Safety and Immunogenicity of the Na-APR-1 Hookworm Vaccine in Healthy Adults

Study Overview
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Brief Summary
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Hookworms digest hemoglobin from erythrocytes for use as an energy source via a proteolytic cascade that begins with the aspartic protease, APR-1. Vaccination with recombinant APR-1 has protected animals from infection in challenge studies. This study will evaluate the safety and immunogenicity of two formulations of Na-APR-1 (M74) in healthy adult volunteers when co-administered with different concentrations of the immunostimulant GLA-AF.

Detailed Description
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Open-label, dose-escalation phase 1 clinical trial in healthy, hookworm-naïve adults: Study site: George Washington Medical Faculty Associates, Washington, DC Number of participants: 40 in 2 cohorts of 20. In Cohort 1 five (5) volunteers will receive 30 µg Na-APR-1 (M74) /Alhydrogel®, five (5) will receive 30 µg Na-APR-1 (M74)/Alhydrogel® plus 2.5 µg GLA-AF, and ten (10) will receive 30 µg Na-APR-1 (M74) /Alhydrogel® plus 5 µg GLA-AF. In Cohort 2 five (5) volunteers will receive 100 µg Na-APR-1 (M74)/Alhydrogel®, five (5) will receive 100 µg Na-APR-1 (M74) /Alhydrogel® plus 2.5 µg GLA-AF, and ten (10) will receive 100 µg Na-APR-1 (M74)/Alhydrogel® plus 5 µg GLA-AF. The cohorts will be enrolled in a staggered fashion with safety data assessed prior to the Na-APR-1 dose escalation from 30 to 100 µg. In addition, within each cohort, vaccinations will be staggered such that formulations containing 0, 2.5, and 5 µg GLA-AF will be tested sequentially: for example, those receiving Na-APR-1 (M74)/Alhydrogel® in combination with 2.5 µg GLA-AF will be vaccinated no sooner than 3 days after the last volunteer is vaccinated with the formulation containing no GLA-AF, whereas those vaccinated with Na-APR-1 (M74)/Alhydrogel® plus 5 µg GLA-AF will be vaccinated no sooner than 7 days after the last one receives the 2.5 µg GLA-AF formulation. Immunization schedule: Study days 0, 56 and 112. Route: IM in the deltoid muscle. Doses of Na-APR-1 (M74) to be tested: 30 and 100 µg. Doses of Alhydrogel®: 240 and 800 µg for the 30 and 100 µg doses of Na-APR-1 (M74), respectively. Doses of GLA-AF to be tested: 2.5 µg and 5 µg. Study duration: 44 weeks (10 months) per study participant; total duration of the study estimated at approximately 13 months.

Official Title
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Phase 1 Study of the Safety and Immunogenicity of Na-APR-1 (M74)/Alhydrogel® in Healthy Adults

Conditions
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Hookworm Infection, Hookworm Disease

