The goal of this clinical trial is to evaluate 3 dose levels of TBAJ876 for 8 weeks in combination with pretomanid and linezolid, compared to 8 weeks of Isoniazid, rifampicin, pyrazinamide and ethambutol (2HRZE), in adult participants with newly diagnosed, smear-positive, pulmonary drug sensitive tuberculosis (DS-TB).

The main questions the trial aims to answer are:

• What is the optimal dose of TBAJ876 to continue further in development.
• What is the bactericidal activity of bedaquiline with pretomanid and linezolid (B-Pa-L) compared to 2HRZE and TBAJ876-Pa-L over 8 weeks
• What is the efficacy and safety of the 26-week B-Pa-L regimen compared with the SOC (2HRZE/4HR) in participants with DS-TB.

Participants will be seen regularly during treatment (up to 26 weeks) and follow-up (52 weeks post treatment) for safety and efficacy assessments, including but not limited to:

• Safety labs, ECGs, vital signs, physical exams, PK sampling, neuropathy assessments and adverse event monitoring
• Sputum collection

Participants will be treated up to 26 weeks with either:

• TBAJ876 25 mg + pretomanid 200 mg + linezolid 600 mg for 8 weeks followed by HR for 7 to 18 weeks
• TBAJ876 50 mg + pretomanid 200 mg + linezolid 600 mg for 8 weeks followed by HR for 7 to 18 weeks
• TBAJ876 100 mg + pretomanid 200 mg + linezolid 600 mg for 8 weeks followed by HR for 7 to 18 weeks
• Bedaquiline 200 mg + pretomanid 200 mg + linezolid 600 mg for 8 weeks followed by bedaquiline 100 mg + pretomanid 200 mg + linezolid 600 mg for 18 weeks
• Isoniazid (H) + rifampicin (R) + pyrazinamide (Z), ethambutol (E) for 8 weeks followed by HR for 18 weeks (dose based on participant's weight).

TBAJ876 and bedaquiline will be blinded during the first 8 weeks of trial treatment; participants randomised to the TBAJ876 or bedaquiline arms will receive open-label pretomanid and linezolid. Participants randomised to the 2HRZE/4HR arm will receive open-label HRZE.

After receiving 8 weeks of treatment, participants randomised to the TBAJ876-Pa-L treatment arms will receive open-label HR for at least 7 weeks. Treatment completion will be allowed at Week 15 in participants randomised to the TBAJ876-Pa-L arms, if the below criteria are met:

• Week 8 or EOT Make-up Period 1 sputum MGIT culture is negative, and
• The participant has no TB-related symptoms by Week 15. Participants with symptoms that have a more likely alternative explanation are eligible to complete treatment at Week 15.

If the MGIT result is MTB positive and/or there are still TB symptom(s), participants will continue to receive HR (in the 3 TBAJ876 arms) and will complete 18 weeks of treatment with HR, for a total of 26 weeks of treatment. After receiving 8 weeks of trial treatment, all participants randomised to the HRZE arm will receive open-label HR for 18 weeks, for a total of 26 weeks of treatment. After receiving 8 weeks of treatment, a participants randomised to the B-Pa-L arm will receive open-label bedaquiline 100 mg (a reduction from the 200 mg daily dose in the first 8 weeks), pretomanid 200 mg, and linezolid 600 mg daily for 18 weeks, for a total of 26 weeks of trial treatment.

Inclusion Criteria:

• Signed informed consent
• DS-TB as defined as sensitive to rifampicin and isoniazid by rapid sputum-based test AND either newly diagnosed for TB or have a history of being untreated for at least 3 years after cure from a previous episode of TB
• Of non-childbearing potential OR using effective birth control methods
• Body weight ≥ 35 kg

Exclusion Criteria:

• Karnofsky score < 60 at screening
• Any evidence of extrapulmonary TB
• Cardiovascular or QT prolongation risk factors
• Pregnant or breast-feeding

Any of the following lab toxicities:

• Platelets <100,000/mm³
• Creatinine >1.3 x ULN
• Haemoglobin <9.5 g/dL or <95 g/L
• Absolute neutrophil count <800/mm³
• Serum potassium less than the lower limit of normal for the laboratory.
• ALT and/or AST ≥2.5 x ULN
• Total bilirubin ≥1.6 x ULN
• Direct bilirubin >1 x ULN
• Haemoglobin A1c ≥8.0%
• Total lipase ≥1.5 x ULN
• Total amylase ≥1.5 x ULN
• CPK >3 x ULN (if >3 x ULN, enquire about the participant's recent strenuous activity and consider repeating the test within the screening window)
• TSH >1 x ULN
• Positive results at screening for HBsAg, HAV IgM, or hepatitis C antibodies

For participants living with HIV only:

• CD4+ count<200 cells/μL.
• WHO Clinical Stage 4 HIV disease
• Participant does not agree to use DTG/TFV/3TC during trial if ARV therapy is indicated, and randomised to the TBAJ876 or the B-Pa-L regimen
• If initiation of ARV therapy is indicate, participants who are known to be intolerant, non-responsive to DTG/TFV/3TC or have DTG/TFV/3TC as a contraindication.

There is an agreement between the Principal Investigator and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

The results of this trial may be published or presented at scientific meetings. If this is foreseen, the investigator agrees to submit all manuscripts or abstracts to TB Alliance before submission. This allows TB Alliance to protect proprietary information and to provide comments; such consent will not be withheld unreasonably

Finalized results are published following completion of the trial. At that time, requests for the IPD can be made to C-Path.

Requests for the IPD can be made to C-Path at https://c-path.org/tools-platforms/tb-pacts/

TBAJ-876 and the first 8 weeks of bedaquiline will be blinded. Participants randomized to TBAJ-876 or bedaquiline arms will received active TBAJ-876 (and placebo TBAJ876 to blind the dose) and placebo bedaquiline or placebo TBAJ-876 and active bedaquiline