Home›Infectious Disease› Rifapentine 15 mg/kg and 20 mg/kg yield higher culture conversion than standard 6-month regimen
Rifapentine 15 mg/kg and 20 mg/kg yield higher culture conversion than standard 6-month regimenTrial Shows Rifapentine Dosage Impacts Tuberculosis Treatment Outcomes
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious DiseasesPublished August 3, 2026Study authors: Li Yang, Song Lingyun, Feng Zhen, Zhang Xiaoqiang, Miao Yan, Chen Xinchang, Lan Yuanbo, Li Qian, Lin…PubMed ↗NCT05401071 ↗DOI ↗Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease
AI-generated summary of the cited source, checked by automated accuracy review.
How we work
Share
Key Takeaway
Note that higher rifapentine doses improve early culture conversion but increase safety-related discontinuation rates.
This Phase 2/3 Stage 1 randomized controlled trial enrolled 400 adults with pulmonary drug-susceptible tuberculosis across 16 sites in China. The study compared three 4-month regimens containing rifapentine (10 mg/kg, 15 mg/kg, or 20 mg/kg) plus isoniazid, moxifloxacin, and pyrazinamide against a standard 6-month regimen of isoniazid, rifampicin, pyrazinamide, and ethambutol.
Primary results showed that the incidence of permanent regimen discontinuation for safety reasons by week 8 was 9.3% (10 mg/kg), 8.9% (15 mg/kg), and 14.6% (20 mg/kg) compared to 3.0% in the control group. Regarding secondary outcomes, culture conversion before week 8 was higher in the rifapentine groups: 73.8% (10 mg/kg), 84.8% (15 mg/kg), and 87.9% (20 mg/kg) versus 78.0% in the control group. Favourable outcomes at the end of treatment were similar across all groups, with rates of 80.9%, 87.1%, and 82.6% for the rifapentine doses compared to 81.4% for the control.
Safety data indicated that safety-related discontinuations were more frequent in the 20 mg/kg group (14.6%) than the 15 mg/kg group (8.9%). A key limitation is that this study represents only Stage 1 of a seamless phase 2/3 trial. Clinically, while rifapentine at 15 and 20 mg/kg may accelerate culture conversion, the higher dose is associated with increased discontinuation for safety reasons.
How this fits prior evidence
How this fits prior evidence: This study addresses a gap in optimizing treatment duration and dosing for pulmonary drug-susceptible tuberculosis. While previous coverage confirmed that shorter rifamycin-containing regimens show comparable efficacy to longer isoniazid monotherapy for latent tuberculosis infection, this trial specifically evaluates the impact of varying rifapentine doses on culture conversion and safety in active pulmonary cases.
Researchers conducted a Phase 2/3 trial involving 400 adults in China to test three different dosages of rifapentine. These were combined with other standard medications to treat pulmonary drug-susceptible tuberculosis. The study compared these regimens against a standard six-month treatment plan.
The results showed that higher doses of rifapentine (15 mg/kg and 20 mg/kg) led to higher rates of culture conversion before week eight compared to the control group. However, there was a notable difference in safety. Patients receiving the highest dose of 20 mg/kg were more likely to stop their treatment early due to safety concerns than those in other groups.
Because this study is only Stage 1 of a larger trial, the results are not yet definitive for everyday practice. While higher doses showed promise in clearing infections faster, the increased risk of stopping treatment at high doses suggests that finding the right balance is important. Patients should talk to their doctors about these specific findings and how they relate to individual care.
What this means for you:
Higher rifapentine doses may speed up culture conversion but are linked to more frequent safety-related dropouts.
Common questions
Is it safe to take high doses of rifapentine for tuberculosis?
The study found that the 20 mg/kg dose of rifapentine had a higher rate of patients stopping treatment for safety reasons (14.6%) compared to the control group (3.0%). Because this was only Stage 1 of a trial, you should consult your doctor about which dosage is safest for your specific condition.
How does rifapentine compare to standard tuberculosis treatment?
The study compared three rifapentine doses against a standard six-month regimen. While the 15 mg/kg and 20 mg/kg groups showed higher culture conversion rates before week eight, the overall favorable outcomes at the end of treatment were similar across all groups, including the control.
How quickly does rifapentine work to clear the infection?
The study measured culture conversion before week 8. The group receiving 15 mg/kg had a 84.8% conversion rate and the 20 mg/kg group had an 87.9% conversion rate, both of which were higher than the 78.0% seen in the standard treatment group.
OBJECTIVES: To evaluate the safety and efficacy across rifapentine doses ranging from 10 to 20 mg/kg for pulmonary drug-susceptible tuberculosis population.
METHODS: The stage 1 of this seamless phase 2/3 randomized controlled trial recruited enrolled adults with drug-susceptible tuberculosis at 16 sites in China between 1 February 2023 and 29 September 2024 (NCT05401071). Participants were randomly divided (1:1:1:1) to receive one of three 4-month regimens containing rifapentine 10, 15, or 20 mg/kg daily plus isoniazid, moxifloxacin, and pyrazinamide, or a standard 6-month regimen consisting of isoniazid, rifampicin, pyrazinamide, and ethambutol. In the stage 1, the primary endpoint was the incidence of permanent regimen discontinuation for safety reasons by week 8. Key secondary endpoints included culture conversion before week 8, adverse events during treatment, and favourable outcomes at the end of treatment.
RESULTS: A total of 400 participants underwent randomization in stage 1. The incidences of primary endpoint were 9.3% (9/97), 8.9% (9/101), and 14.6% (14/96) in the rifapentine 10, 15, and 20 mg/kg groups, and 3.0% (3/99) in the control group, respectively. Culture conversion before week 8 occurred in 73.8% (45/61), 84.8% (56/66), and 87.9% (51/58) of participants in the rifapentine 10, 15, and 20 mg/kg groups, and 78.0% (46/59) in the control group. Favourable outcomes at the end of treatment were similar across the groups: 81.4% (79/97) in the control group, 80.9% in the rifapentine 10 mg/kg group (relative risk [RR], 0.99; 95% CI, 0.87-1.14), 87.1% in the rifapentine 15 mg/kg group (RR, 1.07; 95% CI, 0.95-1.21), and 82.6% in the rifapentine 20 mg/kg group (RR, 1.01; 95% CI, 0.89-1.16).
CONCLUSIONS: Both rifapentine 15 and 20 mg/kg yielded higher culture conversion rates. However, safety-related discontinuation, particularly in the 20 mg/kg group, was more frequent, highlighting the need for careful benefit-risk assessment and enhanced safety monitoring.
