Funding: Wellcome Trust Clinical PhD Fellowship awarded to D.S. (086757/Z/08/A). Funding for the minimum inhibitory concentration assays was provided by a grant from the British Society for Antimicrobial Chemotherapy (GA2015_036P). F.K. has conducted the research as part of his Medical Research Council fellowship (MR/P014534/1). Background . This study aims to explore relationships between baseline demographic covariates, plasma antibiotic exposure, sputum bacillary load, and clinical outcome data to help improve future tuberculosis (TB) treatment response predictions. Methods . Data were available from a longitudinal cohort study in Malawian drug-sensitive TB patients on standard therapy, including steady-state plasma antibiotic exposure (154 patients), sputum bacillary load (102 patients), final outcome (95 patients), and clinical details. Population pharmacokinetic and pharmacokinetic-pharmacodynamic models were developed in the software package NONMEM. Outcome data were analyzed using univariate logistic regression and Cox proportional hazard models in R, a free software for statistical computing. Results . Higher isoniazid exposure correlated with increased bacillary killing in sputum (P