Bactericidal Activity and Safety of Nicotinamide in Combination With Bedaquiline, Pretomanid, and Linezolid in Drug-susceptible Pulmonary Tuberculosis

Inclusion Criteria: * Age 18-65 years at consent * Body weight 40-100 kg at screening * Written informed consent obtained * Newly diagnosed pulmonary TB, rifampicin- and isoniazid-sensitive * ≥1+ AFB smear OR positive Xpert semi-quantitative result * Molecular confirmation of M. tuberculosis * Chest X-ray consistent with TB (Investigator assessment) * Able to spontaneously produce sputum * Contraception requirements met * Females Of Child Bearing Potential: 2 approved contraceptive methods or abstinence * Males: contraception or abstinence through 90 days post-dose Exclusion Criteria: * Prior TB within 3 years, \>1 prior episode, or anti-TB treatment within 60 days * Extrapulmonary TB (except non-significant pleural/lymph node disease) * Clinically significant comorbidities or substance abuse impacting safety/compliance * Pregnant or breastfeeding * HIV-positive AND any of the following: * Not on ART or on ART \<3 months * CD4 \<200 cells/µL * Viral load \>200 copies/mL * AIDS-defining illness (other than pulmonary TB) * Screening lab abnormalities (protocol-defined LFTs, hematology, hepatitis B or C, HbA1c) * Clinically significant ECG abnormality * Use of prohibited concomitant medications (e.g., strong CYP3A4 modifiers, certain SSRIs)