Recently developed drugs for the treatment of drug-resistant tuberculosis: a research and development case study.

Two drugs with novel mechanisms of action, the diarylquinoline bedaquiline and the nitroimidazole delamanid-as well as pretomanid from the same class of drugs as delamanid-have recently become available to treat drug-resistant tuberculosis (DR-TB) after many decades of little innovation in the field of DR-TB treatment. Despite evidence of improved efficacy and reduced toxicity of multidrug regimens including the two agents, access to bedaquiline and delamanid has been limited in many settings with a high burden of DR-TB and consistently poor treatment outcomes. Aside from regulatory, logistic and cost barriers at country level, uptake of the novel agents was complicated by gaps in knowledge for optimal use in clinical practice after initial market approval.