ClinicalTrials.gg
CompletedNCT02126462Updated May 31, 2017

Safety and Immunogenicity of Co-Administered Hookworm Vaccine Candidates Na-GST-1 and Na-APR-1 in Gabonese Adults

A Phase 1 interventional study of Na-APR-1 (M74)/Alhydrogel® and Na-GST-1/Alhydrogel® in Hookworm Infection and Hookworm Disease, sponsored by Baylor College of Medicine. Completed at 1 site in Gabon. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-05-31.

Sponsored by Baylor College of Medicine · Phase 1, Interventional, and Prevention

Phase
Phase 1
Study type
Interventional
Enrollment
32
Allocation
Randomized
Ages
18 Years to 50 Years
Sex
All
01

Study summary

Na-GST-1 and Na-APR-1 are proteins expressed during the adult stage of the Necator americanus hookworm life cycle that are thought to play a role in the parasite's degradation of host hemoglobin for use as an energy source. Vaccination with recombinant GST-1 or APR-1 has protected dogs and hamsters from infection in challenge studies. This study will evaluate the safety and immunogenicity of co-administering Na-GST-1 and Na-APR-1 to healthy Gabonese adults living in an area of endemic hookworm infection.

Read the detailed description

Double-blind, randomized, controlled dose-escalation Phase 1 clinical trial in hookworm exposed adults.

Study site: Centre de Recherches Médicales de Lambaréné Number of participants: 32 in 2 cohorts of 16

Doses of Na-GST-1 to be tested: 30 and 100 μg Doses of Na-APR-1 to be tested: 30 and 100 μg Dose of GLA-AF: 5 μg per antigen

Cohort 1: 30 μg of each of the two antigens (Na-GST-1/Alhydrogel® and Na-APR-1 (M74)/Alhydrogel®) or hepatitis B vaccine; Cohort 2: 100 μg of each of the two antigens (Na-GST- 1/Alhydrogel® and Na-APR-1 (M74) /Alhydrogel®) or hepatitis B vaccine.

Randomization: Cohort 1: 30 μg Na-GST-1 + 30 μg Na-APR-1 (M74) (n = 12) versus Hepatitis B Vaccine/placebo (n = 4) Cohort 2: 100 μg Na-GST-1 + 100 μg Na-APR-1 (M74) (n = 12) versus Hepatitis B Vaccine + placebo (n = 4)

The cohorts will be enrolled in a staggered fashion with safety data assessed prior to the Na-GST-1 and Na-APR-1 dose escalation from 30 to 100 µg.

Pre-treatment: Albendazole (400 mg) at least 2 weeks prior to first vaccination

Immunization schedule: Study days 0, 28 and 180 Route: Intramuscular in the deltoid muscle

Study duration: approximately 20 months; each participant will be followed for a total of 12 months.

02

Conditions studied

  • Hookworm Infection
  • Hookworm Disease

Keywords

  • Human Hookworm
  • Necator americanus
  • Hookworm
  • Hookworm Disease
  • Iron-deficiency anemia
  • Soil-transmitted helminth infection
  • Neglected Tropical Disease
  • Na-APR-1
  • Na-GST-1
03

In context

Hookworm Infections

39 studies on the registry are indexed under Hookworm Infections; 5 are open to participants now.

This study's enrollment of 32 is below the median of 182 across 36 interventional studies indexed under Hookworm Infections.

Browse Hookworm Infections studies →

Lead sponsor

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.

04

Who can participate

Ages eligible
18 Years to 50 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

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.

Inclusion criteria

  • Males or females between 18 and 50 years, inclusive, who are long-term residents of Gabon.
  • Good general health as determined by means of the screening procedure.
  • Assumed availability for the duration of the trial (12 months).
  • Willingness to participate in the study as evidenced by signing the document.
  • Negative for hookworm during screening, or if found to be infected with hookworm, has completed a course of three doses of albendazole.

Exclusion criteria

Exclusion Criteria:

  • Pregnancy as determined by a positive urine hCG (if female).
  • Participant unwilling to use reliable up until one month following the third immunization (if female and not surgically sterile, abstinent or at least 2 years ).
  • Currently lactating and breast-feeding (if female).
  • Inability to correctly answer all questions on the comprehension questionnaire.
  • Evidence of neurologic, cardiac, pulmonary, hepatic, rheumatologic, , diabetes, or renal disease by history, physical examination, and/or laboratory studies.
  • Known or suspected immunodeficiency.
  • Laboratory evidence of liver disease ( [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 (absolute leukocyte count \<3500/mm3; absolute leukocyte count >11.0 x 103/mm3; \<10.000 g/dl [females] or \<12.0 g/dl [males]; or, count \<140,000/mm3).
  • 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 vaccine or drug trial within 30 days of starting this study or for the duration of the 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 room/clinic visit or hospitalization within 6 months of the volunteer's planned first vaccination in the study.
  • Positive for
  • Positive ELISA for .
  • Positive for infection
  • Use of (excluding topical or nasal) or drugs within 30 days of starting this study or expect to use for the duration of the study.
  • Receipt of a within past 4 weeks or a killed vaccine within past 2 weeks prior to entry into the study.
  • History of a surgical splenectomy.
  • Receipt of blood products within the 6 months prior to entry into the study.
  • Previous receipt of a primary series of any hepatitis B vaccine.
Terms in these criteria, in plain language(15)

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.

