Drug development for neglected ultra-rare diseases of no commercial interest: Challenges and opportunities

Ultra-rare diseases, particularly those that affect a few hundred patients worldwide, are of little commercial interest to the pharmaceutical industry. Patient-led organizations have made remarkable progress in funding the early-stage, academic development of therapies for such neglected ultra-rare conditions. But the long and difficult path to translate most academic proof-of-concept studies into approved medicines means that very few therapies ever reach patients. Here, we discuss some of the roadblocks to the development of therapeutics for conditions of limited commercial interest and propose ways to overcome these obstacles.