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Not yet recruitingNCT06478498HiBiSkiUpdated Jul 12, 2024

Immune Responses in the Skin After Hookworm Infection

An interventional study of Necator americanus L3 larvae in Necator Americanus Infection, sponsored by Leiden University Medical Center. Not yet recruiting at 1 site in Netherlands. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-07-12.

Sponsored by Leiden University Medical Center · Not applicable, Interventional, and Other

From the registry’s dates

  • Primary completion was expected by Jan 2025, 1 year 9 months ago, but the record still lists the study as not yet recruiting.
Phase
Not applicable
Study type
Interventional
Enrollment
5
Allocation
Non-randomized
Ages
18 Years to 45 Years
Sex
All
01

Study summary

Five healthy volunteers will be repeatedly exposed to L3 Necator americanus larvae after which two skin biopsies will be taken. Three of the volunteers will be treated two weeks after each infection after which the study will end after 13 weeks. Two of the volunteers will retain the infection for up to two years and will be asked to donate stool samples.

Read the detailed description

Five volunteers will be exposed to 50 Necator americanus L3 larvae, after which they will be treated with a curative regimen of albendazole after two weeks. Then, they will be inoculated with a lower dose of 10 L3 larvae concentrated on one spot, followed by two skin biopsies (one at the inoculation site, the other one serving as a negative control). Subsequently, participants will be treated with albendazole at week 5, except for the participants who have volunteered to become chronic donors. For chronic donors, patency of infection will be assessed and infections repeated (max dose 50 L3 larvae at one time) until egg outputs are >1500 eggs per gram (epg) at the start of the donor phase. If necessary, top-up inoculations can be performed in the donor phase as well when the egg-output is too low for the requested experiments.

02

Conditions studied

  • Necator Americanus Infection

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Keywords

  • Controlled human infection model
  • hookworm
  • immune responses
  • skin
03

In context

Ancylostomiasis

38 studies on the registry are indexed under Ancylostomiasis; 2 are open to participants now.

This study's planned enrollment of 5 is below the median of 87 across 37 interventional studies indexed under Ancylostomiasis.

Browse Ancylostomiasis studies →

Lead sponsor

Leiden University Medical Center is the lead sponsor of 333 studies on the registry; 109 are 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

In order to be eligible to participate in this study, a subject must meet all of the following criteria:

  1. Subject is aged ≥ 18 and ≤ 45 years and in good health.
  2. Subject has adequate understanding of the procedures of the study and agrees to abide strictly thereby.
  3. Subject is able to communicate well with the investigator, is available to attend all study visits.
  4. Subject agrees to refrain from blood donation to Sanquin or for other purposes throughout the study period.
  5. Subject agrees to refrain from travel to a hookworm endemic area during the course of the trial.
  6. Subject has signed informed consent (note: there are different informed consent forms for group A- and B participants).

Additional inclusion criteria for group B participants:

  1. Agrees to remain infected and to commit to study procedures and rules
  2. Agrees to refrain from blood donation to Sanquin or for other purposes throughout the study period.
  3. Agrees to refrain from travel to a hookworm endemic area during the course of the trial.
  4. Minimum egg output of 1500 epg at the start of the donor phase.
  5. Does not meet any of the criteria for withdrawal outlined in section 8.4.

Exclusion criteria

Exclusion Criteria:

A potential subject who meets any of the following criteria will be excluded from participation in this study:

  1. Any history, or evidence at screening, of clinically significant symptoms, physical signs or abnormal laboratory values suggestive of systemic conditions, such as cardiovascular, pulmonary, renal, hepatic, neurological, dermatological, endocrine, malignant, haematological, infectious, immune-deficient, psychiatric and other disorders, which could compromise the health of the volunteer during the study or interfere with the interpretation of the study results. These include, but are not limited to, any of the following:

