Taysha Raises $30M, Partners with UT Southwestern to Develop Gene Therapies for Rett, Other Disorders

Taysha Gene Therapies has raised $30 million and established a partnership with UT Southwestern Medical Center to expand its gene therapy program for neurological disorders caused by mutations in a single gene, called monogenic diseases, including Rett syndrome.

The funding will allow the company to expand its pipeline, currently comprised of 15 gene therapies and with options to include four novel gene therapy programs.

Taysha expects to file four investigational new drug applications, a requirement to start clinical trials in the U.S., by the end of 2021. These applications will include Rett syndrome. A first gene therapy candidate (TGTX-101) for GM2-Gangliosidosis, a rare disorder that affects the central nervous system (CNS, brain and spinal cord), is scheduled to start clinical studies this year.

“Gene therapies have proven to deliver transformational benefit to patients who suffer from devastating diseases with significant, unmet medical need. Our mission at Taysha is to build upon these advancements to eradicate monogenic CNS diseases for the thousands affected,” R.A. Session II, PhD, president, CEO and founder of Taysha, said in a press release.

The partnership with UT Southwestern Gene Therapy Program, along with its Department of Pediatrics, will speed the development of novel gene therapies to be tested in preclinical and clinical development programs.

Such therapies use adeno-associated virus (AAV), a naturally occurring virus modified to work as an effective and safe gene therapy delivery vehicle. In the case of Rett syndrome, Taysha is developing a so-called gene replacement therapy known as TGTX-114. Notably, almost all classic Rett cases are caused by mutations in the MECP2 gene, which provides instructions to make a key protein for normal brain function.

UT Southwestern, in Dallas, has a state-of-the-art viral vector manufacturing facility that follows Good Manufacturing Practices (GMP), Taysha said. The program is led by Steven Gray, PhD, director of the Viral Vector Core and an associate professor in the Department of Pediatrics, along with Berge Minassian, MD, chief of the Division of Child Neurology.

Under the collaboration, UT Southwestern is responsible for the discovery and preclinical research of gene therapies. Also, it will lead natural history studies and research to support future clinical trials.

Taysha will lead clinical development, regulatory affairs and commercial activities. Key members of Taysha and UT Southwestern compose a joint steering committee that will foresee the collaboration.

“In joining forces with UT Southwestern — home to some of the brightest minds in gene therapy — we will advance our deep pipeline of potentially curative medicines with speed and scale,” said RA Session II, president, CEO and founder of Taysha. “At Taysha, we are ushering in a new era of gene therapy drug development, one in which we can rapidly translate early discoveries into the clinic and beyond.”

Claire Aldridge, PhD, associate vice president of commercialization and business development at UT Southwestern Medical Center and Taysha board member added: “In a short amount of time, I’ve already witnessed how quickly and efficiently we can leverage our collective expertise and resources to advance new gene therapies to the patients who so desperately need them.”

The $30 million seed funding was co-led by PBM Capital, AveXis (a Novartis-owned company) and Nolan Capital, the investment fund of former AveXis CEO Sean Nolan. Nolan is now chairman of Taysha’s board of directors, which includes Paul Manning of PBM Capital, Aldridge, and Session.

The company’s approach focuses on developing a novel AAV capsid (the protein shell of a virus) using machine learning and other methods. Taysha  also is working to enable gene therapy re-dosing by avoiding immune response through delivery to the vagus nerve — a long nerve running from the brain to the abdomen.

“Taysha is leveraging the proven safety and heritage of AAV technology—combining it with an experienced management team and the world-class capabilities of UT Southwestern — to rapidly accelerate the research and development of multiple new therapies at a scope we haven’t seen before,” said Nolan. “This is an exciting time for gene therapy, and Taysha’s approach brings promise to patients suffering from many devastating CNS diseases.”