Dose, Safety, Tolerability, and Immunogenicity of an HIV-1 Vaccine, VRC-HIVRGP096-00-VP, With Alum in Healthy Adults

Design:

This is a Phase I, open-label, dose escalation study to evaluate the dose, safety, tolerability, and immunogenicity of VRC-HIVRGP096-00-VP (Trimer 4571) with aluminum hydroxide suspension (alum) as adjuvant in a three-injection regimen. The hypotheses were that the vaccine will be safe and tolerable and will induce detectable immune responses. The primary objective was to evaluate the safety and tolerability of the investigational vaccine at three doses administered with alum. Secondary objectives were to evaluate humoral and cellular immunogenicity of the investigational vaccine regimens.

Study Product:

VRC-HIVRGP096-00-VP (Trimer 4571) was developed by the Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases (NIAID). The soluble HIV-1 envelope product consists of an HIV-1 envelope (Env) trimer variant, derived from clade A, strain BG505, with stabilizing mutations and engineered disulfide bonds, specifically recognized by broadly neutralizing antibodies and resists gp120 conformational change caused by CD4 binding. Injections were administered intramuscularly (IM) and subcutaneously (SC) in a 1 mL volume by needle and syringe. The product was provided at a 500 mcg/mL concentration in 3 mL glass vials filled to 1.2 +/- 0.10 mL. Adjuvant is an aluminum hydroxide suspension (alum) provided in a sterile, pyrogen-free suspension at a concentration of 5 mg/mL in 3 mL glass vials filled to 0.7 +/- 0.10 mL.

Participants:

Healthy adults ages 18 to 50.

Study Plan:

Participants received VRC-HIVRGP096-00-VP at doses of 100 mcg or 500 mcg, both with 500 mcg alum field mixed, administered via IM or SC injections. A dose escalation evaluation occurred to ensure the safety data supported proceeding to the higher dose. Participants were evaluated for safety and immune responses through blood collection at specified timepoints throughout the study.

The study schema is below:

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Group 1: Participants = 3; Route = IM; Dose (mcg) = 100; Day** 0, Week** 8, Week** 20

Group 2: Participants = 3; Route = SC; Dose (mcg) = 100; Day** 0, Week** 8, Week** 20

Group 3: Participants = 5; Route = IM; Dose (mcg) = 500; Day** 0, Week** 8, Week** 20

Group 4: Participants = 5; Route = SC; Dose (mcg) = 500; Day** 0, Week** 8, Week** 20

Total = 16 Participants

**500 mcg of alum was mixed with Trimer 4571 for all groups

Duration:

Participants were followed for 40 weeks.

• INCLUSION CRITERIA:

A participant must have met all of the following criteria:

• Able and willing to complete the informed consent process.
• 18-50 years old, inclusive, on day of enrollment.
• Available for clinic follow-up through the last study visit.
• Able to provide proof of identity to the satisfaction of the study clinician completing the enrollment process.
• Willing to donate blood for sample storage to be used for future research.
• In good general health without clinically significant medical history.
• Physical examination and laboratory results without clinically significant findings.
• Body Mass Index (BMI) less than or equal to 40.
• Assessed as low risk for human immunodeficiency virus (HIV) acquisition by agreeing to discuss HIV infection risks, agreeing to risk reduction counseling, and agreeing to avoid behavior associated with high risk of HIV exposure through the end of study.
• Screening laboratory values within 56 days prior to enrollment that met the following criteria:

• Hemoglobin within the institutional normal limits
• White blood cell (WBC) count between 2,500-12,000/mm^3
• WBC differential absolute cell counts either within institutional normal range or accompanied by site Principal Investigator (PI) or Associate Investigator (AI) approval, except neutrophils and lymphocytes must specifically be within the range of greater than or equal to 0.75 x the lower limit of normal (LLN) and lees than or equal to 1.25 x the upper limit of normal (ULN) for neutrophil and lymphocyte absolute counts
• Platelets = 125,000-500,000/m^3
• Alanine aminotransferase (ALT) less than or equal to 1.25 x ULN based on the institutional normal range
• Serum creatinine less than or equal to 1.1 x ULN based on the institutional normal range
• Negative for HIV infection by an FDA approved method of detection

Woman-specific (if presumed to be of childbearing potential):

• Agrees to use effective means of birth control from at least 21 days prior to enrollment through the end of the study.
• Negative beta-HCG (human chorionic gonadotropin) pregnancy test (urine or serum) on day of enrollment.

Exclusion criteria

A participant was excluded if one or more of the following conditions apply:

Woman-specific:

• Breast-feeding or planning to become pregnant through the end of study.

Participant has received any of the following:

• An investigational HIV vaccine.
• Systemic glucocorticoid use equal or greater than prednisone 20mg/day within 4 weeks prior to enrollment, or other medication use likely to impair vaccine response.
• Blood products within 16 weeks prior to enrollment.
• Live attenuated vaccines within 4 weeks prior to enrollment.
• Inactivated vaccines within 2 weeks prior to enrollment.
• Investigational research agents within 4 weeks prior to enrollment.
• Current allergen immunotherapy with antigen injections, unless on maintenance schedule.
• Current anti-tuberculosis (TB) prophylaxis or therapy.

Participant had any of the following:

• Serious reactions to vaccines that preclude receipt of study injections as determined by the principal investigator or designee.
• Hereditary angioedema, acquired angioedema, or idiopathic forms of angioedema.
• Hypertension that is not well controlled.
• Evidence of significant autoimmune disease or immunodeficiency.
• Idiopathic urticaria within the past year.
• Bleeding disorder diagnosed by a doctor (e.g. factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with IM injections or blood draws.
• Seizure disorder other than: 1) febrile seizures, 2) seizures secondary to alcohol withdrawal more than 3 years ago, or 3) seizures that have not required treatment within the last 3 years.
• Asplenia or functional asplenia.
• Any other chronic or clinically significant condition that in the opinion of the investigator would jeopardize the safety or rights of the study subject including but not limited to: diabetes mellitus type I, chronic hepatitis; OR clinically significant forms of: drug or alcohol abuse, asthma, psychiatric disorders, heart disease, or cancer.