A Phase 1/2a Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Intrathecally Administered ION717 in Patients With Prion Disease

This is a first-in-human, multi-center study in participants with prion disease. The study will consist of a screening period of up to 6 weeks, a 30-week treatment period, a 142-week open-label extension period and a 32-week post-treatment period. Multiple dose levels will be tested. The trial consists of three Regimens. Regimens 1 and 2 are fully enrolled. Participants in Regimens 1 and 2 received multiple doses of study drug (ION717 and placebo) during the 30-week double-blind treatment period; the order of doses (i.e. whether a given dose was ION717 or placebo) was blinded. The trial sites…