic plasticity. The data indicates the potential efficacy of PTC-AS in improving AS-related symptoms.

Current Status and Future Plans

PTC Therapeutics is currently conducting first in human enabling studies to demonstrate the safety and efficacy of PTC-AS. The company is refining the selection, route of administration, and targeted patient population for the first in human trial. While aiming for a homogeneous patient population, PTC Therapeutics is also considering the potential benefits of PTC-AS for other genotypes.

The company has established internal manufacturing processes for the clinical program at the PTC Therapeutic Center of Excellence for gene therapy in Hopewell, New Jersey. This facility is responsible for the development, testing, and manufacturing of gene therapies for clinical trials, including PTC-AS.

PTC Therapeutics is actively involved in the Angelman Biomarkers and Outcome Measures Alliance, supporting initiatives to advance research and improve outcomes for Angelman syndrome patients.

In conclusion, PTC Therapeutics is committed to advancing the PTC-AS gene therapy program safely and efficiently. The company aims to bring this therapy to a first in human clinical trial while navigating the complexities of the gene therapy field.

Talk details

  • Title: PTC-AS Gene Therapy Program Update
  • Author(s): Stephanie Ciarlone
  • Author(s)’ affiliation: PTC Therapeutics
  • Publication date: 2022-12-03
  • Collection: 2022 FAST Science Summit