From blockbuster drugs to black box warnings, Janus kinase inhibitors (JAKs) have seen dramatic highs and lows in their journey to market access across the last few years. Yet despite the hurdles, JAKs are facing, pharma’s conviction in their potential to generate a paradigm shift in patient care means R&D activity and interest remains undaunted. Will JAK inhibitors triumph over persisting regulatory roadblocks to offer patients a new treatment option? In this white paper, we investigate the current state of JAKs and explore their likelihood of success in the future.