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.

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.

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).

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

05

Study design

Phase
Phase 1
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
32 participants (actual)

Study arms

  • Experimental
    30 µg Na-GST-1 + 30 µg Na-APR-1 (M74)

    30 µg Na-GST-1/Alhydrogel plus 5 µg GLA-AF co-administered with 30 µg Na-APR-1 (M74)/Alhydrogel plus 5 µg GLA-AF

    Biological: Na-APR-1 (M74)/Alhydrogel® · Biological: Na-GST-1/Alhydrogel®

  • Active comparator
    Hepatitis B vaccine

    Hepatitis B vaccine co-administered with saline

    Biological: Hepatitis B vaccine

  • Experimental
    100 µg Na-GST-1 plus 100 µg Na-APR-1 (M74)

    100 µg Na-GST-1/Alhydrogel plus 5 µg GLA-AF co-administered with 100 µg Na-APR-1 (M74)/Alhydrogel plus 5 µg GLA-AF

    Biological: Na-APR-1 (M74)/Alhydrogel® · Biological: Na-GST-1/Alhydrogel®

Interventions

  • BiologicalNa-APR-1 (M74)/Alhydrogel®
  • BiologicalNa-GST-1/Alhydrogel®
  • BiologicalHepatitis B vaccine

    Hepatitis B vaccine co-administered with saline

06

What researchers measure

Primary outcomes

  1. Vaccine-related Adverse Events

    To estimate the frequency of vaccine-related adverse events, graded by severity, for each dose of co-administered Na-GST-1 and Na-APR-1 (M74). 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 1, 3, 7, 14, and 28 days following each vaccination.

    Time frame: Day 360

Secondary outcomes

  1. IgG response to Na-GST-1 and Na-APR-1 (M74)

    To determine the doses of Na-GST-1 and Na-APR-1 (M74) that generate the highest IgG antibody responses at Day 194, as determined by indirect enzyme-linked immunosorbent assays (ELISA)

    Time frame: Day 194

  2. Duration of antibody response to Na-GST-1 and Na-APR-1 (M74)

    To assess and compare the duration of antibody responses to Na- GST-1 and Na-APR-1 (M74).

    Time frame: Day 14, 28, 42, 56, 180, 194, 208, 270, 360

  3. Exploratory studies of memory B-cell responses

    Exploratory studies of memory B-cell responses against the metabolomics changes before and after Na-GST-1 and NA-APR-1 (M74) vaccine antigens.

    Time frame: Days 14, 28, 42, 56, 180, 194, 208, 270, 360

07

Study locations

1 site
  • Centre de Recherches Médicales de Lambaréné Albert Schweitzer Hospital
    Lambaréné, BP: 118, Gabon
08

References and documents

Publications

  • Mouwenda YD, Betouke Ongwe ME, Sonnet F, Stam KA, Labuda LA, De Vries S, Grobusch MP, Zinsou FJ, Honkpehedji YJ, Dejon Agobe JC, Diemert DJ, van Leeuwen R, Bottazzi ME, Hotez PJ, Kremsner PG, Bethony JM, Jochems SP, Adegnika AA, Massinga Loembe M, Yazdanbakhsh M. Characterization of T cell responses to co-administered hookworm vaccine candidates Na-GST-1 and Na-APR-1 in healthy adults in Gabon. PLoS Negl Trop Dis. 2021 Oct 1;15(10):e0009732. doi: 10.1371/journal.pntd.0009732. eCollection 2021 Oct. PubMed 34597297 ↗
  • Adegnika AA, de Vries SG, Zinsou FJ, Honkepehedji YJ, Dejon Agobe JC, Vodonou KG, Bikangui R, Bouyoukou Hounkpatin A, Bache EB, Massinga Loembe M, van Leeuwen R, Molemans M, Kremsner PG, Yazdanbakhsh M, Hotez PJ, Bottazzi ME, Li G, Bethony JM, Diemert DJ, Grobusch MP; HookVac Consortium. Safety and immunogenicity of co-administered hookworm vaccine candidates Na-GST-1 and Na-APR-1 in Gabonese adults: a randomised, controlled, double-blind, phase 1 dose-escalation trial. Lancet Infect Dis. 2021 Feb;21(2):275-285. doi: 10.1016/S1473-3099(20)30288-7. Epub 2020 Sep 11. PubMed 32926834 ↗

Individual participant data

Plan to share: Undecided

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 31, 2017, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02126462
Responsible party
Maria Elena Bottazzi PhD (Sponsor, Baylor College of Medicine) — Principal investigator
First posted
Apr 30, 2014
Start date
Nov 2014
Primary completion
Feb 2016
Completion
Jun 2016
Last update
May 31, 2017

Study contacts

Ayola Adegnika, MD
principal investigator · Centre de Recherches Medicales de Lambarené

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in May 2017. You cannot join it, but the record below documents what was studied.

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