HBV is a common coinfection in HIV patients. We report HBV and HIV outcomes in ART-naïve and experienced HIV/HBV-coinfected subjects enrolled in 4 studies of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF).
HBV serologies were collected at baseline (BL) and week (W) 48 in 4 B/F/TAF studies: Studies 1489 (B/F/TAF vs abacavir/lamivudine/ dolutegravir [DTG, ABC/3TC/DTG] as initial therapy), 1490 (B/F/TAF vs F/TAF+DTG as initial therapy), 1878 (switch from PI + 2 NRTIs to B/F/TAF vs stay on BL regimen [SBR]), and 1844 (maintain ABC/3TC/DTG vs switch to B/F/TAF). Studies 1490 and 1878 permitted HBV-infected patients to enroll; HBV coinfection was excluded from Studies 1489 and 1844 due to ABC/3TC in control arms. HBV seropositive patients had HBV DNA at baseline and W48. Proportion with W48 HBV DNA <29 IU/mL using missing=excluded data imputation was pre-specified for studies 1490 and 1878. HBV serology and DNA results were analyzed to identify incident HBV infections in all 4 studies through W48.
In Study 1490, 14 naïve coinfected subjects (n=12 HBV surface antigen [HBsAg] positive and n=2 HBsAg-/core antibody+ and HBV DNA detectable) were randomized to B/F/TAF (n=8) or DTG+F/TAF (n=6). 1 HBsAg positive subject (DTG+F/TAF group) discontinued study at Day 68. At W48, 11/13 (85%) had HBV DNA <29 IU/mL. 2/11 had HBsAg loss. In Study 1878, 14 treatment experienced coinfected subjects were randomized to stay on BL regimen (SBR, n=6) or switch to B/F/TAF (n=8). 2/14 had HBV DNA >29 IU/mL at BL: 1 (SBR) who discontinued at Day 1 and had no post BL HBV DNA, and 1 (B/F/TAF) who at W48 had HBV DNA ≥29 IU/mL. 12/12 with suppressed HBV DNA at BL maintained HBV DNA <29 IU/mL at W48; none had HBsAg conversion. W48 HIV-1 RNA was <50 copies/mL in 25/28 of those with HIV/HBV coinfection at BL in these two studies (89%). In these two trials plus Studies 1489 and 1844, no patient receiving B/F/TAF, F/TAF or F/TDF acquired HBV. One naïve subject randomized to ABC/3TC/DTG acquired HBV infection by W48.
High rates of HBV suppression were achieved at W48 in naïve HIV/HBV coinfected patients treated with F/TAF regimens. HBV suppression was maintained in experienced patients switching to B/F/TAF. At W48, HIV suppression among HBV coinfected patients was high and comparable to those with HIV mono-infection. Further studies of B/F/TAF and other regimens containing F/TAF for HBV treatment and prevention in HIV-infected patients are warranted.