SC1011 (sufenidone) is a novel pyridone derivative with therapeutic potential for idiopathic pulmonary fibrosis (IPF). Two Phase 1 studies evaluated the safety and pharmacokinetics of single (SAD) and multiple ascending doses (MAD) of SC1011 immediate-release (IR) and modified-release (MR) oral formulations in healthy adult subjects. In Phase 1a, subjects were randomized to receive oral SC1011 IR or placebo in SAD (50 mg-300 mg) or MAD (100 mg and 200 mg) twice daily for 7 days. The Phase 1b study consisted of three treatment groups that received 100, 150, or 200 mg SC1011 MR twice daily for 7 days. SC1011 IR was absorbed rapidly (mean time to maximum concentration, T