A Clinical Study to Develop an Uninfected Sand Fly Biting Protocol (FLYBITE)

October 28, 2022 updated by: Paul Kaye, University of York

A Clinical Study to Develop a Sand Fly Biting Protocol Using Pathogen-free Blood-fed Sand Flies

The disease leishmaniasis mainly occurs in hot and tropical countries, affects millions of people and causes around 20,000 deaths across the world every year. Leishmaniasis is caused by the Leishmania parasite and is transmitted by sand flies. The parasite is tiny and not visible to the naked eye, whereas the particular sand fly is visible but small and inconspicuous. There are different types of leishmaniasis around the world and some can be very serious. They affect the skin (cutaneous leishmaniasis) or the internal organs of the body (visceral leishmaniasis). Some of the milder forms will produce skin problems which will be localised, whilst other forms of leishmaniasis will cause widespread skin changes. The skin lesions of cutaneous leishmaniasis can be disfiguring if left untreated.

There are some treatments for leishmaniasis available but many of them are not easy to use or don't work well. Therefore new treatments and vaccines are needed that prevent or work against leishmaniasis.

A solution being adopted for other diseases, which the investigators now wish to adopt for leishmaniasis is to develop a 'Controlled human infection model' (CHIM). These models involve deliberate exposure of individuals to an infection, in order to better understand how the disease works and to test potential vaccines and treatments. They have contributed vital scientific knowledge that has led to advances in the development of drugs and vaccines.

This is an initial study using uninfected (disease-free) sand flies, taking place at the University of York. The information from this study will help us to develop a model in the future using infected sand flies so that the investigators can assess any future vaccines against Leishmaniasis. The investigators will also hold a focus group after the sand fly biting study to explore the experiences of individuals taking part in this study.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a healthy-volunteer clinical study to develop a sand fly biting protocol. 12 participants will be recruited for the study. It is an open-label randomized clinical study with 2 arms (for 2 different species of sand fly: Phlebotomus papatasi and Phlebotomus duboscqi). Participants will be randomized to each arm with 6 participants in each arm. This study will take place at the Translational Research Facility (Q Block), Hull York Medical School & Department of Biology, University of York, York.

The participants will be followed up to 21 days post-sand fly bite. There will then be a focus group once all participants have completed their follow-up.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
12

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • North Yorkshire
      • York, North Yorkshire, United Kingdom
        • Translational Research Facility, Department of Biology, University of York

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy adults aged 18 to 65 years on the day of screening
  • Willing and able to give written informed consent
  • Willing to undergo an Hepatitis B, Hepatitis C & HIV test
  • Willing to undergo a pregnancy test during screening and follow-up visits and must not be breastfeeding (female volunteers)
  • Willing to refrain from blood donation during the study
  • Using a reliable and effective form of contraception (female volunteers)
  • Judged, in the opinion of a medically qualified Clinical Investigator, to be able and likely to comply with all study requirements as set out in the protocol
  • Without any other significant health problems as determined by medical history, physical examination, results of screening tests and the clinical judgment of a medically qualified Clinical Investigator
  • Available for the duration of the study
  • Willing to refrain from travel to regions where Leishmania-transmitting sand flies are present, from recruitment until the last study visit.
  • Willing to consent to a report from the volunteer's GP (General Practitioner) confirming medical eligibility, to be provided before study entry

Exclusion Criteria:

The volunteer may not enter the study if any of the following apply:

  • Receipt of a live attenuated vaccine within 30 days or other vaccine within 14 days of screening
  • Administration of immunoglobulins and/or any blood products within the three months preceding the planned study.
  • History of allergic disease/atopy or reactions or a history of severe or multiple allergies to drugs or pharmaceutical agents
  • Any significant chronic skin condition as judged by the medical team
  • Any history of Leishmaniasis
  • Any history of travel within the last 30 days to regions where Leishmania major-transmitting sand flies are endemic*.
  • Any past history of more than 30 contiguous days stay in regions where Leishmania major-transmitting sand flies are endemic*.
  • Any history of severe local or general reaction to insect bites, defined as
  • Local: extensive, indurated redness and swelling involving most of the antero-lateral thigh or the major circumference of the arm, not resolving within 72 hours
  • General: fever ≥ 39.5°C within 48 hours, anaphylaxis, bronchospasm, laryngeal oedema, collapse, convulsions or encephalopathy within 48 hours
  • Any history of anaphylaxis Females - pregnancy, less than 12 weeks postpartum, lactating or willingness/intention to become pregnant during the study and for 3 months following the study.
  • Any clinically significant abnormal finding on screening biochemistry or haematology blood tests or urinalysis
  • Total IgE levels >81 Kilo-units/L Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months
  • Tuberculosis, leprosy, or malnutrition
  • Any chronic illness requiring hospital specialist input
  • Any significant psychiatric conditions
  • Any other significant disease, disorder or finding, which, in the opinion of a medically qualified Clinical Investigator, may either put the volunteer at risk because of participation in the study, or may influence the result of the study, or the volunteer's ability to participate in the study
  • Unlikely to comply with the study protocol
  • Involved in current or recent research within the past 3 months (as judged by study investigators) *This refers to regions where Leishmania major-transmitting sand flies are endemic including (but not limited to) the Middle East, Sub-Saharan Africa, and Asia.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Phlebotomus papatasi sand fly bite
Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the sand fly species Phlebotomus papatasi fed on blood twice in the laboratory prior to human exposure.
Other: Sand fly bite
Comparison between sand fly bites from two different species (Phlebotomus papatasi and Phlebotomus duboscqi)
Active Comparator: Phlebotomus duboscqi sand fly bite
Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the sand fly species Phlebotomus duboscqi fed on blood twice in the laboratory prior to human exposure.
Other: Sand fly bite
Comparison between sand fly bites from two different species (Phlebotomus papatasi and Phlebotomus duboscqi)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Percentage of participants who successfully undergo sand fly bite during a 30 minute exposure determined by visual dermatoscopy
Time Frame: 21 days

Development of a sand fly biting protocol using pathogen-free sand flies which is effective and safe for volunteers:

Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the two sand fly species Phlebotomus papatasi and Phlebotomus duboscqi fed on blood twice in the laboratory prior to human exposure.
21 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Percentage of participants with visual changes following sand fly bite using photography.
Time Frame: 21 days
The investigators will use photography to identify and record skin changes following sand fly bite by use of photography.
21 days
Percentage of participants with visual changes following sand fly bite using dermatoscopy.
Time Frame: 21 days
The investigators will use dermatoscopy to identify and record skin changes following sand fly bite.
21 days
Percentage of participants with demonstrable serological evidence of sand fly bite. To determine human immunological response to sand fly bite using serology and cellular response measurement.
Time Frame: 21 days
The investigators will measure serology including Leishmania and sand fly salivary gland antibodies following sand fly bite.
21 days
Percentage of participants with demonstrable cellular response evidence of sand fly bite.
Time Frame: 21 days
The investigators will measure cellular response following sand fly bite
21 days
Percentage of participants with demonstrable evidence of change in IgE (immunoglobulin E) following sand fly bite.
Time Frame: 21 days
The investigators will measure IgE at baseline and following sand fly bite
21 days
Percentage of participants with significant change in C-reactive protein following sand fly bite.
Time Frame: 21 days
C-Reactive protein will be measured at baseline and following sand fly bite/
21 days
Determine size of lesion following sand fly bite over time
Time Frame: 21 days
Rulers will be used to determine the changing size of any lesion
21 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of York

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Medical Research Council

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 3, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 23, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 10, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 23, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 24, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 27, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 31, 2022

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 28, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RE19_030_266151

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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