TBTC Study 29: Rifapentine During Intensive Phase Tuberculosis (TB) Treatment

This Phase 2, prospective, multicenter, open-label clinical trial evaluated the antimicrobial activity and safety of rifapentine-containing regimens during the intensive phase of pulmonary tuberculosis treatment.

In the main study, adult participants with suspected pulmonary tuberculosis were randomized to receive either a standard intensive-phase regimen consisting of rifampin, isoniazid, pyrazinamide, and ethambutol (RHZE), or an experimental regimen in which rifapentine (10 mg/kg) was substituted for rifampin (PHZE). Treatment was administered five days per week under direct observation for 8 weeks.

The study extension evaluated higher daily doses of rifapentine (10 mg/kg, 15 mg/kg, and 20 mg/kg) in combination with isoniazid, pyrazinamide, and ethambutol, compared to the standard rifampin-based regimen. In the extension, treatment was administered seven days per week.

The primary efficacy endpoint was the proportion of participants with negative sputum cultures at completion of the intensive phase. Secondary endpoints included time to culture conversion, safety and tolerability, and rates of treatment discontinuation.

Following completion of the intensive phase, participants received standard continuation-phase tuberculosis treatment per guidelines.