Tuesday, Taysha Gene Therapies Inc ( TSHA ) shared initial clinical data from the first pediatric patient from the REVEAL Phase 1/2 adolescent and adult trial of TSHA-102, an investigational gene therapy, in adult females with Rett syndrome.

Rett syndrome is a rare neurodevelopmental disorder characterized by loss of communication and hand function, slowing and/or regression of development, motor and respiratory impairment, seizures, intellectual disabilities, and shortened life expectancy.

Results from the first patient and second patient with late motor deterioration stage four Rett syndrome dosed with TSHA-102 in the low dose cohort (5.7×1014 total vg) showed:

Generally well-tolerated with no treatment-emergent serious adverse events as of 35-week assessment post-treatment for patient one and 19-week assessment post-treatment for patient two.

 Improved breathing patterns, sleep quality/duration, and circulation (patient one), and improved breathing patterns and circulation (patient two).

 Improved social interest, vocalization, and ability to use an eye-driven communication device (patient one) and improved social interest (patient two).

 Improved hand function and ability to sit unassisted and move legs (patient one), and improved hand stereotypies (patient two).

The seizure Diary showed stable seizure events at lower levels of anti-seizure medication relative to baseline through 35 weeks post-treatment in patient one and significantly reduced seizure events with lower levels of anti-seizure medication relative to baseline through 19 weeks post-treatment in patient two.

The company received Independent Data Monitoring Committee approval to proceed to early advancement to cohort two (high dose, 1×1015 total vg) in REVEAL adolescent and adult trial and approval to dose second pediatric patient in cohort one (low dose, 5.7×1014 total vg) in REVEAL pediatric trial.

Initial safety and efficacy data from cohort one (low dose, 5.7×1014 total vg) from the REVEAL Adolescent and Adult Trial is expected in the second half of 2024.

Initial data from cohort two (high dose, 1×1015 total vg) in both trials (adolescent/adult and pediatric) is expected in 2H 2024.

As of December 31, 2023, Taysha had $143.9 million in cash and cash equivalents, expected to provide a cash runway into 2026.

Price Action: TSHA shares are up 23.1% at $2.77 on the last check Wednesday.