**3.3 Clofazimine and TBI-166**

Clofazimine is an antibiotic belonging to the class of Riminophenazines that is currently approved for the treatment of leprosy [19, 24]. Clofazimine possesses both antimicrobial and anti-inflammatory properties and although its mechanism of action is still unclear, the outer membrane of bacteria appears to be the primary target of this inhibitor [19]. Although Clofazimine has shown good activity against MDR- and XDR-TB, its efficacy in humans is still under investigation specifically concerning long term use and its major adverse effect of causing skin discoloration [25]. Clofazimine is mainly utilised in combination with other drugs in the second-line treatment of drug-resistant TB and has been classified as a Group 5 medicine by the WHO [24]. TBI-166 a new generation analogue of Clofazimine was demonstrated to exhibit superior antimycobacterial activity in comparison to its predecessor as well as reduced skin discoloration and is currently in a Phase 1 clinical trial [25, 26].
