Interim results from ALLIANCE, the first direct study comparing two different tenofovir-containing antiretroviral regimens for the treatment of HIV and hepatitis B (HBV) co-infection, demonstrate the superiority of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF ) on dolutegravir plus tenofovir disoproxil fumarate (DTG + F/TDF), researchers reported here at the 24th International AIDS Conference (AIDS 2022).
While both regimens showed similar efficacy for HIV control, the B/F/TAF regimen produced better HBV results, with greater HBV DNA suppression and significantly greater seroconversion, lead researcher Anchalee Avihingsanon, MD, PhD, reported at a news conference at the meeting. Avihingsanon heads the medical division of the HIV Netherlands Australia Thailand Research Collaboration (HIV-NAT) of the Thai Red Cross AIDS Research Center, in Bangkok, Thailand.
The ongoing Phase 3, multi-country study has 48-week results for 243 participants co-infected with HIV/HBV and treatment-naïve. All subjects received three ART pills per day, with blinded randomization to (Active B/F/TAF + Placebo DTG + Placebo TDF/FTC or Placebo B/F/TAF + Active DTG + Active TDF/FTC). The primary endpoints at 48 weeks were the percentage of participants with HIV-1 RNA < 50 copies/ml and plasma HBV DNA < 29 IU/ml.
For the HIV endpoint, the results showed that both the B/F/TAF and DTG + F/TDF arms had a high degree of suppression (91% and 91%, respectively) p = 0.21), but the B/F/TAF group had significantly higher rates of HBV DNA suppression (63% vs. 43.4%, p = 0.0023) and HBeAg seroconversion (23.3% vs 11.3%), with numerically higher but not statistically significant differences in HBsAg loss/seroconversion (12.6% vs 5.8% and 8.4 % vs. 3.3%), HBeAg loss (25.6% vs. 14.4%), and ALT normalization (73.3% vs. 55.3%).
None of the participants developed treatment-emergent resistance to HIV-1 drugs while taking B/F/TAF, and there were few study drug-related side effects or discontinuations, she reported.
“There is hardly a good reason to give the two pill DTG regimen over one tablet BTG/TAF/FTC in HBV co-infected people living with HIV [PLWH]said Babafemi Taiwo, MD, chief of Infectious Diseases and professor of medicine at Northwestern University in Evanston, Illinois, who was not involved in the study. has that it is a one tablet formulation to be prescribed for HBV co-infected PLWH,” he said. Medscape Medical News. However, he added that the results “should be scratching your head, as TAF is not known to be better than TDF for HBV treatment in individuals without HIV.”
“The lower response rate of the TDF group is still poorly understood,” agrees Avihingsanon, emphasizing that “HBV and HIV/HBV are not the same, and TDF and TAF are also different. TAF has slightly more drug-drug interactions than TDF I think the end product in the liver may be higher What is exciting to me is that there was such a high rate of HBsAg loss and HBs seroconversion in HIV/HBV co-infection which is totally different from HBV mono-infection (<1% at 48 weeks). For me as a researcher, this important finding has an additional benefit to further investigate the immunological outcome for a potential HBV cure strategy." She said the study will remain blinded until week 96, after which further data may shed light on this question.
“Perhaps a larger study would help clarify the impact of TAF versus TDF on measures that failed to achieve statistical significance in this study. Long-term follow-up to better understand the clinical implications of these results may also be helpful, Taiwo added.
The study was funded by Gilead. Avihingsanon reported no relevant disclosures. Taiwo has disclosed that he has served as an advisor to ViiV/GSK, Johnson & Johnson and Merck, and has consulted for Gilead regarding COVID.
24th International AIDS Conference (AIDS 2022). Summary 12565, presented on July 27, 2022 (to the press).
Kate Johnson is a Montreal-based freelance medical journalist who has written about all areas of medicine for over 30 years.
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