In July 2024, HOOKIPA Pharma announced that the first person has been dosed in a Phase Ib clinical trial of HB-500, an investigational therapeutic vaccine for the treatment of HIV. The trial is to evaluate the safety and tolerability, reactogenicity, and immunogenicity of repeated doses of HB-500 in participants with HIV on suppressive antiretroviral treatment. The arenaviral vaccine was developed in collaboration with Gilead Sciences, and the beginning of the trial ensures that HOOKIPA achieves a $5 million non-dilutive milestone payment through the collaboration and license agreement.
HB-500
HB-500 comprises two genetically engineered replicating vectors based on the arenaviruses Pichinde virus and lymphocytic choriomeningitis virus. The vectors have been engineered to deliver HIV antigens that have been derived from parts of “key, immunogenic regions” of HIV type 1 (HIV-1) proteins that are highly conserved in HIV-1 clade B variants. The designed immunogens differ by amino acid sequence to allow coverage of >80% of circulating HIV-1 viral variants.
HOOKIPA states that the adenovirus technology has “several key advantages” including:
- The ability to induce a robust CD8+ T cell response by directly targeting and activating dendritic cells
- The ability to induce a robust antibody response to disease-specific target antigens
- The possibility for repeat administration to boost immune response
- No need for an adjuvant to stimulate the immune system
- Demonstrated good tolerability in preclinical studies and clinical trials
The trial began with the first participant on 1st July 2024 and comprises two dose escalation cohorts that will be randomised to receive either HB-500 or placebo. Enrolment is ongoing. HOOKIPA takes responsibility for “advancing the HIV programme” through the completion of the Phase Ib clinical trial. Following this, Gilead has the exclusive right to assume further development of the programme.
Taking an important step
CEO of HOOKIPA, Joern Aldag, commented that HIV “impacts the daily lives of millions globally, with no known curative treatment”.
“While current treatments effectively block viral replication and can prevent progression to AIDS, they have not been shown to clear the virus from people living with HIV, requiring lifelong treatment.”
Aldag states that the team is “happy to have begun the Phase Ib trial” after “impressive findings” at the preclinical stage.
“Our team has worked tirelessly, alongside our great collaboration partners at Gilead, to reach this point, and we are excited to take in important step toward finding a curative treatment for HIV.”
For more updates on therapeutic vaccine efforts, don’t forget to subscribe to our weekly newsletters here.
