BTZ-043 Dose Evaluation in Combination and Selection

BTZ-043 belongs to the chemical class of benzothiazinones, and is a promising antibiotic for the treatment of Tuberculosis. Its mechanism of action is based on the covalent inhibition of the enzyme decaprenylphosphoryl-ß-D-ribose-2'-epimerase (DprE1), which is essential for the cell wall assembly of mycobacteria. . Formation of the covalent adduct between BTZ-043 and DprE1 results in inhibition of cell wall biosynthesis and loss of viability of Mycobacteria Tuberculosis. BTZ-043 has been evaluated in three clinical studies: a phase Ia, First Time in Human study (FTIH), a two-stage phase Ib multiple ascending dose (MAD) and phase IIa monotherapy early bactericidal activity (EBA) study, and a human ADME (Absorption/Distribution/Metabolism/Excretion) study.

Bedaquiline, is a diarylquinoline compound with a novel mechanism of action against MTB, the inhibition of mycobacterial adenosine triphosphate (ATP) synthase. On the 28th of December 2012, the Food and Drug Administration (FDA) granted accelerated approval to SIRTURO® (bedaquiline) tablets as a part of combination therapy in adults with MDR-TB. It is the first to be introduced specifically for the treatment of MDR-TB in combination with other drugs.

Delamanid is a nitro-dihydro-imidazooxazole derivative that inhibits the synthesis of mycolic acids, a crucial component of the cell wall of MTB. Delamanid has received regulatory approvals in several countries and is currently recommended by WHO for for use in longer MDR- or RR-TB regimens in line with WHO recommendations.

Moxifloxacin belongs to the group of fluoroquinolones (FQ). FQs are a mainstay of MDR-TB treatment, and Moxifloxacin is considered the most potent drug in second line MDR-TB therapy, recently reviewed by WHO, with only moderate pre-existing resistance in the community.