A Phase 3 Study Assessing Safety and Efficacy of Bedaquiline Plus PA-824 Plus Linezolid in Subjects With Drug Resistant Pulmonary Tuberculosis

Global Alliance for TB Drug Development

Status and phase: Completed; Phase 3

Conditions: Pulmonary Tuberculosis

Treatments: Drug: Linezolid; Drug: PA-824; Drug: Bedaquiline

Study type: Interventional

Funder types: Other

Identifiers

NCT02333799

Nix-TB-(B-L-Pa)

Details and patient eligibility

About

The purpose of this study is to evaluate the efficacy, safety, tolerability and pharmacokinetics of bedaquiline plus PA-824 plus linezolid after 6 months of treatment (option for 9 months for participants who remain culture positive at month 4) in participants with either pulmonary extensively drug resistant tuberculosis (XDR-TB), treatment intolerant or non-responsive multi-drug resistant tuberculosis (MDR-TB).

Full description

Up to 200 male and female participants aged 14 and over with confirmed sputum positive for M.tb. in culture pulmonary XDR-TB, or with pulmonary MDR-TB with a documented intolerability or non-response to the best treatment available for 6 months or more will be enrolled.

All participants will have up to a maximum of 9 days for screening, receive 6 months of treatment, and have followup visits performed 1 and 2 months after treatment completion and every 3 months after study treatment completion for 24 months. If a participant is culture positive or revert to being culture positive between Month 4 and Month 6 visits and their clinical condition suggests they may have ongoing TB infection, they may have treatment extended to 9 months (with 24 months of Follow Up) or be withdrawn from the study.

Participants who withdraw after <14 days of IMP should attend an Early Withdrawal visit. Participants who withdraw after >15 days of IMP should return for an Early Withdrawal visit and follow-up visits at 3, 6 and 24 months after their last dose of IMP to check for survival, SAEs and resolution of TB symptoms.

Enrollment: 109 patients

Sex: All

Ages: 14+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria

1. Provide written, informed consent prior to all trial-related procedures (if under 18, include consent of legal guardian).

2. Body weight of ≥35 kg (in light clothing and no shoes).

3. Male or female, aged 14 years or above.

4. Subjects with one of the following pulmonary TB conditions (WHO definitions prior to 2021):

   a. Extensively Drug Resistant Tuberculosis (XDR-TB) with

   i. documented culture positive (for M.tb.) results within 3 months prior to screening or M.tb. confirmed in sputum based on molecular test within 3 months prior to or at screening;

   ii. documented resistance to isoniazid, rifamycins, a fluoroquinolone and an injectable historically at any time or at screening;

   b. Multi-Drug Resistant Tuberculosis (MDR-TB) documented by culture positive results (for M.tb.) within 3 months prior to or at screening with documented non-response to treatment with the best available regimen for 6 months or more prior to enrolment who in the opinion of the Investigator have been adherent to treatment and will be adherent to study regimen;

   c. MDR-TB documented by culture positive (for M.tb.) results within 3 months prior to or at screening who are unable to continue second line drug regimen due to a documented intolerance to:

   i. PAS, ethionamide, aminoglycosides or fluoroquinolones;

   ii. Current treatment not listed above that renders subject eligible for the study in the Investigator's opinion.

5. Chest X-Ray picture (taken within a year prior to screening) consistent with pulmonary TB in the opinion of the Investigator.

Key Exclusion Criteria

1. Karnofsky score < 50 within 30 days prior to entry.

2. Body Mass index (BMI) < 17 kg/m²

3. History of allergy or known hypersensitivity to any of the trial Investigational Medicinal Products or related substances.

4. HIV infected Subjects having a CD4+ count ≤ 50 cells/μL

5. Having participated in other clinical studies with dosing of investigational agents within 8 weeks prior to trial start or currently enrolled in an investigational study that includes treatment with medicinal agents. Subjects who are participating in observational studies or who are in a follow up period of a trial that included drug therapy may be considered for inclusion.

6. Significant cardiac arrhythmia requiring medication.

7. Subjects with the following at Screening:

   1. QTcF interval on ECG >500 msec.
   2. History of additional risk factors for Torsade de Pointes, (e.g., heart failure, hypokalemia, family history of Long QT Syndrome);
   3. Clinically significant ventricular arrhythmias;
   4. Subjects with other cardiac abnormalities that may place them at risk of arrhythmias must be discussed with the sponsor medical monitor before enrolment. Such abnormalities include: Evidence of ventricular pre-excitation (e.g., Wolff Parkinson White syndrome); Electrocardiographic evidence of complete or clinically significant incomplete left bundle branch block or right bundle branch block; Evidence of second or third degree heart block; Intraventricular conduction delay with QRS duration more than 120 msec.

8. Females who have a positive pregnancy test at Screening or already known to be pregnant, breastfeeding, or planning to conceive a child during the study or within 6 months of cessation of treatment. Males planning to conceive a child during the study or within 6 months of cessation of treatment.

9. A peripheral neuropathy of Grade 3 or 4, according to DMID (Appendix 2). Or, subjects with a Grade 1 or 2 neuropathy which is likely to progress/worsen over the course of the study, in the opinion of the Investigator.

10. Concomitant use of Monoamine Oxidase Inhibitors (MAOIs) or prior use within 2 weeks of treatment assignment.

11. Subjects with the following toxicities at Screening as defined by the enhanced Division of Microbiology and Infectious Disease (DMID) adult toxicity table (November 2007):

    a. serum potassium less than the lower limit of normal for the laboratory; b. Hemoglobin level grade 2 or greater (< 8.0 g/dL); c. Platelets grade 2 or greater(<75,000/mm3); d. Absolute neutrophil count (ANC) < 1000/ mm3; e. Aspartate aminotransferase (AST) > 3 x ULN g. Total bilirubin > or = to 2xULN h. Direct bilirubin > ULN i. Serum creatinine level greater than 2 times upper limit of normal j. Albumin <32 g/L

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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109 participants in 1 patient group

Bedaquiline + PA-824 + Linezolid

Experimental group

Description:

bedaquiline 400 mg once daily for 2 weeks then 200mg 3 times per week plus PA-824 200mg once daily plus linezolid 1200mg once daily. A reduction in the dose of linezolid (to either 600 mg qd or 300 mg qd), or temporary cessation of linezolid (due to a linezolid-specific toxicity), or of the full regimen per Investigator discretion was allowed for suspected drug related toxicity. Re-introduction of the regimen could be considered post a cessation not greater than 35 consecutive days. If participants had toxicity events related to linezolid prohibiting further treatment with that drug, they could remain on the bedaquiline and pretomanid study IMP if they received the initial total of 1200 mg daily dose of linezolid for at least the first 4 consecutive weeks of treatment and they were smear negative, or with trace/scanty results and judged to be clinically improving by the Investigator.

Treatment:

Drug: PA-824

Drug: Bedaquiline

Drug: Linezolid