Rationale: New regimens to shorten tuberculosis treatment and manage patientswith drug-resistant tuberculosiswho are infectedwith HIV are urgently needed. Experimental and clinical evidence suggests that the new drugs bedaquiline (B) and pretomanid (Pa), combined with an existing drug, pyrazinamide (Z), and a repurposed drug, clofazimine (C), may assist treatment shortening of drug-susceptible and drug-resistant tuberculosis. Objectives: To evaluate the 14-day bactericidal activity of C and Z in monotherapy and in combinations with Pa and B. Methods: Groups of 15 treatment-naive, sputum smear-positive patients with pulmonary tuberculosis were randomized to receive combinations of B with Z-C, Pa-Z, Pa-Z-C, and Pa-C, orCor Z alone, or standard combination treatment for 14 days. The primary endpoint was the mean daily fall in log10 Mycobacterium tuberculosis CFU per milliliter sputum estimated by joint nonlinear mixed-effects Bayesian regression modeling. Measurements and Main Results: Estimated activities were 0.167 (95% confidence interval [CI], 0.075-0.257) for B-Pa-Z, 0.151 (95% CI, 0.071-0.232) for standard treatment, 0.124 (95% CI, 0.035-0.214) for B-Z-C, 0.115 (95% CI, 0.039-0.189) for B-Pa-Z-C, and 0.076 (95% CI, 0.005-0.145) for B-Pa-C. Z alone had modest activity (0.036; 95% CI, -0.026 to 0.099). C had no activity alone (-0.017; 95% CI, -0.085 to 0.053) or in combinations. Treatments were well tolerated and safe. Conclusions: B-Pa-Z, including two novel agents without resistance in prevalent M. tuberculosis strains, is a potential new tuberculosis treatment regimen. C had no measurable activity in the first 14 days of treatment.
