Astellas Takes Stake in Taysha for $50 Million and Option to License Two Gene Therapy Programs

Astellas Pharma and Taysha Gene Therapies announced a strategic investment to support the advancement of Taysha’s adeno-associated virus (AAV) gene therapy development programs for the treatment of Rett syndrome and GAN.

Photo: RA Session II, CEO at Taysha Gene Therapies

Under the terms of the agreement, Astellas will invest a total of $50 million to acquire 15 percent of the outstanding common stock of Taysha and to receive an exclusive option to license two of Taysha’s clinical stage programs: TSHA-102 for Rett syndrome and TSHA-120 for GAN. In addition, Taysha has granted Astellas certain rights related to any potential change of control of Taysha. Definitive agreements would be executed upon Astellas’ exercise of any such option, and any change of control transaction would require approval by Taysha’s stockholders.

The companies say the future options to potentially apply Astellas’ global R&D, manufacturing, and commercialization capabilities in gene therapy to Taysha’s AAV gene therapy development programs for genetic diseases of the central nervous system create the opportunity for the two companies to enhance the development of novel treatment options for patients with Rett syndrome and GAN, who have serious unmet medical needs.

“We believe this investment not only further validates the potential of our technology platform, but also reinforces the therapeutic and market opportunity of our two lead clinical assets,” said RA Session II, CEO at Taysha Gene Therapies.

Taysha develops intrathecally delivered AAV gene therapies for monogenic CNS diseases and has a promising pipeline, including TSHA-102, which is the first-and-only gene therapy in clinical development for Rett syndrome, and TSHA-120, which is in phase 1/2 development for the treatment of GAN and awaiting regulatory feedback.

TSHA-102 is a self-complementary intrathecally delivered AAV9 gene replacement therapy under development for the treatment of Rett syndrome, a severe genetic neurodevelopmental disorder caused by a mutation in the X-linked MECP2 gene essential for neuronal and synaptic function in the brain, primarily occurring in females, characterized by rapid developmental regression that leads to intellectual disabilities, loss of speech, loss of purposeful use of hands, loss of mobility, seizures, cardiac impairments and breathing issues.. TSHA-102 has received Orphan Drug and Rare Pediatric Disease designations from the U.S. Food and Drug Administration and Orphan Drug designation from the European Commission.

TSHA-120, an intrathecally dosed AAV9 gene replacement therapy delivering the gene gigaxonin for the treatment of GAN, is currently being evaluated in an ongoing phase 1/2 clinical trial. The disease is caused by loss-of-function mutations in the gene coding for gigaxonin, which results in dysregulation of intermediate filament turnover, an important structural component of the cell. Children with GAN present before the age of five with symptoms including unsteady gait, frequent falls, and motor weakness. Currently, there are no approved treatments for GAN, which results in death for patients in their late teens or early twenties. TSHA-120 has received Orphan Drug and Rare Pediatric Disease designations from FDA and Orphan Drug designation from the European Commission.

Astellas has been building its gene therapy capability following the acquisition of Audentes (now Astellas Gene Therapies, California) in January 2020 and the construction of a state-of-the-art commercial GMP manufacturing facility in North Carolina, which was opened in June of this year.

“Our goal is to bring new transformative treatment options to patients living with serious genetic diseases and limited treatment options,” said Naoki Okamura, chief strategy officer at Astellas. “Taysha is an industry leader in CNS gene therapies and this partnership fits strategically with our long-term vision of expanding Astellas’ gene therapy capabilities, allowing the company to impact the lives of a broader range of patients with urgent unmet medical needs.”

As part of Taysha’s agreement with Astellas in connection with its equity investment, Astellas will receive one board observer seat on Taysha’s Board of Directors, enabling Taysha to leverage Astellas’ gene therapy clinical and commercial expertise as Taysha advances TSHA-120 and TSHA-102.

Author: Rare Daily Staff