NCT05473520RecruitingPhase 3
Doxycycline Host-directed Therapy to Improve Lung Function and Decrease Tissue Destruction in Pulmonary Tuberculosis
Doxycycline Host-directed Therapy to Improve Lung Function and Decrease Tissue Destruction in Pulmonary Tuberculosis: A Phase III Randomized Control Trial (Doxy-TB)
Source: ClinicalTrials.gov · Last updated 9 Jun 2026
Brief summary (registry, in English)
Tuberculosis (TB) is a global pandemic that despite successful treatment and bacterial eradication can cause chronic ill health, such as pulmonary impairment after tuberculosis (PIAT) and cardiovascular disease (CVD). A recent Phase 2b double-blind randomised-controlled clinical trial shows that adjunctive doxycycline therapy is safe, accelerates resolution of inflammation, suppresses tissue damaging enzyme activity and decreases pulmonary cavity volume (1). We aim to determine if adjunctive doxycycline can reduce PIAT and improve cardiovascular outcomes in a fully powered Phase III trial of 8 weeks of adjunctive doxycycline alongside standard pulmonary TB (PTB) treatment. The investigators hypothesize that doxycycline inhibits tissue destruction in patients with PTB and thereby leads to improved lung function after treatment. Specific aims 1. To assess improvement in lung function as measured by forced expiratory volume (FEV1) predicted in PTB patients given doxycycline versus placebo. 2. To investigate whether doxycycline will hasten the resolution of pulmonary cavities measured by CT thorax 3. To investigate whether doxycycline can suppress inflammatory markers including matrix metalloproteinases 4. To investigate whether doxycycline can accelerate time to sputum conversion 5. To evaluate the effect of doxycycline on cardiovascular outcomes such as the incidence of acute coronary syndrome (ACS) and pulmonary hypertension 6. To investigate whether doxycycline improves TB drug concentrations in sputum and plasma. 7. To assess the safety profile of doxycycline with concurrent standard anti-tuberculous treatment.
- Status (registry)
- Recruiting
- Phase (registry)
- Phase 3
- Study type
- Interventional
- Enrollment
- 150 (estimated)
- First submitted
- 13 Jun 2022
- Start date
- 24 May 2023
- Primary completion date
- 31 Jan 2030
- Lead sponsor
- National University Hospital, Singapore
- NCT number
- NCT05473520
What you commit to
- Study type: Interventional · Phase 3
- Planned participants: 150
- From 24 May 2023 to the primary completion date, 31 Jan 2030
- 6 sites in 2 countries
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Previous pulmonary TB
- Patients on retinoic acid, neuromuscular blocking agents and pimozide which may increase risk of drug toxicity
- Use of any investigational or non-registered drug, vaccine or medical device other than the study drug within 182 days preceding dosing of study drug, or planned use during the study period
- Enrolment in any other clinical trial involving a systemic drug or intervention involving the lung
Other illness
- HIV co-infection
- Severe, pre-existing lung disease such as pulmonary fibrosis, bronchiectasis, COPD and lung cancer
- Allergies to tetracyclines
- Autoimmune disease and/or on systemic immunosuppressants
Lab values
- ALT \> 3 times upper limit of normal
- Creatinine \> 2 times upper limit of normal
Other
- Pregnant or breast feeding
- Evidence of severe depression, schizophrenia or mania
- Principal investigator assessment of lack of willingness to participate and comply with all requirements including follow-up of the protocol, or identification of any factor felt to significantly increase the participant's risk of suffering an adverse outcome
Who the study is looking for
- Aged 21 years and above
- Patients receiving ≤ 14 days of TB treatment or about to start standard combination TB treatment
- Confirmed pulmonary TB with positive acid-fast bacilli smear and/or positive nucleic acid amplification test (NAAT) and/or TB culture results
- CXR demonstrating pulmonary involvement with cavity or cavities
- Able to provide informed consent
Criteria the registry did not label
- The recruitment target would be 150 patients, with 75 in each arm
Age in the registry: 21 years to - · Sex: All · Does not accept healthy volunteers
Sites (6)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Universiti Malaysia Sabah (UMS), Borneo Medical and Health Research Centre Coordinator of this site? Confirm its status | Kota Kinabalu | Malaysia | Active, not recruiting |
| Klinik Kesihatan Menggatal Coordinator of this site? Confirm its status | Kota Kinabalu | Malaysia | Recruiting |
| Klinik Kesihatan Luyang Coordinator of this site? Confirm its status | Kota Kinabalu | Malaysia | Active, not recruiting |
| Hospital Queen Elizabeth I Coordinator of this site? Confirm its status | Kota Kinabalu | Malaysia | Not yet recruiting |
| TB Control Unit Coordinator of this site? Confirm its status | Singapore | Singapore | Recruiting |
| National University Hospital Coordinator of this site? Confirm its status | Singapore | Singapore | Recruiting |
This page is information, not medical advice. Discuss any trial with your doctor.