A Phase 1 interventional study of Na-GST-1/Alhydrogel® and CpG 10104 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 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-07-04.
Sponsored by Baylor College of Medicine · Phase 1, Interventional, and Prevention
Na-GST-1 is a protein expressed during the adult stage of the hookworm life cycle that is thought to play a role in the parasite's degradation of host hemoglobin for use as an energy source. Vaccination with recombinant GST-1 has protected dogs and hamsters from infection in challenge studies. This study will evaluate the safety and immunogenicity of two formulations of Na-GST-1 in healthy adult volunteers when co-administered with the immunostimulant CpG 10104, a Toll-like Receptor-9 agonist.
This is a Phase 1 randomized double-blind dose-escalation clinical trial in healthy hookworm-naïve adults conducted at the George Washington Medical Faculty Associates, Washington, DC, and the George Washington University School of Medicine and Health Sciences, Department of Microbiology, Immunology and Tropical Medicine, Washington, DC. In total, 24 subjects will be progressively enrolled into 2 cohorts of 12 subjects each. In the first cohort 8 subjects will receive 30µg Na-GST-1/Alhydrogel co-administered with 500µg CpG 10104 and 4 subjects will receive 100µg Na-GST-1/Alhydrogel® only, in a randomized, double-blinded fashion. In the second cohort 8 subjects will receive 100µg Na-GST-1/Alhydrogel co-administered with 500µg CpG 10104 and 4 volunteers will receive 100µg Na-GST-1/Alhydrogel only, in a randomized, double-blinded fashion. Vaccinations will be administered intramuscularly in the deltoid muscle according to a 0, 2, 4-month schedule. Each subject will participate in the study for 68 weeks (16 months) and the total duration of the study is estimated at approximately 19 months.
39 studies on the registry are indexed under Hookworm Infections; 5 are open to participants now.
This study's enrollment of 24 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.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
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).
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.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
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.
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.
High Dose Na-GST-1/Alhydrogel® Only
Biological: Na-GST-1/Alhydrogel®
Low Dose Na-GST-1/Alhydrogel® Plus 500 µg CpG 10104
Biological: Na-GST-1/Alhydrogel® · Biological: CpG 10104
High Dose Na-GST-1/Alhydrogel® Plus 500 µg CpG 10104
Biological: Na-GST-1/Alhydrogel® · Biological: CpG 10104
The Na-GST-1 candidate vaccine contains the recombinant Na-GST-1 protein expressed by Pichia pastoris. Purified Na-GST-1 was subsequently adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10% glucose and 10 mM imidazole. The final concentration of Na-GST-1 in the drug product is 0.1 mg/ml whereas that of Alhydrogel® is 0.8 mg/ml. Different doses of Na-GST-1 will be delivered by injecting different volumes of the 0.1 mg/ml Na-GST-1 preparation.
Also known as: Na-GST-1, Necator americanus glutathione S-transferase-1
Unmethylated cytosine-guanine dinucleotides (CpGs) are found in bacterial DNA in the expected frequency predicted by random usage, whereas their occurrence is suppressed 4-fold in vertebrate DNA. In vertebrate DNA CpG motifs are also usually methylated. Bacterial CpG-DNA motifs are recognized by the human innate immune system via Toll-like Receptor-9 (TLR-9), a pathogen-associated molecular pattern (PAMP) receptor that is expressed, in particular, by antigen-presenting dendritic cells. Interactions between CpG-DNA and TLR9 rapidly activate antigen-presenting dendritic cells to upregulate co-stimulatory molecules and to produce Th1-polarizing cytokines such as interleukin-12 and interferon gamma. CpG 10104 is a short synthetic oligodeoxynucleotide of the following sequence: 5'-TCG TCG TTT CGT CGT TTT GTC GTT-3'.
Also known as: Cytosine-phosphate-Guanine oligodeoxynucleotide, CpG ODN 101014, CpG ODN
Vaccine-related Adverse Events
The frequency of immediate, systemic, and local injection site adverse events, graded by severity, for Na-GST-1/Alhydrogel administered alone or in combination with CpG 10104
Time frame: Up to study day 470
IgG Antibody Response to Na-GST-1 on Study Day 126
Dose and formulation of Na-GST-1 that generates the highest IgG antibody response at Day 126 (14 days after final vaccination), as determined by a qualified indirect enzyme-linked immunosorbent assay (ELISA) and measured in Arbitrary Units (AU) that are interpolated from a standard reference curve formulated by serial dilutions of a serum pool derived from known high responders in previous clinical trials of this antigen. This ELISA has not been validated and does not report mass units since these have not yet been defined. Reporting ELISA values in AU is an accepted practice early in clinical development before full assay validation and quantification of mass units.
