Voyager Therapeutics (VYGR.O): ARO-MAPT Data Continue to Support the Broader Tau-Silencing Thesis; Positive Readthrough for Voyager's VY1706

Arrowhead (covered by Eric Joseph, see his take here) reported interim Ph1/2a data for ARO-MAPT, an RNAi therapeutic targeting MAPT (tau), demonstrating up to 73% mean CSF tau reduction and 85% maximum individual reduction in healthy volunteers following subcutaneous administration. Beyond validating ARO-MAPT itself, the data represent the first clinical proof-of-concept for systemic siRNA delivery across the blood-brain-barrier and provide additional validation for tau-lowering strategies more broadly. We view the results as a positive readthrough for Voyager's VY1706, a tau-silencing gene therapy that recently entered the clinic (NCT07764146). Importantly, the update further supports the growing body of evidence suggesting that substantial tau reduction may be both achievable and tolerable in humans, while reinforcing MAPT as an attractive therapeutic target across Alzheimer's disease. In the ongoing Ph1/2a study, healthy volunteers receiving doses of 2.1 mg/kg or 6.4 mg/kg on Days 1