Part A: An interventional, double-blind, randomized, placebo-control design will be used to test JBT-101 in about 22 eligible male or female subjects ≥ 18 and ≤ 70 years of age with moderate-to-severe active skin-predominant dermatomyositis.
Part B: A one-year open-label design to test JBT-101 in subjects who completed Part A without permanent discontinuation of study product because of safety or tolerability reasons.