Prevail Therapeutics Inc. announced that the first patient has been dosed in the Phase 1/2 PROCLAIM clinical trial evaluating PR006, an investigational AAV9 gene therapy delivering the GRN gene, for the treatment of frontotemporal dementia patients with GRN mutations (FTD-GRN). The PROCLAIM trial is a Phase 1/2 open-label trial investigating the safety and tolerability of PR006 as well as key biomarkers and exploratory efficacy endpoints. The Company expects to enroll up to 15 patients, and it currently anticipates it will provide a biomarker and safety analysis on a subset of patients enrolled in the PROCLAIM trial in 2021. PR006 has been granted Orphan Drug designation for the treatment of FTD and Fast Track designation for the treatment of FTD-GRN by the U.S. Food and Drug Administration, as well as orphan designation for the treatment of FTD by the European Commission. Frontotemporal dementia (FTD) is the second most common cause of dementia in people under the age of 65, after Alzheimer’s disease. FTD affects 50,000 to 60,000 people in the U.S. and 80,000 to 110,000 individuals in the European Union. FTD-GRN represents 5-10% of all patients with FTD. FTD results from the progressive degeneration of the frontal and temporal lobes of the brain, which control decision-making, behavior, emotion and language. In FTD-GRN patients, reduced levels of progranulin lead to age-dependent lysosomal dysfunction, neuroinflammation and neurodegeneration. There are no approved treatments for FTD or FTD-GRN.