The anti-tuberculosis agents under development and the challenges ahead.

Tuberculosis (TB) is a serious health problem causing 1.5 million deaths worldwide. After the discovery of first-line anti-TB drugs, the mortality rate declined sharply, however, the emergence of drug-resistant strains and HIV co-infection have led to increased incidence of this disease. A number of new potential antitubercular drug candidates with novel modes of action have entered clinical trials in recent years. Compounds such as gatifloxacin, moxifloxacin and linezolid, the already known antibiotics are currently being evaluated for their anti-TB activity. OPC-67683 and TMC207 have been approved for the treatment of MDR-TB patients recently, while PA-824, SQ109, PNU-100480, AZD5847, LL3858, SQ609, SQ641, BTZ043, DC-159a, CPZEN-45, Q-203, DNB1, TBA-354 are in various phases of clinical and preclinical developments. This review evaluates the current status of TB drug development and future aspects.