AELIX Therapeutics has announced positive results from its randomised, placebo-controlled Phase IIa therapeutic HIV vaccine and immune modulator combination clinical trial.
The AELIX-003 trial evaluated the safety, tolerability, immunogenicity and efficacy of AELIX’s HTI T-cell therapeutic HIV vaccine in combination with Gilead’s investigational Toll-Like Receptor 7 (TLR7) agonist, vesatolimod (VES), in people with HIV on antiretroviral therapy.
VES is an immune modulator being evaluated as part of an investigational combination regimen that could potentially lead to viral remission.
The study met its primary and secondary endpoints for safety, tolerability and immunogenicity. The results were presented at the 2023 Conference on Retroviruses and Opportunistic Infections (CROI).
The trial also evaluated the efficacy of HTI vaccines in combination with VES to avoid, delay or contain viral rebound compared to a placebo group. For this evaluation, participants underwent an analytical treatment interruption (ATI) in their antiretroviral therapy (ART) for up to 24 weeks.
The data show that a higher proportion of HTI+VES-treated participants remained off ART for the full 24 weeks. The combination of the HTI vaccine and VES as part of an HIV cure strategy in early treated people with HIV was safe and well tolerated.
Preliminary immune data suggest that HTI vaccines given in combination with VES induce high levels of HTI-specific T-cell responses; VES consistently induced pharmacodynamic response over multiple doses in combination therapy with the HTI vaccine.
Importantly, HTI vaccines were highly immunogenic in a simpler regimen than in the previous AELIX-002 study, and the vaccine-induced responses were associated with higher time off ART, supporting the contribution of the HTI vaccines to better viral control.
Refocusing the immune response
“These encouraging efficacy data demonstrate that the HTI vaccine in combination with VES may be able to modulate an individual’s HIV-specific immune response in a way that can potentially contribute to a better HIV control in the absence of ongoing ART. The AELIX-003 data are exciting, and confirm what we have seen in the AELIX-002 study, where the HTI vaccine alone also extended the time off ART for the vaccinated participants,” said Dr Christian Brander, Chief Scientific Officer of AELIX.
“The HTI vaccine is aimed at refocusing the immune response to especially vulnerable sites in HIV. The vaccine contains antigenic regions of HIV that are more commonly targeted by individuals who naturally control the virus. Maintenance of viral remission without ART represents the next frontier in HIV infection treatment and an important step towards HIV eradication.”