Time frame: 14 days after final vaccination
Exploratory Cellular Immune Response to Na-GST-1
Exploratory studies of the cellular immune responses to the Na-GST-1 antigen both before and after immunization.
Time frame: Up to study day 290
| Milestone | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|
| Started | 8 | 8 | 8 |
| Completed | 8 | 6 | 7 |
| Not completed | 0 | 2 | 1 |
The frequency of immediate, systemic, and local injection site adverse events, graded by severity, for Na-GST-1/Alhydrogel administered alone or in combination with CpG 10104
| Participants | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|
| Number of participants with an immediate AE | 1 | 3 | 0 |
| Number of participants with a systemic AE | 3 | 4 | 5 |
| Number of participants with an injection site AE | 7 | 8 | 7 |
Dose and formulation of Na-GST-1 that generates the highest IgG antibody response at Day 126 (14 days after final vaccination), as determined by a qualified indirect enzyme-linked immunosorbent assay (ELISA) and measured in Arbitrary Units (AU) that are interpolated from a standard reference curve formulated by serial dilutions of a serum pool derived from known high responders in previous clinical trials of this antigen. This ELISA has not been validated and does not report mass units since these have not yet been defined. Reporting ELISA values in AU is an accepted practice early in clinical development before full assay validation and quantification of mass units.
| Arbitrary Units/mL | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|
| IgG Antibody Response to Na-GST-1 on Study Day 126 | 49.42 (17.07 to 143.0) | 300.7 (194.6 to 464.8) | 389.5 (212.8 to 713.0) |
Exploratory studies of the cellular immune responses to the Na-GST-1 antigen both before and after immunization.
No measurements were reported for this outcome.
Collected over Participants were followed for approximately 68 weeks, or 16 months. This includes following participants for approximately 12 months after receiving the third vaccination.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| 100 µg Na-GST-1/Alhydrogel | 0/8 (0%) | 0/8 (0%) | 8/8 (100%) |
| 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 0/8 (0%) | 0/8 (0%) | 8/8 (100%) |
| 100 µg Na-GST-1/Alhydrogel + CpG 10104 | 0/8 (0%) | 0/8 (0%) | 8/8 (100%) |
| Event | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|
| Injection site painGeneral disorders | 7/8 | 8/8 | 7/8 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 1/8 | 2/8 | 6/8 |
| Upper respiratory tract infectionInfections and infestations | 4/8 | 5/8 | 6/8 |
| HeadacheNervous system disorders | 5/8 | 5/8 | 5/8 |
| MyalgiaMusculoskeletal and connective tissue disorders | 1/8 | 3/8 | 5/8 |
| NauseaGastrointestinal disorders | 1/8 | 1/8 | 4/8 |
| Abdominal PainGastrointestinal disorders | 0/8 | 3/8 | 1/8 |
| CoughRespiratory, thoracic and mediastinal disorders | 0/8 | 3/8 | 1/8 |
| FatigueGeneral disorders | 0/8 | 1/8 | 3/8 |
| Systolic hypertensionVascular disorders | 0/8 | 3/8 | 2/8 |
| Age, Categorical(Participants) | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|
| <=18 years | 0 | 0 | 0 | 0 |
| Between 18 and 65 years | 8 | 8 | 8 | 24 |
| >=65 years | 0 | 0 | 0 | 0 |
| Age, Continuous(years) | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|
| Median | 26.5 (24.75 to 30.5) | 31.0 (26.0 to 45) | 32 (28.5 to 41.75) | 29 (25.5 to 41.75) |
| Sex: Female, Male(Participants) | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|
| Female | 5 | 2 | 3 | 10 |
| Male | 3 | 6 | 5 | 14 |
| Race (NIH/OMB)(Participants) | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 |
| Asian | 2 | 0 | 0 | 2 |
| Native Hawaiian or Other Pacific Islander | 0 | 1 | 0 | 1 |
| Black or African American | 1 | 5 | 4 | 10 |
| White | 5 | 1 | 4 | 10 |
| More than one race | 0 | 1 | 0 | 1 |
| Unknown or Not Reported | 0 | 0 | 0 | 0 |
| Region of Enrollment(participants) | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|
| United States | 8 | 8 | 8 | 24 |
The record gives a start of Oct 2014, a primary completion of Jun 2016 and a completion of Oct 2016. It does not say whether these dates are actual or estimated.
Results were first posted in Jul 2025, 9 years 1 month after primary completion.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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