Early Bactericidal Activity, Safety & Tolerability of Oral GSK3036656 in a Dual Combination With Novel and Established Antitubercular Agents, or Standard of Care in Adults With Rifampicin Susceptible Pulmonary Tuberculosis

A Parallel Group, Phase 2A, Randomised, Open Label Treatment Study to Assess the Early Bactericidal Activity, Safety and Tolerability of GSK3036656 Administered as a Two Drug Combination With Novel and Established Antitubercular Agents, or Standard of Care in Adults With Rifampicin-susceptible Pulmonary Tuberculosis

This study aims to measure the early bactericidal activity (EBA), safety, tolerability and pharmacokinetics with GSK3036656 in combination with either delamanid or bedaquiline or BTZ-043, delamanid in combination with bedaquiline or standard of care for 14 days in participants with newly diagnosed sputum smear positive drug-sensitive pulmonary tuberculosis. Participants will revert to the standard treatment (RIFAFOUR® e-275) once the study treatment (Day 1 to Day 14) has been completed.

Study Overview

• Status: Completed
• Conditions: Tuberculosis
• Intervention / Treatment: Drug: GSK3036656; Drug: Bedaquiline; Drug: Delamanid; Drug: RIFAFOUR e-275; Drug: BTZ-043

• Study Type: Interventional
• Enrollment (Actual): 127
• Phase: Phase 2

Contacts and Locations

Study Locations

• South Africa
  • Bellville, South Africa, 7530
    • GSK Investigational Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants must be 18 to 65 years of age inclusive, at the time of signing the informed consent.

• Participants who have:

  1. New episode of untreated, rifampicin-susceptible pulmonary tuberculosis (TB)
  2. A chest X-ray picture consistent with pulmonary TB
  3. At least one sputum sample positive on direct microscopy for acid-fast bacilli (at least 1+ on the International Union Against Tuberculosis and Lung Disease [IUATLD]/World Health Organization [WHO] scale) or positive on a molecular test (at least medium positive for MTB on Xpert MTB/Rif)
  4. Normal echocardiogram or echocardiogram with normal left ventricular function with at most trace to mild valvular regurgitation is allowed and no valvular stenosis.
  5. A creatinine clearance greater than or equal to (>=)90 mL/minute (Cockroft-Gault formula).
• Male participants are eligible to participate if they agree to barrier precautions until 90 days after last dose.
• A female participant is eligible to participate if she is not pregnant or breast feeding and is a woman of non-childbearing potential (WONCBP) or a woman of childbearing potential (WOCBP) using a contraceptive method that is highly effective. A WOCBP must have a negative pregnancy test urine or serum as required by local regulations before the first dose of study intervention. Only participants who are at least 25 years of age (and females of non-childbearing potential) will be eligible for the positron emission tomography-computed tomography (PET-CT) assessments.
• Capable of giving signed informed consent.

Exclusion Criteria:

• Evidence of a clinically significant (as judged by the Investigator) condition or abnormality (other than the indication being studied) that might compromise safety or the interpretation of trial efficacy or safety endpoints.
• Clinically significant evidence of extrathoracic TB as judged by the Investigator.
• QTc interval corrected for heart rate by Fridericia's formula (QTcF) greater than (>)450 milliseconds (msec).
• Arterial hypertension with Systolic BP >=160 mm Hg or diastolic BP >=100 nm Hg. Participants with well-controlled hypertension may be included if they are using amlodipine for the duration of the study.
• Participants with vitiligo.
• Participants receiving any QT prolonging drugs, including but not limited to fluoroquinolones, macrolides and clofazimine.