Intervention / Treatment
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* Biological: Na-APR-1 (M74)/Alhydrogel®
* Biological: Gluco-Pyranosylphospho-Lipid A Aqueous Formulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males or females between 18 and 50 years, inclusive. Good general health as determined by means of the screening procedure. Available for the duration of the trial (44 weeks). Willingness to participate in the study as evidenced by signing the informed consent document. Exclusion Criteria: Pregnancy as determined by a positive urine human choriogonadotropin (hCG) (if female). Participant unwilling to use reliable contraception methods up until one month following the third immunization (if female and not surgically sterile, abstinent or at least 2 years post-menopausal). Currently lactating and breast-feeding (if female). Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies. Known or suspected immunodeficiency. Laboratory evidence of liver disease (alanine aminotransferase [ALT] greater than 1.25-times the upper reference limit). Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit, or more than trace protein or blood on urine dipstick testing). Laboratory evidence of hematologic disease (hemoglobin <11.5 g/dl [females] or <12.5 g/dl [males]; absolute leukocyte count <3600/mm3 or >10.7 x 103/mm3; absolute neutrophil count [ANC] <1700/ mm3; absolute lymphocyte count <700/mm3; or platelet count <140,000/mm3). Laboratory evidence of a coagulopathy (PTT or PT INR greater than 1.1-times the upper reference limit). Serum glucose (random) greater than 1.2-times the upper reference limit. Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol. Participation in another investigational vaccine or drug trial within 30 days of starting this study. Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months. History of a severe allergic reaction or anaphylaxis. Severe asthma as defined by the need for daily use of inhalers or emergency clinic visit or hospitalization within 6 months of the volunteer's expected first vaccination in the study. Positive ELISA for hepatitis B surface antigen (HBsAg). Positive confirmatory test for HIV infection. Positive confirmatory test for hepatitis C virus (HCV) infection. Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of the volunteer's expected first vaccination in this study. Receipt of a live vaccine within 4 weeks or a killed vaccine within 2 weeks prior to the volunteer's expected first vaccination in the study. History of a surgical splenectomy. Receipt of blood products within the past 6 months. History of previous infection with hookworm or residence for more than 6 months in a hookworm-endemic area.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 30 µg Na-APR-1 (M74)/Alhydrogel®<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;|
| Experimental: 30 µg Na-APR-1 (M74)/Alhydrogel® plus 2.5 µg GLA-AF<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;Biological: Gluco-Pyranosylphospho-Lipid A Aqueous Formulation<br>* GLA-AF contains a synthetic monophosphoryl lipid A (MPL) molecule that has Toll-Like Receptor-4 agonist activity. MPL is itself derived from the lipopolysaccharide (LPS) of Salmonella minnesota, a natural TLR4 agonist that is pyrogenic and can induce toxic shock. LPS, and more specifically, its lipid A component, has long been known for its strong adjuvant effects; however, its high toxicity has precluded its use in a vaccine formulation.<br>* Other names: GLA-AF;|
| Experimental: 30 µg Na-APR-1 (M74)/Alhydrogel® plus 5.0 µg GLA-AF<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;Biological: Gluco-Pyranosylphospho-Lipid A Aqueous Formulation<br>* GLA-AF contains a synthetic monophosphoryl lipid A (MPL) molecule that has Toll-Like Receptor-4 agonist activity. MPL is itself derived from the lipopolysaccharide (LPS) of Salmonella minnesota, a natural TLR4 agonist that is pyrogenic and can induce toxic shock. LPS, and more specifically, its lipid A component, has long been known for its strong adjuvant effects; however, its high toxicity has precluded its use in a vaccine formulation.<br>* Other names: GLA-AF;|
| Experimental: 100 µg Na-APR-1 (M74)/Alhydrogel®<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;|
| Experimental: 100 µg Na-APR-1 (M74)/Alhydrogel® plus 2.5 µg GLA-AF<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;Biological: Gluco-Pyranosylphospho-Lipid A Aqueous Formulation<br>* GLA-AF contains a synthetic monophosphoryl lipid A (MPL) molecule that has Toll-Like Receptor-4 agonist activity. MPL is itself derived from the lipopolysaccharide (LPS) of Salmonella minnesota, a natural TLR4 agonist that is pyrogenic and can induce toxic shock. LPS, and more specifically, its lipid A component, has long been known for its strong adjuvant effects; however, its high toxicity has precluded its use in a vaccine formulation.<br>* Other names: GLA-AF;|
| Experimental: 100 µg Na-APR-1 (M74)/Alhydrogel® plus 5.0 µg GLA-AF<br> | Biological: Na-APR-1 (M74)/Alhydrogel®<br>* The Na-APR-1 (M74) candidate vaccine contains the recombinant Na-APR-1 (M74) protein expressed by Nicotiana plants. Purified Na-APR-1 (M74) was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10 mM imidazole, 150 mM sodium chloride and 0.3% Empigen BB, with pH 7.4 ± 0.1. The final concentration of Na-APR-1 (M74) in the drug product is 0.1 mg/ml, whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-APR-1 (M74) will be delivered by injecting different volumes of the 0.1 mg/ml Na-APR-1 (M74) preparation.<br>* Other names: Necator americanus Aspartic Protease-1;Biological: Gluco-Pyranosylphospho-Lipid A Aqueous Formulation<br>* GLA-AF contains a synthetic monophosphoryl lipid A (MPL) molecule that has Toll-Like Receptor-4 agonist activity. MPL is itself derived from the lipopolysaccharide (LPS) of Salmonella minnesota, a natural TLR4 agonist that is pyrogenic and can induce toxic shock. LPS, and more specifically, its lipid A component, has long been known for its strong adjuvant effects; however, its high toxicity has precluded its use in a vaccine formulation.<br>* Other names: GLA-AF;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vaccine-related Adverse Events | The frequency of immediate, systemic, and local injection site adverse events will be summarized. Adverse events will be assessed by study team members at 1 hour post-vaccination as well as 3, 7, 14, and 28 days following each vaccination. In addition, study participants will be asked to complete symptom diaries for the 7 days after each vaccination. | Day 290 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| IgG antibody response to Na-APR-1 | Dose and formulation of Na-APR-1 that generates the highest IgG antibody response at Day 126 (14 days after final vaccination), as determined by an indirect enzyme-linked immunosorbent assay (ELISA). | 14 days after final vaccination | 
| B cell response to Na-APR-1 | Dose and formulation of the Na-APR-1 (M74) vaccine that results in the highest production of Na-APR-1 (M74) specific B cells and subtypes (memory or plasma). | Study Days 14, 70, 126, 140 and 290 | 
| Exploratory cellular immune response to Na-APR-1 | Exploratory studies of the cellular immune responses to the Na APR-1 (M74) antigen both before and after immunization. | Study Days 14, 70, 126, 140 and 290 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Human Hookworm, Necator americanus, Hookworm, Hookworm Disease, Iron-deficiency anemia, Soil-transmitted helminth infection, Neglected Tropical Disease, Na-APR-1