This clinical trial is focused on studying a disease called Progressive Supranuclear Palsy (PSP). PSP is a rare brain disorder that affects movement, balance, and eye movements. The study will test a treatment known as AMX0035, which is a combination of two substances: phenylbutyrate and ursodoxicoltaurine. These substances are being investigated to see if they can help slow down the progression of PSP.

The purpose of the study is to assess the impact of AMX0035 compared to a placebo on the rate of disease progression. Participants in the study will receive either AMX0035 or a placebo, which is a substance with no active medication. The study will last for a period of time, during which participants will take the treatment orally in the form of a powder. The study will monitor changes in the participants’ condition using a scale called the Progressive Supranuclear Palsy Rating Scale (PSPRS), which measures the severity of symptoms.

Throughout the study, participants will have regular visits to check their health and monitor any changes in their symptoms. The study will also track any side effects or adverse events that may occur. The goal is to determine if AMX0035 can effectively slow down the progression of PSP and improve the quality of life for those affected by this condition.