• HIV infected participants:

  1. having a cluster of differentiation (CD)4+ count <350 cells/microliters;
  2. having received any antiretroviral therapy medication within the last 30 days;
  3. or having received oral or intravenous antifungal medication within the last 30 days;
  4. or with an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection or malignancies in the last 12 months (except pulmonary TB).
• Presence of Hepatitis B surface antigen (HBsAg) or Positive Hepatitis C antibody test result at screening.
• Participants with diabetes (Type 1 or 2), point of care glycated hemoglobin (HbA1c) above 6.5%, or random glucose over 11.1 millimoles (mmol)/L
• Any diseases or conditions in which use of delamanid or bedaquiline is contraindicated.
• Participants with abnormal laboratory values at screening as graded by the enhanced Common Terminology Criteria for Adverse Events (CTCAE version 5 2017).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Participants receiving GSK3036656+bedaquiline	Drug: GSK3036656; GSK3036656 will be administered.; Drug: Bedaquiline; Bedaquiline will be administered.
Experimental: Participants receiving GSK3036656+delamanid	Drug: GSK3036656; GSK3036656 will be administered.; Drug: Delamanid; Delamanid will be administered.
Experimental: Participants receiving bedaquiline+delamanid	Drug: Bedaquiline; Bedaquiline will be administered.; Drug: Delamanid; Delamanid will be administered.
Experimental: Participants receiving RIFAFOUR e-275	Drug: RIFAFOUR e-275; RIFAFOUR e-275 will be administered.
Experimental: Participants receiving GSK3036656+BTZ-043	Drug: GSK3036656; GSK3036656 will be administered.; Drug: BTZ-043; BTZ-043 will be administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in log10 CFU of Mycobacterium tuberculosis (MTB) (per milliliters of respiratory sputum samples)	The extended early bactericidal activity of each treatment group will be determined by the change from Baseline to Day 14 in log10CFU.	Baseline and up to Day 14

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in time to sputum culture positivity	Time to sputum-culture positivity is the time between sample inoculation and detection of mycobacterial growth in the mycobacterium growth indicator tube.	Baseline and up to Day 14
Number of participants with serious adverse events		Up to Day 28
Number of participants with adverse events of Grade 3 severity or higher		Up to Day 28
Number of participants with adverse events related to study drug		Up to Day 28
Number of participants withdrawn from the treatment due to adverse events		Up to Day 28
Number of participants withdrawn from the study due to adverse events		Up to Day 28
Number of participants with electrocardiogram (ECG) values of potential clinical importance (PCI)		Up to Day 28
Number of participants with hematology laboratory values of PCI		Up to Day 28
Number of participants with clinical chemistry laboratory values of PCI		Up to Day 28
Number of participants with vital signs of PCI		Up to Day 28

Collaborators and Investigators

• Sponsor: GlaxoSmithKline
• Collaborators: Click-TB Consortium
• Investigators: Study Director: GSK Clinical Trials, GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Actual): July 26, 2022
• Primary Completion (Actual): May 27, 2025
• Study Completion (Actual): May 27, 2025

Study Registration Dates

• First Submitted: May 16, 2022
• First Submitted That Met QC Criteria: May 16, 2022
• First Posted (Actual): May 19, 2022

Study Record Updates

• Last Update Posted (Estimated): October 7, 2025
• Last Update Submitted That Met QC Criteria: October 2, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Pulmonary tuberculosis; Bedaquiline; Early bactericidal activity; GSK3036656; Delamanid; BTZ-043; RIFAFOUR
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Actinomycetales Infections; Mycobacterium Infections; Tuberculosis; Tuberculosis, Pulmonary; Anti-Infective Agents; Anti-Bacterial Agents; Antitubercular Agents; GSK656; bedaquiline; OPC-67683; 2-(2-methyl-1,4-dioxa-8-azaspiro(4.5)dec-8-yl)-8-nitro-6-(trifluoromethyl)-4H-1,3-benzothiazin-4-one
• Other Study ID Numbers: 214912

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD for this study will be made available via the Clinical Study Data Request site.
• IPD Sharing Time Frame: IPD will be made available within 6 months of publishing the results of the primary endpoints, key secondary endpoints and safety data of the study.
• IPD Sharing Access Criteria: Access is provided after a research proposal is submitted and has received approval from the Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension can be granted, when justified, for up to another 12 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No