This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled clinical study that will randomize participants with Progressive Pulmonary Fibrosis to study drug BMS-986278 60mg, 120mg, or Placebo, administered orally, twice a day. Participants are allowed to continue background therapy, such as antifibrotic and immunosuppressant therapies. This study will consist of two parts (Cohort 1 and 2). Cohort 1 will enroll approximately 60 participants with Progressive Pulmonary Fibrosis to evaluate the safety and tolerability of BMS-986278 in which participants will be randomized to receive 60 mg, 120mg, or placebo and this will last approximately 52 weeks. Cohort 2 is a registrational, double-blinded study which will investigate the efficacy, safety, and tolerability of BMS-986278 compared with placebo. Based on data from Cohort 1, the study will design 2 or 3 treatment arms for Cohort 2.