Safety, Reactogenicity and Immunogenicity of HB-502 and HB-501 Versus Placebo in People With HIV on Suppressive ART

NCT ID: NCT06430905

Last Updated: 2025-11-18

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: PHASE1
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-07-01
• Study Completion Date: 2025-07-18

Brief Summary

This is a study of HB-502 and HB-501 alternating 2-vector therapy in people living with human immunodeficiency virus (HIV) who are taking antiretroviral treatment (ART).

The benefits of available ART are short-lived and eventually there is a return of rapid HIV replication and higher viral copy number after a period of initial improvement of infection. The study treatment made of HB-502 and HB-501 is designed to train the body to recognize and fight parts from substances found in HIV.

This trial studies the safety, tolerability, and ability of HB-502 and HB-501 to stimulate an immune response against HIV in people living with HIV.

Participants will receive the study treatment by injection into the muscle every 8 weeks for a duration of 24 weeks, which is followed by another 24 weeks to continue looking closely at the safety profile and anti-HIV immune reaction after the last dose of study treatment.

Detailed Description

This is a first-in-human Phase 1b, randomized, double-blind, placebo-controlled, multicenter study of HB-502 and HB-501 alternating 2-vector therapy in participants with HIV who are in overall good health and on suppressive ART. The study will evaluate the safety, reactogenicity, and immunogenicity of HB-502 and HB-501 alternating 2-vector therapy.

HB-502 and HB-501 are genetically engineered replicating vectors based on the arenaviruses Pichinde virus and lymphocytic choriomeningitis virus, respectively. The HB-502 and HB-501 vectors have been engineered to deliver HIV antigens derived from parts of key, immunogenic regions of HIV type 1 (HIV-1) proteins that are highly conserved within HIV-1 clade B variants. The designed immunogens differ from each other by their amino acid sequence allowing for coverage of >80% of circulating HIV-1 viral variants.

Two different dose levels (Dose Level 1 and Dose Level 2) of HB-502 and HB-501 alternating 2-vector therapy or placebo will be administered intramuscularly every 8 weeks for 24 weeks (i.e., 4 doses at Weeks 0, 8, 16, and 24), which is followed by a 24-week follow-up period.

In total, approximately 30 participants aged 18 to 65 years will be enrolled in this study to receive HB-502 and HB-501 alternating 2-vector therapy or placebo.

About 5 Investigators and study sites in the United States are expected to participate in this study.

Conditions

Human Immunodeficiency Virus (HIV) Infection

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

HB-502 and HB-501 alternating 2-vector therapy (Dose Level 1) OR placebo

Intramuscular injection of HB-502 and HB-501 alternating 2-vector therapy at Dose Level 1 OR placebo every 8 weeks for 24 weeks (injections at Weeks 0, 8, 16, and 24).

Group Type: EXPERIMENTAL

HB-502 and HB-501 alternating 2-vector therapy Dose Level 1

Intervention Type: BIOLOGICAL

Administration of HB-502 and HB-501 alternating 2-vector therapy to 10 participants.

Placebo

Intervention Type: OTHER

Administration of placebo to 5 participants.

HB-502 and HB-501 alternating 2-vector therapy (Dose Level 2) OR placebo

Intramuscular injection of HB-502 and HB-501 alternating 2-vector therapy at Dose Level 2 OR placebo every 8 weeks for 24 weeks (injections at Weeks 0, 8, 16, and 24).

Group Type: EXPERIMENTAL

HB-502 and HB-501 alternating 2-vector therapy Dose Level 2

Intervention Type: BIOLOGICAL

Administration of HB-502 and HB-501 alternating 2-vector therapy to 10 participants.

Placebo

Intervention Type: OTHER

Administration of placebo to 5 participants.

Interventions

HB-502 and HB-501 alternating 2-vector therapy Dose Level 1

Administration of HB-502 and HB-501 alternating 2-vector therapy to 10 participants.

