Table 1.
Overview of bictegravir/emtricitabine/tenofovir alafenamide switch studies in virologically suppressed people with HIV.
| All studies | Study 4030 | Study 4580 | Study 1844 | Study 1878 | Study 4449 | Study 1474 | |
| Screening resistance criteria: M184V/I | – | Allowed | Allowed | Excluded | Excluded | Excluded | Excluded |
| Screening resistance criteria: bictegravir-associated | – | Excluded | Excluded | Excluded | Excluded | Excluded | Excluded |
| Screening resistance criteria: TAF-associated | – | Allowed | Excluded | Excluded | Excluded | Excluded | Excluded |
| Baseline antiretroviral regimena | – | DTG + either FTC/TDF or FTC/TAF | Any 3rd agent + 2 NRTIs | DTG/ABC/3TC (single or multiple tablets) | Boosted DRV or ATV + either FTC/TDF or ABC/3TC | EVG/COBI/ FTC/TAF or any 3rd agent + FTC/TDF | Any 3rd agent + 2 NRTIs |
| Trial design | – | Double-blind placebo-controlled randomized 1 : 1 switch to B/F/TAF or DTG + FTC/TAF | Open-label randomized 2 : 1 switch to B/F/TAF or stay on baseline regimen | Double-blind placebo-controlled randomized 1 : 1 switch to B/F/TAF or DTG/ABC/3TC | Open-label randomized 1 : 1 switch to B/F/TAF or stay on baseline regimen | Open-label single arm switch to B/F/TAF | Open-label single arm switch to B/F/TAF |
| Participants enrolled (n) | 2386 | 565 | 495 | 563 | 577 | 86 | 100 |
| Median age (criteria for study) (years) | 48 | 51 (≥18) | 49 (≥18) | 46 (≥18) | 48 (≥18) | 69 (≥65) | 12 (6-<18) |
| Median time since ART initiation (IQR) (years) | 8.3 (4.3–15.4) | 10.1 (4.4–18.7) | 10.4 (5.9–17.3) | 5.5 (2.7–10) | 7.7 (4.1–14.0) | 14.9 (6.9–19.3) | 10.1 (7.4–11.4) |
| Participants switched to B/F/TAF (n) | 2044 | 284 | 493b | 547b | 534b | 86 | 100 |
| Median B/F/TAF treatment duration (IQR) (weeks) | 72 (51–102) | 59 (53–63) | 71 (48–72) | 96 (49–119) | 101 (72–120) | 96 (95–96) | 50 (30–52) |
| Participants included in LOCF analysisc (n) | 2034 | 283 | 489 | 545 | 532 | 85 | 100 |
| Timepoint for LOCF analysis | - | Week 48 | Week 72/48d | End of study | End of study | Week 96 | Week 48/24e |
| HIV-1 RNA <50 copies/ml at last visit by LOCF, % (n/N) | 99% (2012/2034) | >99% (282/283) | 99% (486/489) | 98% (535/545) | 99% (525/532) | 100% (85/85) | 99% (99/100) |
| Baseline PR/RT genotype available, % (n/N) | 90% (1825/2034) | 84% (237/283) | 98% (468/489) | 96% (522/545) | 94% (498/532) | 98% (83/85) | 17% (17/100) |
| Baseline M184V/I, % (n/N) | 10% (182/1825) | 20% (47/237) | 11% (50/468) | 3% (17/522) | 12% (62/498) | 4% (3/83) | 18% (3/17) |
| Baseline M184V/I + ≥1 other resistance substitution, % (n/N) | 81% (147/182) | 72% (34/47) | 88% (44/50) | 82% (14/17) | 79% (49/62) | 100% (3/3) | 100% (3/3) |
| M184V/I HIV-1 RNA <50 copies/ml at last visit by LOCF, % (n/N) | 98% (179/182) | 100% (47/47) | 100% (50/50) | 100% (17/17) | 95% (59/62) | 100% (3/3) | 100% (3/3) |
| Treatment emergent resistance to B/F/TAF (n) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
ART, antiretroviral therapy; B/F/TAF, bictegravir/emtricitabine/tenofovir alafenamide; IQR, interquartile range; PR/RT, protease/reverse transcriptase.
Baseline antiretroviral regimens consisted of two nucleoside reverse transcriptase inhibitors (NRTIs), such as abacavir (ABC) and lamivudine (3TC) or emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF), and a third agent, such as dolutegravir (DTG), darunavir (DVR), atazanavir (ATV) or elvitegravir boosted by cobicistat (EVG/COBI).
Participants switched to B/F/TAF at baseline (4580: n = 330, 1844: n = 282, 1878: n = 290) or at weeks 24 (4580: n = 163) or 48 (1844: n = 265, 1878: n = 244).
Virologic outcomes based on last available on-treatment postswitch HIV-1 RNA using last observation carried forward (LOCF) imputation were determined for participants who switched to B/F/TAF and had at least one postswitch on-treatment HIV-1 RNA measurement.
Participants included in the LOCF analysis had outcomes determined at week 72 (n = 327 switched at baseline) or week 48 (n = 162 switched at week 24).
Participants included in the LOCF analysis had outcomes determined at week 48 (n = 75) or week 24 (n = 25) based on duration of B/F/TAF treatment at time of analysis.