The GDGs discussed future research and highlighted a number of priorities.
1. The effectiveness of fixed-dose combination TB treatment when compared to separate drug formulations in patients with DS-TB disease
- Additional research on the reasons why FDC formulations did not show a clear benefit over separate drug formulations.
- Pharmacokinetic studies of the bioavailability of FDCs versus separate drug formulations and better development of weight band categories for drug dosing.
- The optimal dose of rifampicin, including the use of different drug formulations in all age groups.
- Additional qualitative studies detailing adherence to medication.
- Additional work on FDC formulations to further decrease the pill burden, especially among patients with comorbidities.
2. The use of steroids in the treatment regimen of extrapulmonary TB disease
- The optimal steroid dose for TB meningitis (including different drug formulations).
- The optimal steroid duration for TB meningitis and if this duration differs between different grades of meningitis.
- The different effects of steroids on people who are HIV-positive or HIV-negative, or who are being treated (or not) with ART.
- The relationship between steroid treatment and cancer risk, with reference to the Mayosi et al. study on pericarditis .
3. 4-month regimen of isoniazid, rifapentine, moxifloxacin and pyrazinamide for drug-susceptible pulmonary TB
- Acquisition of drug resistance for Mycobacterium tuberculosis and for other bacteria while on treatment with a 4-month regimen.
- The efficacy of the regimen for patients with extra-pulmonary TB.
- Pharmacokinetic, safety and tolerability studies in younger adolescents and children. A pharmacokinetic sub-study in adults was initiated alongside the trial, and the results were expected within months of the GDG meeting.
- The cost-effectiveness of the shorter regimen.
- Considerations regarding the impact of the 4-month regimen on equity.
- The acceptability of the shorter 4-month regimen, particularly for patients.
- The use of this regimen in specific subgroups - including pregnant and lactating women, children aged less than 12 years, HIV-positive individuals with a CD4 count lower than 100 cells/mm³, people with diabetes mellitus and people with a body weight less than 40 kg.
- Dosing considerations for people weighing less than 40 kg.
- The use and acceptability of FDC formulations for the shorter 4-month regimen.
- Operational research on directly observed treatment versus self-administered therapy.
- Treatment adherence and completion in operational settings.