Intervention Type: BIOLOGICAL

HB-502 and HB-501 alternating 2-vector therapy Dose Level 2

Administration of HB-502 and HB-501 alternating 2-vector therapy to 10 participants.

Intervention Type: BIOLOGICAL

Placebo

Administration of placebo to 5 participants.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Participants 18 to 65 years of age.
• Confirmed HIV infection as documented by medical records or confirmatory HIV testing at screening.
• Must be on stable suppressive antiretroviral treatment (ART) for at least 48 weeks prior to screening.
• Must have plasma HIV RNA levels of <50 copies/mL (or lower limit of quantitation) for at least 48 weeks prior to enrollment.
• Must have a cluster of differentiation (CD)4+ cell count >450 cells/mm3 and CD4+ cell % of ≥15% obtained within 40 days prior to enrollment.
• Is in good general health according to the clinical judgment of the site Investigator.

Exclusion Criteria

• History of hypersensitivity or other contraindication to any of the components of the study interventions as determined by the Investigator.
• HIV-associated malignancy according to the National Cancer Institute (including Kaposi's sarcoma), and any type of lymphoma or virus-associated cancers.
• History of HIV-associated neurocognitive disease or progressive multifocal leukoencephalopathy.
• More than stage 2 HIV-related illness based on the Revised Surveillance Case Definition for HIV Infection (CDC 2014).
• Active or recent non-HIV-associated malignancy requiring systemic chemotherapy or surgery within 156 weeks (i.e., 3 years) prior to enrollment.
• Known history of hepatitis B virus (defined as hepatitis B surface antigen reactive) or known active hepatitis C virus infection (defined as hepatitis C virus RNA is detected [qualitative]).
• Current untreated or incompletely treated active TB disease or untreated latent TB infection.
• Has any serious or uncontrolled medical disorder that, in the opinion of the Investigator, may increase the risk associated with study participation or study treatment administration, impair the ability of the participant to receive study treatment, or interfere with the interpretation of the study results.
• Is a previous or current recipient of an investigational HIV vaccine (previous placebo/control recipients are not excluded).
• Received non-HIV experimental vaccine(s) within the last 1 year.
• Has congenital or acquired immunodeficiency, including systemic medication use likely to impair immune response to vaccine in the opinion of the site Investigator, such as history of systemic corticosteroids (long-term use), immunosuppressive anti-cancer or other immunosuppressive agents, interleukins, systemic interferons, systemic chemotherapy, or other medications considered significant by the Investigator within 24 weeks prior to the start of study therapy.
• Received blood products or immunoglobulin within 16 weeks prior to enrollment.
• Received systemic steroids at a dose of ≥10 mg/day (prednisone equivalent) for <30 within 14 days or for ≥30 days within 28 days of first dose of study treatment.
• Received any vaccine within 4 weeks prior to enrollment.
• Initiated antigen-based immunotherapy for allergies within the previous year (stable immunotherapy is not exclusionary).
• History or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the participant's participation for the full duration of the trial, or contraindicate participation in this study, or is not in the best interest of the participant to participate, in the opinion of the treating Investigator.
• Is pregnant or breastfeeding or expecting to conceive or father children starting with the screening visit through a minimum of 12 weeks after the last dose of trial treatment.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hookipa Biotech GmbH

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Head of Clinical Development

Role: STUDY_DIRECTOR

Hookipa Biotech GmbH

Locations

Orlando Immunology Center (OIC)

Orlando, Florida, United States

The Hope Clinic at Emory University

Decatur, Georgia, United States

Brigham and Women´s Hospital

Boston, Massachusetts, United States

Beth Israel Deaconness Medical Center (BIDMC)

Boston, Massachusetts, United States

Perelman Center for Advanced Medicine at the Hospital of the University of Pennsylvania

Philadelphia, Pennsylvania, United States

Countries

United States

Other Identifiers

H-500-001

Identifier Type: -

Identifier Source: org_study_id