A Phase 1 interventional study of 10 μg Na-GST-1/Alhydrogel and 30 μg Na-GST-1/Alhydrogel in Hookworm Infection and Hookworm Disease, sponsored by Baylor College of Medicine. Completed at 1 site in United States. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-01-06.
Sponsored by Baylor College of Medicine · Phase 1, Interventional, and Prevention
This study is designed to evaluate the safety, reactogenicity, and immunogenicity of Na-GST-1 adsorbed to Alhydrogel® with or without two different dose concentrations of a novel adjuvant, GLA-AF (1 µg or 5 μg) among healthy adult volunteers.
Human hookworm infection is a soil-transmitted helminth infection caused by the nematode parasites Necator americanus and Ancylostoma duodenale. It is one of the most common chronic infections of humans, afflicting up to 740 million people in the developing nations of the tropics. The largest number of cases occurs in impoverished rural areas of sub-Saharan Africa, Southeast Asia, China, and the tropical regions of the Americas. Approximately 3.2 billion people are at risk for hookworm infection in these areas. N. americanus is the most common hookworm worldwide, whereas A. duodenale is more geographically restricted.
The primary approach to hookworm control worldwide has been the frequent and periodic mass administration of benzimidazole anthelminthics to school-aged children living in high-prevalence areas. In 2001, the World Health Assembly adopted Resolution 54.19 which urges member states to provide regular anthelminthic treatment to high-risk groups with the target of regular treatment of at least 75% of all at-risk school-aged children. However, the cure rates for a single dose of a benzimidazole varies with rates as low as 61% (400 mg) and 67% (800 mg) for albendazole and 19% (single dose) and 45% (repeated dose) for mebendazole being reported. These concerns have prompted interest in developing alternative tools for hookworm control. Vaccination to prevent the anemia associated with moderate and heavy intensity hookworm infection would alleviate the public health deficiencies of drug treatment alone.
The current strategy for development of Human Hookworm candidate vaccines is focused on antigens expressed during the adult stage of the hookworm life cycle which play a role in digesting the host hemoglobin, used by the worm as an energy source. These antigens are relatively hidden from the human immune system during natural infection, and hence have a low likelihood of inducing antigen-specific IgE in exposed/infected individuals, reducing the potential for allergic reaction upon vaccination.
The nutritional and metabolic requirements of the adult hookworm living in the human intestine are dependent upon degradation of host hemoglobin that has been ingested by the worm. N. americanus hookworms depend on host hemoglobin for survival. Following hemolysis, adult hookworms use an ordered cascade of hemoglobinases to cleave hemoglobin into smaller molecules. Following hemoglobin digestion, the freed heme generates toxic oxygen radicals that can be bound and detoxified by molecules such as glutathione S-transferase-1 (GST-1). GST-1 of N. americanus (Na-GST-1) is a critical enzyme that plays a role in parasite blood feeding; when used as a vaccine, the investigators hypothesize that the antigen will induce anti-enzyme neutralizing antibodies that will interfere with parasite blood-feeding and cause parasite death or reduce worm fecundity.
Following its selection as a candidate antigen Na-GST-1 has been successfully manufactured and tested in the laboratory and in animals with both Alhydrogel® (aluminum hydroxide suspension)and Alhydrogel® plus Gluco-Pyranosylphospho-Lipid A Aqueous Formulation (GLA-AF). Na-GST-1 has been shown to be pure, potent, and stable when administered as either of these two formulations.
Although GLA-AF has not yet been administered to humans, an oil-in-water emulsion of GLA (GLA-SE) has been used in combination with the Fluzone® trivalent killed influenza vaccine in a Phase 1 trial. In this study, doses up to 1 µg of GLA-SE were safe and well-tolerated and significantly enhanced influenza-specific antibody responses.
