First in Human Study to Assess Safety of VIS649 in Healthy Subjects

This is a phase 1, randomized, placebo-controlled, double-blind, single ascending dose study of IV VIS649 in healthy subjects. VIS649 is a monoclonal immunoglobulin G2 (IgG2) antibody targeting the B-cell growth factor APRILL. The study will enroll up to 45 subjects and will be conducted in up to 5 sequential dosing cohorts at four different dose levels, enrolling 9 subjects per cohort. Subjects will be randomized to VIS649 or placebo in a ratio of 7:2 (7 active, 2 placebo). Safety, pharmacokinetic (PK) and pharmacodynamic (PD) data from the initial cohorts will be assessed.

On Day 1, a single dose of VIS649 or placebo will be administered IV. Pharmacokinetics sampling will start with a collection prior to the start of infusion and at multiple timepoints throughout the study. Pharmacodynamics sampling will occur at baseline and multiple timepoints throughout the study. Sentinel subjects will be utilized; the first two subjects in each cohort will be randomized to receive either VIS649 or placebo and will receive study drug at least 24 hours before the remaining subjects in the cohort are dosed. The safety profile of these subjects over the 24 hour post-administration period will be reviewed to determine whether it is appropriate to proceed with enrollment of the remaining subjects in the cohort as planned. This will occur for each dose escalation. The maximum duration of participation (Screening through End-of-study) for individual subjects will be approximately 20 weeks (5 months). The scheduled final visit will occur 16 weeks post-dosing (112 days).