Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a progressive, multisystem disorder that typically begins in childhood or adolescence. Caused by mutations in mitochondrial DNA—most often m.3243A>G in the MT-TL1 gene—it leads to seizures, muscle weakness, hearing loss, fatigue, and stroke-like episodes.

Despite its severity and an estimated prevalence of 4.1 per 100,000 people, there are currently no approved treatments for MELAS. A Phase 2 clinical trial in the EU was initiated on May 14, 2025.

Leigh syndrome spectrum (“LSS”) is a rare, inherited mitochondrial disorder that typically begins in infancy or early childhood. It is caused by mutations in either mitochondrial DNA or nuclear genes that impair energy production in cells. Symptoms often include developmental delay, loss of motor skills, muscle weakness, breathing difficulties, and lesions in the brainstem and basal ganglia visible on MRI. The condition is progressive and often life-threatening.

The estimated prevalence of LSS is approximately 1 in 40,000 newborns. There are currently no approved therapies for LSS.  The Company has received FDA clearance to initiate a Phase 2a clinical trial in the U.S. for the treatment of LSS with TTI-0102.

Pediatric MASH (Metabolic dysfunction-associated steatohepatitis) is a serious liver disease in children that is rapidly escalating; marked by fat accumulation, inflammation, and fibrosis. It is the advanced stage of MASLD (Metabolic dysfunction-associated liver disease) and is closely linked to metabolic syndrome. Oxidative stress plays a central role in its progression by disrupting the balance between reactive oxygen species (ROS) and the liver’s antioxidant defenses.

TTI‑0102 has the potential to restore redox balance by boosting intracellular cysteine and glutathione. It may also reduce liver scarring by inhibiting hepatic stellate cell (“HSC”) activation, which drives fibrosis. There are currently no approved treatments for pediatric MASH. Thiogenesis plans to submit an Investigational Medicinal Product Dossier (IMPD) in 2025 to initiate a Phase 2 clinical trial in Europe.

Rett syndrome (RS) is a rare neurodevelopmental disorder that primarily affects young girls and is caused by mutations in the MECP2 gene, which plays a critical role in brain development. RS is characterized by slowed growth, loss of motor and communication skills, seizures, and distinct repetitive hand movements.

In addition to mitochondrial oxidative stress, a hallmark of the disease is the reduced expression of brain-derived neurotrophic factor (BDNF)—a protein essential for neuron development, synaptic connectivity, and cell survival. Thiogenesis has received Orphan Drug Designation for TTI-0102 in Rett syndrome in the European Union.