    • positive HIV, HBV or HCV screening tests;
    • the use of immune modifying drugs within three months prior to study onset (inhaled and topical corticosteroids and oral anti-histamines exempted) or expected use of such during the study period;
    • having one of the following laboratory abnormalities: ferritine \<10ug/L, transferrine \<2.04g/L or Hb \<6.5 mmol/L for females or \<7.5 mmol/L for males.
    • history of malignancy of any organ system (other than localised basal cell carcinoma of the skin), treated or untreated, within the past 5 years;
    • any history of treatment for severe psychiatric disease by a psychiatrist in the past year;
    • history of drug or alcohol abuse interfering with normal social function in the period of one year prior to study onset;
    • inflammatory bowel syndrome;
    • regular constipation, resulting in bowel movements less than three times per week.
  2. Known hypersensitivity to or contra-indications for use of albendazole, including comedication known to interact with albendazole metabolism (e.g. carbamazepine, phenobarbital, phenytoin, cimetidine, theophylline, dexamethasone).
  3. Known allergy to amphotericin B or gentamicin.
  4. For female subjects: positive urine pregnancy test at screening
  5. Positive faecal qPCR for hookworm at screening, any known history of hookworm infection or treatment for hookworm infection.
  6. Being an employee or student of the study team.
  7. Current or past scars, tattoos, or other disruptions of skin integrity at the intended site of larval application.
  8. increased risk of complications after skin biopsy (e.g. use of anticoagulants, immunosuppressive medication or having tattoo's in the biopsy region).
  9. Any condition or situation that could influence the independent consent of participant (e.g. being a direct colleague or family member of study personnel).
  10. Any other condition or situation that would, in the opinion of the investigator, place the participant at an unacceptable risk of injury or render the participant unable to meet the requirements of the protocol or would compromise the integrity of the data.

Additional exclusion criteria for group B participants:

  1. For female subjects: pregnancy as determined by positive urine hCG measured before stool donation.
  2. Having one of the following laboratory abnormalities: ferritin \<10ug/L, transferrin \<2.04g/L or Hb \<7.0mmol/L for females or \<8.0mmol/L for males.
  3. Positive HIV, HBV or HCV screening tests before donation.
05

Study design

Phase
Not applicable
Primary purpose
Other
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
5 participants (estimated)

Study arms

  • Experimental
    Non-donor group

    Three healthy hookworm-naive volunteers will be infected with 50 Necator americanus L3 larvae in week 0, receive treatment in week 2, followed by another inoculation with 10 Necator americanus L3 larvae localised on one spot after which two biopsies will be taken (one from each arm). After this, they will be treated in week 5. The study ends in week 13.

    Biological: Necator americanus L3 larvae

  • Experimental
    Chronic donor group

    Two healthy hookworm-naive volunteers will be infected with 50 Necator americanus L3 larvae in week 0, receive treatment in week 2, followed by another inoculation with 10 Necator americanus L3 larvae localised on one spot after which two biopsies will be taken (one from each arm). After this, they receive additional inoculations (maximal dose 50 L3 larvae at one time) until egg outputs are \>1500 epg at the start of the donor phase. In the donor phase, volunteers will be asked to donate faeces regularly (\~ 5 -10 times a year). Safety visits are scheduled at month 12 and 24. The study ends after approximately 2 years.

    Biological: Necator americanus L3 larvae

Interventions

  • BiologicalNecator americanus L3 larvae

    Necator americanus L3 larvae

06

What researchers measure

Primary outcomes

  1. Identity of skin effector cells

    Identification of effector cells in the skin by Hyperion Imaging Mass Cytometry after repeated controlled hookworm infections

    Time frame: 3 weeks + 1 day after initial infection (timepoint of taking the biopsies)

  2. Correlation between macroscopic skin response and effector cells

    Association between the macroscopic skin reaction and effector cells present identified by Hyperion Imaging Mass Cytometry

    Time frame: 3 weeks + 1 day after initial infection (timepoint of taking the biopsies)

Secondary outcomes

  1. Measurement of humoral (antibody responses and cytokines) and cellular immunological changes after controlled hookworm infections

    Time frame: 6 weeks from start of the study

  2. Number of hookworm eggs in faeces after infection

    Detection of hookworm eggs by faeces microscopy (Kato-Katz) at week 15-16 in volunteers who volunteered to be chronic donors

    Time frame: 15-16 weeks after start of the study

Other outcomes

  1. Number of adverse events following exposure(s) to hookworm larvae

    Number of adverse events following exposure(s) to hookworm larvae

    Time frame: 12 weeks after last infection timepoint

07

Study locations

1 site
  • Leiden University Medical Center
    Leiden, 2333 ZA, Netherlands
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Start is estimated for Oct 2024; primary completion for Jan 2025, 3 months later.

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

Registered
Jun 24, 2024
First posted
Jun 27, 2024
StartEst.
Oct 1, 2024
Primary completionEst.
Jan 1, 2025
CompletionEst.
Oct 2026
Last update
Jul 12, 2024
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 12, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06478498
Responsible party
Meta Roestenberg (Professor in Infectious Diseases and vaccine development, Leiden University Medical Center) — Principal investigator
First posted
Jun 27, 2024
Start date
Oct 1, 2024 (estimated)
Primary completion
Jan 1, 2025 (estimated)
Completion
Oct 2026 (estimated)
Last update
Jul 12, 2024

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Jul 2024. You cannot join it, but the record below documents what was studied.

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