Study of Daily Rifapentine for Pulmonary Tuberculosis

The goal of this Phase 2 study is to determine the microbiological activity and safety of rifapentine when given as a component of multidrug intensive phase treatment of smear-positive pulmonary tuberculosis (TB).

Funding Source- FDA Office of Orphan Products Development (OOPD)

Prospective phase II, open-label, single center study in which each experimental rifapentine regimen is evaluated using a two-stage design. Adults (HIV-negative, or HIV-positive with CD4 \> 200 cells/cu mm) suspected to have pulmonary tuberculosis who meet eligibility criteria will be randomized to receive one of three intensive phase regimens. Intensive phase regimens will consist of once daily isoniazid, pyrazinamide, and ethambutol, plus one of the following: rifampin 600 mg once daily OR rifapentine 450 mg once daily OR rifapentine 600 mg once daily. Randomization will be stratified by presence/absence of cavitation on baseline chest radiograph. In Stage 1, 15 subjects will be randomized to each arm, following which there will be an enrollment pause for efficacy and safety assessment. Any rifapentine regimen for which fewer than 6 of 11 evaluable participants have week 8 culture conversion will be discarded.

Stage 2 will randomize subjects into the remaining "accepted arms" with a maximum of 36 additional subjects per arm.

All subjects will continue TB treatment with a conventional continuation phase treatment.

Study Site

Study subjects will be recruited from the University of Cape Town inpatient wards and outpatient clinics.

Estimated Study Duration

It is estimated that 18 months will be required for recruitment and enrollment of study subjects. The estimated duration of participation for each study subject is 18 months, including 2 months of experimental intensive phase TB treatment, 4 months of non-experimental conventional continuation phase TB treatment, and an additional 12 months for follow-up for TB relapse.

Study Management

Study subjects will have study visits on days 0, 7, 14, 21, 28, 35, 42, 49, and 56 for sputum collection and adverse event assessment. Safety laboratory monitoring will be performed on days 14, 28, 42, and 56 and will consist of complete blood count, serum alanine aminotransferase, serum total bilirubin, and serum creatinine. Steady state pharmacokinetic analysis will be performed on approximately day 28. Subjects will have additional study visits at week 10 and at months 4, 6, 12, and 18.