 Two phase 2 TB clinical trials that have shown that substitution of moxifloxacin for ethambutol during the intensive phase of pulmonary TB treatment increases the bactericidal activity with multi-drug, intensive-phase regimen, as assessed by sputum culture conversions to negative after 2 month of treatment. In another study, treatment with a weekly regimen of rifapentine and moxifloxacin during the continuation phase of therapy for a total TB treatment for 6 months was not inferior to daily isoniazid plus rifampin; the efficacy of rifapentine plus moxifloxacin in this trial was important because once-weekly rifapentine with isoniazid instead of moxifloxacin was associated with a higher frequency of relapse and treatment failure. In the REMox phase 3 trial, randomized double-blind trial to test non-inferiority of a seventeen weeks of isoniazid, rifampicin and moxifloxacin supplemented by pyrazinamide for the first eight weeks INH-arm compared to standard 6 months of rifampin based regimen for tuberculosis, the number of participants classified as favorable in the control regimen per protocol was 467 92 and in the INH-arm 436 85 a difference of 6.1 97.5 CI 1.7-10.5. In this trial, the moxifloxacin containing regimen was more bactericidal than the control regimen, but there was insufficient activity to permit a rifampin-moxifloxacin regimen to be shortened to 4 months. The relationship between moxifloxacin concentrations and TB treatment outcomes when moxifloxacin is given as part of high-dose rifapentine-based multidrug treatment for drug-sensitive TB is unknown. Further, the target exposure of moxifloxacin for treatment of TB has not been defined. 