SPR301

SPR301 is an investigational AAV9 gene therapy being developed by Spur Therapeutics for the treatment of Parkinson's disease in patients with GBA1 gene mutations. The therapy uses an adeno-associated virus serotype 9 (AAV9) capsid as a delivery vehicle to deliver GCase85, a rationally engineered and more stable version of the human glucocerebrosidase (GCase) enzyme, directly to the brain. The biological target is the GCase enzyme deficiency caused by GBA1 mutations, which leads to the accumulation of toxic substrates and α-synuclein, resulting in the neuronal cell death that characterizes Parkinson's disease. SPR301 is currently in preclinical development, with IND-enabling studies underway to support advancement into a Phase 1/2 clinical trial planned for 2026. Preclinical studies have demonstrated that SPR301 reaches key brain regions, including the substantia nigra, and shows substantially greater reduction of toxic substrates and α-synuclein compared to wildtype GCase delivery. The GCase85 enzyme was originally developed as part of Spur's work on FLT201, their clinical-stage gene therapy for Gaucher disease.