The phase 1 trial described here will enroll healthy adults who have not been infected with or exposed to hookworm who are living in the Washington DC area. A phase 1 trial of Na-GST-1/Alhydrogel (with or without GLA-AF) is planned to start in July 2011 in Brazil. In that study, both hookworm-naïve and hookworm-exposed healthy adults will be vaccinated with either Na-GST-1/Alhydrogel®, Na-GST-1/Alhydrogel® co-administered with 1 µg GLA-AF, or the Butang® hepatitis B vaccine. The objectives of that study will be to assess the safety and immunogenicity of the Na-GST-1 formulations in healthy Brazilian adults. The study described here will complement the study in Brazilian adults as it will provide additional information about different dose concentrations of GLA-AF as well as detailed data on the humoral immune response to the different formulations that will be tested.
In this study, 90 volunteers will be progressively enrolled into one of six dose cohorts. Dose cohorts will be enrolled and vaccinated in a consecutive fashion. The 15 volunteers in each cohort will be subsequently randomized in a 1:2 ratio to receive either the Na-GST-1/Alhydrogel® (n=5) or Na-GST-1/Alhydrogel®/GLA-AF (n=10). In the first, third and fifth cohorts, volunteers will be randomized to receive either Na-GST-1/Alhydrogel® (n=5) OR Na-GST-1/Alhydrogel® co-administered with 1 µg GLA-AF (n=10), while in the second, fourth, and sixth cohorts, volunteers will be randomized to receive either Na-GST-1/Alhydrogel® (n=5) or Na-GST-1/Alhydrogel® co-administered with 5 µg GLA-AF (n=10).
Each participant will receive 3 doses of the assigned study agent given in 56 day intervals (i.e. Day 0, Day 56 and Day 112). The trial is expected to last for approximately 18 months. Each participant will be followed for 16 months from the time of the first injection.
Safety parameters will be monitored throughout the study. The primary endpoint for the study will be measurement of antigen-specific antibody response.
39 studies on the registry are indexed under Hookworm Infections; 5 are open to participants now.
This study's enrollment of 40 is below the median of 182 across 36 interventional studies indexed under Hookworm Infections.
Browse Hookworm Infections studies →Baylor College of Medicine is the lead sponsor of 747 studies on the registry; 110 are open to participants now.
Of its 84 completed or terminated interventional studies of FDA-regulated products, 45 (54%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
10 μg Na-GST-1/Alhydrogel vs. 10 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg)
Biological: 10 μg Na-GST-1/Alhydrogel · Biological: 10 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg)
30 μg Na-GST-1/Alhydrogel vs. 30 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg)
Biological: 30 μg Na-GST-1/Alhydrogel · Biological: 30 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg)
30 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg)
Biological: 30 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg)
100 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg)
Biological: 100 μg Na-GST-1/Alhydrogel
100 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg)
Biological: 100 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg)
3 doses 10 μg Na-GST-1/Alhydrogel administered at 56 day intervals
3 doses 30 μg Na-GST-1/Alhydrogel administered at 56 day intervals
3 doses 100 μg Na-GST-1/Alhydrogel administered at 56 day intervals
3 doses 10 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg) administered at 56 day intervals
3 doses of 30 μg Na-GST-1/Alhydrogel/GLA-AF (1 μg) administered at 56 day intervals
