Pictured: FDA sign in its headquarters/iStock, Grandbrothers

Taysha Gene Therapies has decided to drop its lead experimental AAV-based gene therapy candidate after the FDA reiterated calls for the company to put the treatment through a randomized, double-blind placebo-controlled trial.

The Dallas-based company announced on Tuesday that it would no longer be developing its TSHA-120 treatment for giant axonal neuropathy (GAN) based on the FDA’s Type C meeting feedback regarding the therapy’s potential pathway.

“FDA continues to recommend a randomized, double-blind, placebo-controlled trial as the optimal path to demonstrate efficacy in TSHA-120,” the company said in a statement.

Taysha noted in the announcement that the FDA “provided a potential path for a single-arm trial with an external control group matched with to-be treated patients by multiple prognostic factors and recommended longer term follow up to account for potential bias.”

CEO Sean Nolan said in a statement that the company plans “to pursue external strategic options for TSHA-120 that may enable further development of TSHA-120 and help patients with this devastating disease.”

GAN is an ultra-rare autosomal recessive disease of the central and peripheral nervous systems characterized by numbness and muscle weakness, which progress to seizures, loss of control over the body and gradual mental decline.

The company initially submitted Phase I/II data for the FDA’s review in 2022, with the agency coming back noting the need “to address the heterogeneity of disease progression in GAN and the effort-dependent nature of MFM32 as a primary endpoint in an unblinded study.”

Taysha followed up with a new comprehensive analysis that it presented in June 2023, with the FDA ultimately reiterating its previous feedback.

Meanwhile, Taysha is shifting gears after having to significantly trim its development pipeline since its initial public offering in September 2020, having gone from listing 18 programs in development across its portfolio down to just one—with another three including TSHA-120 available for external strategic deals. The remaining candidate, TSHA-102, is a potential treatment for Rett syndrome, a rare genetic neurological and developmental disorder.

“This strategic program prioritization is expected to extend our cash runway into the fourth quarter of 2025 to support the continued clinical development of TSHA-102 in Rett syndrome,” Nolan said. “We remain focused on continuing to evaluate the therapeutic potential of TSHA-102 in our ongoing REVEAL Phase 1/2 trial in adults and our planned pediatric trial.”

Tuesday’s announcement also noted that Astellas will not be exercising its option to obtain an exclusive license to the therapy. In October 2022, Astellas bought 15% of Taysha’s outstanding common stock for $50 million with the exclusive option to license TSHA-120 and TSHA-102.

“While Astellas has declined to exercise its option for the GAN program, we remain focused on the needs of patients impacted by devastating diseases and look forward to continuing our relationship with Taysha,” Richard Wilson, Astellas’ senior vice president and primary focus lead of genetic regulation, said in a statement.

Check out our AAV CDMO service to expedite your gene therapy research
About PackGene

PackGene is a CRO & CDMO technology company that specializes in packaging recombinant adeno-associated virus (rAAV) vectors. Since its establishment in 2014, PackGene has been a leader in the AAV vector CRO service field, providing tens of thousands of custom batches of AAV samples to customers in over 20 countries. PackGene offers a one-stop CMC solution for the early development, pre-clinical development, clinical trials, and drug approval of rAAV vector drugs for cell and gene therapy (CGT) companies that is fast, cost-effective, high-quality, and scalable. Additionally, the company provides compliant services for the GMP-scale production of AAVs and plasmids for pharmaceutical companies, utilizing five technology platforms, including the π-Alpha™ 293 cell AAV high-yield platform and the π-Omega™ plasmid high-yield platform. PackGene’s mission is to make gene therapy affordable and accelerate the launch of innovative gene drugs. The company aims to simplify the challenging aspects of gene therapy development and industrialization processes and provide stable, efficient, and economical rAAV Fast Services to accelerate gene and cell therapy development efforts from discovery phase to commercialization.

Related News

Future Of Gamma Delta T Cell Therapies

Gamma delta T cell-based immunotherapies have emerged as a promising frontier in cancer treatment and beyond, building on the success of chimeric antigen receptor T-cell (CAR T cell) therapy and expanding on the potential of the immune system as a therapeutic...

read more

Related Services

Plasmids GMP Services

Multiple scales & grade of solutions of various kind of plasmids suitable for multiple treatments in a fast and cost effective way.


AAV GMP Services

Ranging from small-scale AAV production, to large-scale AAV cGMP manufacturing for animal studies.


aav icon

Technology Platforms

PackGene’s proprietary π-Alpha™ 293 AAV High-yield Platform increases AAV production by 3 to 8 times that of traditional platforms.