Switch to B/F/TAF maintains viral suppression in people with HIV-1, HBV

Following the switch from dolutegravir plus emtricitabine/tenofovir disoproxil fumarate (DTG+F/TDF), treatment with bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) has shown efficacy in keeping HIV-1 and hepatitis B virus (HBV) at low levels in the blood through 48 weeks of the open-label extension (OLE) phase of the ALLIANCE study. 

Improvements have also been observed in key clinical outcomes, including alanine aminotransferase (ALT) normalization, hepatitis B e antigen (HBeAg) loss and seroconversion, and hepatitis B surface antigen (HBsAg) loss. 

“Overall, B/F/TAF was well tolerated, with no study drug discontinuations due to treatment-emergent adverse events (TEAEs),” said lead study author Dr Anchalee Avihingsanon, HIV-NAT, Thai Red Cross AIDS and Infectious Disease Research Centre, Bangkok, Thailand.  

“These results demonstrate the efficacy and safety of B/F/TAF in people with both HIV-1 and HBV who switched from DTG+F/TDF,” she added. 

Of the 89 OLE participants (median age 34 years) at baseline, 97.8 percent were male at birth, 94.4 percent were Asian, 30.3 percent had ALT levels above the upper limit of normal (ULN), and 58.4 percent were HBeAg positive. In addition, 96.6 percent had HIV-1 RNA <50 c/mL and 83.1 percent had HBV DNA <29 IU/mL. [CROI 2025, abstract 666] 

Eighty-eight participants (98.9) completed the OLE phase of the study. One patient discontinued due to loss to follow-up. At 48 weeks after switching to B/F/TAF, 95.4 percent had HIV-1 RNA <50 c/mL and 86.6 percent had HBV DNA <29 IU/mL. Notably, 100 percent of the participants had HIV-1 viral suppression at weeks 24 and 36, while that for HBV suppression was 87.6 percent and 87.5 percent, respectively. 

Clinical outcomes 

Other key clinical endpoints also showed improvements following the switch to B/F/TAF. Twenty-seven participants (30.3 percent) had abnormal ALT levels at OLE baseline. Of these, more than half (51.9 percent) achieved ALT normalization after 12 weeks, and this proportion remained consistent through week 48 (52.0 percent). 

"A similar trend was observed for ALT normal, with an increasing proportion of participants achieving normal ALT levels,” Avihingsanon said. 

Furthermore, 52 participants (58.4 percent) were HBeAg positive and 77 (86.5 percent) were HBsAg positive at OLE baseline. At 48 weeks after switching to B/F/TAF, HBeAg loss and seroconversion were 17.0 percent and 12.8 percent, while HBsAg loss and seroconversion were 4.3 percent and 0 percent, respectively. 

In terms of safety, 17 participants (19.1 percent) had a TEAE, of which three (3.4 percent) were grade 3 or 4. The most common TEAEs reported were weight gain (9 percent) and low-density lipoprotein cholesterol increase (3 percent). None of them had a TEAE that led to discontinuation, and no one died. 

“Most TEAEs were mild to moderate severity,” Avihingsanon said. 

ALLIANCE was a randomized, double-blind, phase III study of B/F/TAF in comparison with DTG+F/TDF in adults with both HIV-1 and HBV. The OLE phase analysed data from OLE baseline through week 48 for those who switched to B/F/TAF from DTG+F/TDF after the 96-week randomized phase. 

“In treatment-naïve adults with HIV-1 and HBV coinfection, the ALLIANCE study showed that B/F/TAF was noninferior for HIV-1 RNA suppression and superior for HBV DNA suppression compared to DTG+F/TDF at week 48,” Avhihingsanon said.