TSHA-120 is currently being evaluated in an ongoing open-label, nonrandomized, dose-escalation clinical trial conducted by the U.S. National Institute of Neurological Disorders and Stroke (NINDS) division of the National Institutes of Health (NIH). The primary end point is safety, and a primary measure of TSHA-120's clinical efficacy is the Motor Function Measure 32 (MFM32) score. TSHA-120 has demonstrated the potential to improve MFM32 scores in patients. Additional data from the study are expected later this year.

TSHA-120 received rare pediatric disease and orphan drug designations from the U.S. Food and Drug Administration for the treatment of giant axonal neuropathy, a rare inherited genetic disorder that affects the central and peripheral nervous system and is caused by loss-of-function mutations in the gene coding for gigaxonin.

Before the end of 2021, Taysha intends to request an end-of-phase meeting with the FDA and engage with the European Medicines Agency (EMA) and the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan to discuss the regulatory pathway for TSHA-120.

Under the agreement, in exchange for granting Taysha the exclusive worldwide rights to TSHA-120, a leading giant axonal neuropathy patient advocacy group will receive an upfront payment of $5.5 million and will be eligible to receive clinical, regulatory, and commercial milestones totaling up to $19.3 million, as well as a low, single-digit royalty on net sales upon commercialization of the product.