C3PO: Predicting tuberculosis recurrence with blood and sputum tests

Candidate Clinical Correlate of Prognostic Outcome for TB Study

Observational University of California, San Francisco · NCT07018076

This project will test whether new blood and sputum-based tests can identify people who are likely to get tuberculosis again after finishing standard treatment.

Quick facts

Study typeObservational
Enrollment750 (estimated)
Ages12 Years and up
SexAll
SponsorUniversity of California, San Francisco Academic / other
Locations3 sites (Kampala and 2 other locations)
Trial IDNCT07018076 on ClinicalTrials.gov

What this trial studies

C3PO is an observational supplement within the R2D2 TB Network that follows people who completed the 6-month HRZE regimen to look for markers that predict TB coming back. The study collects sputum and blood samples to measure non-culture pharmacodynamic markers such as the RS ratio and host immune-response assays and links those measurements to later recurrence under routine programmatic care. By comparing these biomarkers to clinical outcomes, the study aims to find faster, more accurate predictors of relapse than sputum culture. The work is conducted across multiple outpatient sites in Uganda and Vietnam with academic and federal collaborators.

Who should consider this trial

Good fit: People aged 12 years or older who have just completed the standard 6-month HRZE treatment for drug-susceptible pulmonary tuberculosis and can return for follow-up visits are ideal candidates.

Not a fit: People with drug-resistant TB, those still taking anti-mycobacterial drugs for other reasons, those who finished treatment more than 14 days before screening, or those unwilling to return for follow-up are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the biomarkers could allow shorter, more informative TB drug trials and help target follow-up care to people at higher risk of recurrence.

How similar studies have performed: Preliminary research on markers like the RS ratio and host immune assays has shown promise, but these approaches are not yet validated in large prospective cohorts for predicting TB recurrence.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. . individuals age ≥ 12 years;
2. . have completed treatment for drug-susceptible tuberculosis with the standard 6-month regimen of isoniazid, rifampin, pyrazinamide, and ethambutol (HRZE).

Exclusion Criteria:

1. completed treatment for drug-susceptible tuberculosis \>14 days prior to screening/enrollment;
2. routinely taking any medication with anti-mycobacterial activity (including fluoroquinolones) for any reason not related to tuberculosis treatment within the last 14 days;
3. unwilling to provide informed consent or return for study follow-up visits.

Where this trial is running

Kampala and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions TuberculosisGlobal HealthDiagnostics
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.