Trial of a Six-Month Regimen of High-Dose Rifampicin, High-Dose Isoniazid, Linezolid, and Pyrazinamide Versus a Standard Nine-Month Regimen for the Treatment of Adults and Adolescents With Tuberculous Meningitis

The purpose of this study is to compare a 6-month regimen of high-dose rifampicin (RIF), high-dose isoniazid (INH), linezolid (LZD), and pyrazinamide (PZA) versus the World Health Organization (WHO) standard of care (SOC) treatment for tuberculosis meningitis (TBM).

Rationale: TBM is a devastating illness with high risk of mortality and severe neurologic morbidity. Although recent data suggest that significant dose increases in RIF may improve outcomes in TBM, mortality remains high, and enhanced treatment strategies are needed. In addition, limited data are available to guide treatment duration in adults with TBM. The overall goal of this Phase II, randomized, open-label trial is to assess the PK, safety, and longitudinal treatment outcomes of an optimized 6-month regimen of high-dose RIF, high-dose INH, LZD, and PZA to the WHO 9-month SOC regimen for the treatment of TBM. Primary objective: To determine if a regimen of high-dose RIF, high-dose INH, LZD, and PZA improves functional outcomes measured by the modified Rankin Scale (mRS) at 48 weeks compared with WHO SOC for the treatment of TBM. Design: Participants with definite, probable, or possible TBM will be randomized to one of the two study arms below and randomization will be stratified by HIV status and stage of disease as defined by the modified British Medical Research Council (BMRC) Classification TBM Grade. Arm A: RIF 35 mg/kg + INH 15 mg/kg + LZD 1200 mg + PZA 25 mg/kg for 2 weeks, followed by RIF 35 mg/kg + INH 10 mg/kg + LZD 1200 mg + PZA 25 mg/kg for 6 weeks, and then RIF 35 mg/kg and INH 10 mg/kg for 16 weeks, for a total of 24 weeks of study treatment. Arm B: WHO SOC: RIF 10 mg/kg + INH 5 mg/kg + EMB 20 mg/kg + PZA 25 mg/kg for 8 weeks, followed by RIF 10 mg/kg and INH 5 mg/kg for 28 weeks, for a total of 36 weeks of study treatment. Up to 15 mg/kg or a maximum of 900 mg daily of oral RIF will be permitted in this arm at clinician's discretion. All participants in Arms A and B will receive pyridoxine, while receiving INH, and adjunctive corticosteroids according to BMRC TBM grade for at least 6 weeks. All participants in Arms A and B will be followed from randomization to week 72. Procedures: Study visits will include interval history, blood collection for laboratory testing, peripheral neuropathy screening, visual acuity, color vision, and contrast sensitivity visual testing to monitor for AEs. Lumbar puncture will be performed for assessments of CSF microbiology, LAM and other biomarkers. Optional collection and storage of blood and storage of remaining CSF for future testing will occur. Urine will be obtained for LAM assessment. Plasma and CSF PK assessments will be performed. Participants will undergo assessment of functional status with the mRS and WHO DAS 2.0. Participants will also be assessed with a neurocognitive battery and depression questionnaire (PHQ-9).