To characterise viral suppression rates (proportion of patients with HIV-1 RNA <50 copies/mL) at week 24 in the BIC/FTC/TAF arm

Proportion of patients with suppressed viral load (HIV-1 RNA<50 copies/mL) at week 24 in the BIC arm (as per FDA snapshot algorithm)

To characterise viral suppression rates (proportion of patients with HIV-1 RNA <50 copies/mL) at weeks 12, 24 and 48 in the standard of care treatment (SOC) arm (currently, TDF 300 mg/3TC 300 mg/DTG 50 mg) and at weeks 12 and 48 in the BIC/FTC/TAF arm

To compare the pharmacokinetics (PK) of BIC when given twice daily and co-administered with Rifampicin during tuberculosis treatment vs when given alone after discontinuation of Rifampicin

To assess the incidence of TB associated IRIS in each arm, through week 24

To characterise the tolerability of treatment in each arm by assessing frequency of clinician- initiated treatment interruptions or switches through week 48

To assess frequency of ART drug resistance mutations in participants with detectable viral load at study visit weeks 24 and 48

Viral suppression rates (HIV-1 RNA<50 copies/mL) at weeks 12, 24 and 48 in the DTG arm and at 12 and 48 weeks in the BIC arm

PK of BIC when given two times per day and co-administered with Rifampicin vs during TB treatment vs when given alone after TB treatment completion

Incidence of TB associated IRIS through week 24, by arm

Grade 3 or higher AEs, SAEs; clinician-initiated treatment interruptions or switches through week 48

Frequency of ART drug resistance mutations in participants with detectable viral load at weeks 24 and 48

To determine the effects of pharmacogenetics (genetic variability in drug metabolising enzymes or drug transporters including but not limited to UGT1A, p-glycoprotein) on BIC/FTC/TAF PK

To compare the pharmacokinetics (PK) of TAF, intracellular TFV-DP, FTC and DTG when given twice daily and co-administered with Rifampicin during tuberculosis treatment vs when given alone after discontinuation of Rifampicin

To determine the PK of TB drugs

To describe the PK in hair of BIC, FTC, TAF during and after co-treatment with Rifampicin. To describe maternal and fetal outcomes among women who become pregnant on-study

PK of FTC, TAF and intracellular TFV-DP when given two times per day and co-administered with Rifampicin vs during TB treatment vs when given alone after TB treatment completion

PK of TB drugs

Effects of pharmacogenetics of drug metabolising enzymes or drug transporters (eg, UGT1A1, CYP3A, p-gp) on BIC/FTC/TAF/DTG PK

Association between hair PK and virologic suppression