Astellas Pharma has agreed to acquire a stake of 15% in Taysha Gene Therapies, a US-based biotech company, for $50m in a move to support the development of the latter’s adeno-associated virus (AAV) based gene therapy programmes.

Taysha Gene Therapies’ gene therapies are focussed on the treatment of Rett syndrome and giant axonal neuropathy (GAN).

Taysha Gene Therapies CEO RA Session II said: “We are excited to enter this strategic investment with Astellas, a premier biopharmaceutical company with global R&D, manufacturing and commercial capabilities.

“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.”

As per the terms of the agreement, Astellas Pharma will obtain an exclusive option to license the US firm’s TSHA-102 for Rett syndrome and TSHA-120 for GAN. Both the gene therapy candidates are in clinical development.

Additionally, the Japanese pharma company has been granted certain rights associated with any possible change of control of Taysha Gene Therapies, which is listed on NASDAQ. Definitive agreements will be signed after Astellas Pharma exercising any such option, and any change of control deal will need approval by the US firm’s stockholders.

Taysha Gene Therapies is expected to make use of Astellas Pharma’s clinical and commercial expertise in gene therapies as the company advances TSHA-120 and TSHA-102.

The Japanese pharma company acquired biotech company Audentes for $3bn in January 2020 and followed it up with the construction of a commercial GMP manufacturing plant in North Carolina, which was opened earlier this year.

Astellas Pharma chief strategy officer Naoki Okamura said: “Gene therapy is the corner stone of Astellas’ Primary Focus, Genetic Regulation; our goal is to bring new transformative treatment options to patients living with serious genetic diseases and limited treatment options.

“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.”