Phase 1 Study on the Safety, Tolerability, and Pharmacokinetics of JST-018 in Healthy Adults

This is a Phase 1, first‐in‐human (FIH), randomized, double‐blind, placebo‐controlled,single ascending dose (SAD) study to assess the safety, tolerability, and PK of a singledose of JST‐018 administered IM to healthy participants.The study will be comprised of a minimum of 3 cohorts (Cohorts A, B, and C, with 12participants per cohort), each evaluating a single dose of JST‐018 administered IM. Ineach cohort, 2 sentinel participants will be randomized 1:1 such that one participantreceives JST‐018 and 1 participant receives placebo. Following a favorable blinded safetyreview committee (SRC) review of sentinel safety data collected through Day 8, theremainder of the cohort (10 non‐sentinel participants) will be randomized 4:1 to JST‐018or placebo, and will be dosed.All safety data for all participants in the current cohort through Day 8 will be reviewedby the SRC in a blinded fashion for each dose cohort before escalating to the next dosecohort (for escalation from Cohort A to Cohort B and escalation from Cohort B to CohortC); A recommendation on whether to implement Cohort D (along with a recommended dose ofJST‐018 to be evaluated in Cohort D) may be provided by the SRC following review ofblinded safety data from Cohorts A, B, and C.