Four weeks vs twelve weeks: can a shorter TB prevention course work?
NCT ID NCT03785106
First seen Sep 16, 2026 · Last updated Sep 17, 2026 · Updated 1 time
Summary
Researchers are testing whether a 4-week daily course of isoniazid and rifapentine can prevent active tuberculosis as well as the standard 12-week weekly course in people with HIV who have latent TB infection. The trial enrolls about 2,500 adults in a high TB burden country. Both groups also receive vitamin B6. The study measures how many participants stay free of active TB, how many have side effects, and how many complete treatment.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- isoniazid plus rifapentine, given with vitamin B6
- What this could lead to
- If the 4-week daily regimen works as well as the 12-week weekly one, TB prevention could become shorter and easier to finish for people with HIV.
- What could go wrong
- The shorter regimen may not prevent TB as well, or it may cause more side effects that stop people from completing it. This trial is still testing those questions.
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Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 3
Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.
- Participants
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2,500 people
The number who actually took part.
- Started
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Aug 2019
- Expected to finish
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Mar 2038
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 years and older
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Documented HIV-1 infection by standard HIV test or plasma HIV-1 RNA viral load and received ART within 12 months. Participants received ART more than 12 months would be allowed if CD4 cell counts is less than 350 cells/mm3 2. 18 years and older 3. Evidence of latent TB infection, either by TST ≥5 mm or positive interferon gamma release assay (IGRA) or history of close contact with active pulmonary TB\* within 3 months prior entry visit or residing in a high TB burden area\*\* NOTE \* close contact is referred to person living/sharing in the same room with active pulmonary TB participants for \> 4 hours/day \*\* high TB burden areas are defined as areas with an estimated or reported TB prevalence of 100 to 300/100,000, according to the WHO. Thailand is included in high TB burden areas. 4. Laboratory values obtained within 30 days prior to entry * Absolute neutrophil count (ANC) \>750 cells/mm3 * Hemoglobin \>7.4 g/dL * Platelet count \>50,000/mm3 * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\]) and alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase \[SGPT\]) \<3x upper limit of normal (ULN) * Total bilirubin \<2.5 X ULN 5. Chest radiograph or chest computed tomography (CT) scan without evidence of active tuberculosis, unless one has been performed within 90 days prior to entry. 6. Female participants who are participating in sexual activity that could lead to pregnancy must agree to use one reliable non-hormonal form of contraceptive (i.e., condoms, IUD, diaphragm) during RPT treatment and contraception should be remain to 6 weeks post RPT NOTE Female participants who are not of reproductive potential or whose male partner(s) have undergone successful vasectomy with documented azoospermia or have documented azoospermia are eligible without requiring the use of contraceptives. Participant-reported history is acceptable documentation of menopause, hysterectomy, or bilateral oophorectomy or bilateral tubal ligation. 7. All participants must agree not to participate in a conception process (e.g., active attempt to become pregnant or to impregnate, donate sperm, in vitro fertilization) while receiving RPT and for 6 weeks after stopping this drug. 8. Body weight \> 40 kg 9. Ability and willingness of participant to provide informed consent Exclusion Criteria: 1. Treatment for active or latent TB (pulmonary or extrapulmonary) within 2 years prior to study entry or presence of any confirmed or probable active TB at screening. 2. History of Isoniazid (INH) or Rifampicin (RIF)/Rifabutin (RFB) resistant TB at any time prior to study entry or known exposure to INH or RIF/RFB resistant TB (e.g., household member of a person with MDR or XDR TB) at any time prior to study entry. 3. Treatment for \>14 consecutive days with a rifamycin or \>30 consecutive days with INH at any time during the 2 years prior to enrollment. 4. Current or planned use of protease inhibitor-based ART. 5. Currently on a salvage ART regimen, defined as a regimen started due to confirmed HIV virologic failure on a prior ART regimen or due to known HIV drug resistance. 6. History of liver cirrhosis at any time prior to study entry. 7. Evidence of acute hepatitis, such as abdominal pain, jaundice, dark urine, and/or light stools within 90 days prior to entry. 8. Diagnosis of porphyria at any time prior to study entry. 9. Peripheral neuropathy ≥Grade 2 according to the Division of AIDS (DAIDS) Toxicity Table, within 90 days prior to study entry. 10. Known allergy/sensitivity or any hypersensitivity to components of study drug(s) or their formulation. 11. Active drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements. 12. Acute or serious illness requiring systemic treatment and/or hospitalization within 30 days prior to entry. 13. Pregnancy or breastfeeding
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Bhumibol Adulyadej Hospital
Bangkok, 10220, Thailand
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Buddhachinnaraj Hospital
Phitsanulok, 65000, Thailand
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Chiangrai Prachanukroh Hospital
Chiang Rai, 57000, Thailand
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HIV-NAT, Thai Red Cross AIDS Research Centre
Bangkok, 10330, Thailand
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Hatyai Hospital
Songkhla, 90110, Thailand
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King Chulalongkorn Memorial Hospital
Bangkok, 10330, Thailand
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Klang Hospital
Bangkok, 10100, Thailand
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Maharat Nakhon Ratchasima Hospital
Nakhon Ratchasima, 30000, Thailand
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Police General Hospital
Bangkok, 10330, Thailand
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Pranangklao Hospital
Nonthaburi, Changwat Nonthaburi, 11000, Thailand
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Queen Savang Vadhana Memorial Hospital
Chon Buri, 20110, Thailand
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Sanpatong Hospital
Chiang Mai, 50120, Thailand
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Sisaket Hospital
Si Sa Ket, 33000, Thailand
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Srinagarind Hospital
Khon Kaen, 40002, Thailand
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Taksin Hospital
Bangkok, 10600, Thailand
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the Public Health Centre 28 Krung thon buri
Bangkok, 10600, Thailand
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Other studies related to the condition(s) this trial covers.
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