ClinicalTrials.gg
TerminatedNCT00473967Updated Jul 9, 2012

Phase 1 Trial of Na-ASP-2 Hookworm Vaccine in Previously Infected Brazilian Adults

A Phase 1 interventional study of Na-ASP-2 Hookworm Vaccine in Hookworm Infection, sponsored by Albert B. Sabin Vaccine Institute. Terminated at 1 site in Brazil. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2012-07-09.

Sponsored by Albert B. Sabin Vaccine Institute · Phase 1, Interventional, and Prevention

Why this study was terminated
Occurrence of unacceptable adverse events.
Phase
Phase 1
Study type
Interventional
Enrollment
9
Allocation
Randomized
Ages
18 Years to 45 Years
Sex
All
01

Study summary

Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. Vaccination with recombinant ASP-2 has protected dogs and hamsters from infection in challenge studies. In a clinical study in hookworm-uninfected adults in the USA, Na-ASP-2 Hookworm Vaccine was safe and immunogenic. This study will evaluate its safety and immunogenicity in individuals living in an area of endemic hookworm infection.

Read the detailed description
  • Double-blind, randomized, controlled Phase 1 clinical trial.
  • Study site: Americaninhas, Minas Gerais, Brazil.
  • Number of participants: 48 in three groups of 16, randomized to receive either Na-ASP-2 Hookworm Vaccine (n=36) or Butang® hepatitis B vaccine (n=12).
  • Study duration: 48 weeks; each participant will be followed for a total of 42 weeks.
  • Immunization schedule: Study days 0, 56 and 112.
  • Route: IM in the deltoid muscle.
  • Dose of Na-ASP-2: 10, 50 and 100 µg for the first, second and third dose cohort, respectively.
  • Dose of Alhydrogel®: 800 µg for each dose of Na-ASP-2.
02

Conditions studied

  • Hookworm Infection

Keywords

  • Vaccine
  • Hookworm
  • Phase 1
  • Na-ASP-2
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 9 is below the median of 182 across 36 interventional studies indexed under Hookworm Infections.

Browse Hookworm Infections studies →

Lead sponsor

Albert B. Sabin Vaccine Institute is the lead sponsor of 11 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 45 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 45 years, inclusive.
  • Known residents of the Municipality of Novo Oriente de Minas, Minas Gerais, Brazil.
  • Good general health as determined by means of the screening procedure.
  • Completed a 3-dose albendazole treatment for documented hookworm infection during the previous 3 months.
  • Available for the duration of the trial (42 weeks).
  • Willingness to participate in the study as evidenced by signing the document.

Exclusion criteria

Exclusion Criteria:

  • Pregnancy as determined by a positive urine β-hCG (if female).
  • Participant unwilling to use reliable methods up until one month following the third immunization (if female).
  • Currently lactating and breast-feeding (if female).
  • Inability to correctly answer all questions on the comprehension questionnaire.
  • Evidence of neurologic, cardiac, pulmonary, hepatic, rheumatologic, , or renal disease by history, physical examination, and/or laboratory studies.
  • Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the volunteer to understand and cooperate with the study protocol.
  • Laboratory evidence of liver disease ( [ALT] greater than 64 U/l [females] or greater than 58 U/l [males]).
  • Laboratory evidence of renal disease (serum creatinine greater than 1.1 mg/dl [females] or greater than 1.3 mg/dl [males], or more than trace protein or blood on urine dipstick testing).
  • Laboratory evidence of hematologic disease (absolute leukocyte count \<3000/mm3 or >12.5 x 103/mm3; \<10.3 g/dl [females] or \<11.0 g/dl [males]; absolute lymphocyte count \<900/mm3; or count \<120,000/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.
  • 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 regular use of inhalers or emergency clinic visit or hospitalization within the last 6 months.
  • Positive ELISA for .
  • Positive ELISA for .
  • Known immunodeficiency syndrome.
  • Use of (excluding topical or nasal) or drugs within 30 days of starting this 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 past 6 months.
  • Previous receipt of a primary series of any hepatitis B vaccine.
  • History of allergy to yeast.
Terms in these criteria, in plain language(13)

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.

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.

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
Single group
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
9 participants (actual)

Study arms

  • Experimental
    10 mcg Na-ASP-2/Alhydrogel

    Na-ASP-2 Hookworm Vaccine

    Biological: Na-ASP-2 Hookworm Vaccine

  • Active comparator
    Butang hepatitis B vaccine

    Hepatitis B Vaccine - comparator vaccine

    Biological: Na-ASP-2 Hookworm Vaccine

Interventions

  • BiologicalNa-ASP-2 Hookworm Vaccine

    Injections of one of three different dose concentrations of the Na-ASP-2 vaccine (10, 50, or 100 mcg) vs. the hepatitis B vaccine, delivered at 0, 2, and 4 months by intramuscular injection.

06

What researchers measure

Primary outcomes

  1. To determine the frequency of vaccine-related adverse events, graded by severity, for each dose of the Na-ASP-2 Hookworm Vaccine

    Time frame: For the duration of the study

Secondary outcomes

  1. To determine the dose of Na-ASP-2 that generates the highest antibody response as determined by an indirect enzyme-linked immunosorbent assay (ELISA)

    Time frame: 2 weeks after the third injection

  2. To assess and compare the duration of antibody response to Na-ASP-2

    Time frame: For the duration of the study

  3. To perform exploratory studies of the cellular immune responses to the Na-ASP-2 antigen both before and after immunization

    Time frame: For the duration of the study

07

Study locations

1 site
  • Centro de Pesquisas Rene Rachou
    Belo Horizonte, Brazil
08

References and documents

Publications

  • Diemert DJ, Pinto AG, Freire J, Jariwala A, Santiago H, Hamilton RG, Periago MV, Loukas A, Tribolet L, Mulvenna J, Correa-Oliveira R, Hotez PJ, Bethony JM. Generalized urticaria induced by the Na-ASP-2 hookworm vaccine: implications for the development of vaccines against helminths. J Allergy Clin Immunol. 2012 Jul;130(1):169-76.e6. doi: 10.1016/j.jaci.2012.04.027. Epub 2012 May 26. PubMed 22633322 ↗
09

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of May 2007, a primary completion of Mar 2008 and a completion of Mar 2009. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
May 14, 2007
First posted
May 16, 2007
Start
May 2007
Primary completionActual
Mar 2008
CompletionActual
Mar 2009
Last update
Jul 9, 2012
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jul 9, 2012, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT00473967
Lead sponsor
Albert B. Sabin Vaccine Institute
Responsible party
Sponsor
First posted
May 16, 2007
Start date
May 2007
Primary completion
Mar 2008
Completion
Mar 2009
Last update
Jul 9, 2012

Study contacts

David J Diemert, MD
principal investigator · Albert B. Sabin Vaccine Institute

Oversight

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

Not currently enrolling

This study is terminated, as verified in Jul 2012. You cannot join it, but the record below documents what was studied.

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