3 doses 30 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg) administered at 56 day intervals
3 doses 100 μg Na-GST-1/Alhydrogel/GLA-AF (5 μg) administered at 56 day intervals
Immediate Vaccine Related Adverse Events
Frequency of vaccine-related AEs, graded by severity, for each dose and formulation of Na-GST-1
Time frame: 2 hours post vaccination
IgG Antibody Response to Na-GST-1
Dose and formulation of Na-GST-1 that generates the highest IgG antibody response at Day 126, as determined by an indirect enzyme-linked immunosorbent assay (ELISA)
Time frame: 126 days post dose 1
| Milestone | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 |
|---|---|---|---|---|---|
| Started | 12 | 12 | 4 | 4 | 8 |
| Completed | 11 | 11 | 4 | 3 | 6 |
| Not completed | 1 | 1 | 0 | 1 | 2 |
Frequency of vaccine-related AEs, graded by severity, for each dose and formulation of Na-GST-1
| Participants | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 |
|---|---|---|---|---|---|
| Immediate Vaccine Related Adverse Events | 4 | 1 | 0 | 1 | 4 |
Dose and formulation of Na-GST-1 that generates the highest IgG antibody response at Day 126, as determined by an indirect enzyme-linked immunosorbent assay (ELISA)
| Arbitrary Units | 10 μg Na-GST-1/Alhydrogel | 10 µg Na-GST-1/Alhydrogel/GLA-AF (1 µg) | 30 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel/GLA-AF (1 µg) | 30 µg Na-GST-1/Alhydrogel/GLA-AF (5 µg) | 100 µg Na-GST-1/Alhydrogel | 100 µg Na-GST-1/Alhydrogel/GLA-AF (5 µg) |
|---|---|---|---|---|---|---|---|
| IgG Antibody Response to Na-GST-1 | 17.12 ± 24.11 | 210.02 ± 366.67 | 66.86 ± 105.60 | 64.65 ± 74.86 | 69.34 ± 107.46 | 117.24 ± 117.99 | 89.42 ± 97.80 |
Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Cohort 1 | — | 0/12 (0%) | 12/12 (100%) |
| Cohort 2 | — | 0/12 (0%) | 12/12 (100%) |
| Cohort 3 | — | 0/4 (0%) | 4/4 (100%) |
| Cohort 4 | — | 0/4 (0%) | 4/4 (100%) |
| Cohort 5 | — | 1/8 (12.5%) | 8/8 (100%) |
| Event | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 |
|---|---|---|---|---|---|
| Delusional EpisodePsychiatric disorders | 0/12 | 0/12 | 0/4 | 0/4 | 1/8 |
| Event | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 |
|---|---|---|---|---|---|
| Injection Site PainGeneral disorders | 6/12 | 4/12 | 3/4 | 1/4 | 5/8 |
| Injection Site TendernessGeneral disorders | 4/12 | 5/12 | 3/4 | 2/4 | 4/8 |
| HeadacheNervous system disorders | 8/12 | 7/12 | 2/4 | 1/4 | 1/8 |
| Injection Site SwellingGeneral disorders | 1/12 | 0/12 | 1/4 | 2/4 | 2/8 |
| Injection Site ErythemaGeneral disorders | 0/12 | 0/12 | 0/4 | 0/4 | 2/8 |
| NauseaGastrointestinal disorders | 3/12 | 2/12 | 1/4 | 0/4 | 2/8 |
| VomitingGastrointestinal disorders | 1/12 | 1/12 | 0/4 | 1/4 | 1/8 |
| UrticariaImmune system disorders | 0/12 | 0/12 | 0/4 | 1/4 | 0/8 |
| MyalgiaMusculoskeletal and connective tissue disorders | 1/12 | 2/12 | 0/4 | 0/4 | 0/8 |
| ArthrlagiaMusculoskeletal and connective tissue disorders | 0/12 | 1/12 | 0/4 | 0/4 | 0/8 |
| Age, Continuous(years) | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 | Total |
|---|---|---|---|---|---|---|
| Mean | 34.3 (18 to 45) | 33.8 (18 to 45) | 26.3 (18 to 33) | 23.3 (18 to 39) | 35.0 (26 to 45) | 32.9 (18 to 45) |
| Sex: Female, Male(Participants) | Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | Cohort 5 | Total |
|---|---|---|---|---|---|---|
| Female | 4 | 5 | 1 | 1 | 5 | 16 |
| Male | 8 | 7 | 3 | 3 | 3 | 24 |
This study is completed, as verified in Jan 2025. You cannot join it, but the record below documents what was studied.
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