The goal of this interventional trial is to evaluate the safety and efficacy of the loading dose regimen 200/100SPaL-4/13 weeks, and the 100SPaL -17 weeks regimen in adults with newly diagnosed, drug-sensitive, smear-positive pulmonary tuberculosis.

Participants (18-65 years) will be randomised 1:1, stratified by country and disease severity, to receive either :

1. a sorfequiline loading-dose regimen (200 mg daily for 4 weeks followed by 100 mg daily for 13 weeks) plus pretomanid 200 mg and linezolid 600 mg daily, or
2. sorfequiline 100 mg daily for 17 weeks plus pretomanid 200 mg and linezolid 600 mg daily. Study treatment is administered orally once daily with food.

The primary objective is to assess safety through 17 weeks of treatment, including treatment-emergent adverse events, ECG findings, vital signs, laboratory assessments, visual acuity, and peripheral neuropathy. Secondary objectives include assessments of efficacy (time to stable sputum culture conversion; favorable outcome and treatment failure/relapse at 26 and 52 weeks after end of treatment) and pharmacokinetics of trial drugs, with exploratory analyses including predictors of culture conversion, exposure-response relationships, and quality of life.

This is a phase 2, randomised, multi-center, partially blinded, clinical trial conducted in 2 treatment arms.

The trial will be performed at multiple centers in South Africa and Tanzania in at approximately 100 participants with DS-TB who meet all the inclusion criteria and none of the exclusion criteria, aged 18 to 65, inclusive. Participants will be randomised to one of the 2 sorfequiline, pretomanid and linezolid containing regimens and will be randomised in 1:1 ratio based on country and severity of disease (AFB 3+ and/or bilateral cavitation). T

The trial will consist of the following periods:

1. Screening period: Screening visit, up to 11 days prior to randomisation (Day 1)

2. Treatment Period: approximately 100 participants will be randomised equally to the 2 treatment arms below:

   • Sorfequiline 200 mg + pretomanid 200 mg + linezolid 600 mg for 4 weeks followed by sorfequiline 100 mg for 13 weeks
   • Sorfequiline 100 mg + pretomanid 200 mg + linezolid 600 mg for 17 week

3. Follow-up Period: 52 weeks after end of treatment

Inclusion Criteria:

• 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 k

Exclusion Criteria:

• Karnofsky score < 60 at screening

• Any evidence of extrapulmonary TB

• Cardiovascular or QT prolongation risk factors Pregnant or breast-feeding

• Laboratory abnormalities as defined in the protocol. • 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 study treatment if ARV therapy is indicated
  • If initiation of ARV therapy is indicated, 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 at https://c-path.org/tools-platforms/tb-pacts/

IPD will be available post trial completion

Researchers will be able to access the IPD (datasets) and supporting information through C-path URL.