Experimental Human Malaria Infection After Immunization With Plasmodium Falciparum Sporozoites Under Chloroquine Prophylaxis

Plasmodium Falciparum Malaria Clinical Trial

— EHMI9  

Official title:

Experimental Human Malaria Infection After Immunization With Plasmodium Falciparum Sporozoites Under Chloroquine Prophylaxis

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01236612
• Other study ID #: EHMI9
• Status: Completed
• Phase: N/A
• First received: November 4, 2010
• Last updated: January 20, 2014
• Start date: April 2011
• Est. completion date: June 2012

Study information

• Verified date: January 2014
• Source: Radboud University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)
• Study type: Interventional

Clinical Trial Summary

Malaria is one of the major infectious diseases in the world with a tremendous impact on the quality of life significantly contributing to the ongoing poverty in endemic countries. It causes almost one million deaths per year, the majority of which are children under the age of five. The malaria parasite enters the human body through the skin, by the bite of an infected mosquito. Subsequently, it invades the liver and develops and multiplies inside the hepatocytes. After a week, the hepatocytes burst open and the parasites are released in the blood stream, causing the clinical phase of the disease.

As a unique opportunity to study malaria immunology and efficacy of immunisation strategies, a protocol has been developed in the past to conduct experimental human malaria infections (EHMIs). EHMIs generally involve small groups of malaria-naïve volunteers infected via the bites of P. falciparum infected laboratory-reared Anopheline mosquitoes. Although potentially serious or even lethal, Plasmodium falciparum (P.falciparum) malaria can be radically cured at the earliest stages of blood infection where risks of complications are virtually absent.

The investigators have shown previously, that healthy human volunteers can be protected from a malaria mosquito challenge by immunization with mosquito-bites under chloroquine prophylaxis (CPS immunization). However, it is unknown whether this protection is based on immunity directed towards the liver- or the blood stage of the disease. For future development of vaccines and understanding of protective immunity to malaria, it is important to investigate at which level protective immunity is generated by CPS immunization. Therefore, we aim to investigate whether CPS immunization confers protection to a blood-stage challenge.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: June 2012
• Est. primary completion date: June 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

1. Age > 18 and < 35 years healthy volunteers (males or females)

2. Good health based on history and clinical examination

3. Negative pregnancy test

4. Use of adequate contraception for females

5. All volunteers must sign the informed consent form demonstrating their understanding of the meaning and procedures of the study

6. Volunteer agrees to inform the general practitioner and agrees to sign a request to release medical information concerning contra-indications for participation in the study

7. Willingness to undergo a Pf mosquito or blood stage challenge

8. For volunteers not living in Nijmegen: agreement to stay in a hotel room close to the trial center during a part of the study (for groups 1 and 3 from challenge day till 3 days after treatment, for groups 2 and 4 from 5 days after challenge till 3 days after treatment)

9. Reachable (24/7) by mobile phone during the whole study period

10. Living with a third party that could contact the clinicians in case of alteration of consciousness or agreement to stay in a hotel room close to the trial center during a part of the study (for groups 1 and 3 from challenge day till 3 days after treatment, for groups 2 and 4 from 5 days after challenge till 3 days after treatment)

11. Available to attend all study visits

12. Agreement to refrain from blood donation to Sanquin or for other purposes, during the study period until 393

13. Willingness to undergo HIV, hepatitis B and hepatitis C tests

14. Negative urine toxicology screening test at screening visit and day before challenge

15. Willingness to take a prophylactic regime of chloroquine and curative regimen of Malarone®

Exclusion Criteria:

1. History of malaria

2. Plans to travel to malaria endemic areas during the study period

3. Plans to travel outside of the Netherlands during the challenge period

4. Previous participation in any malaria vaccine study and/or positive serology for Pf

5. Symptoms, physical signs and laboratory values suggestive of systemic disorders including renal, hepatic, cardiovascular, pulmonary, skin, immunodeficiency, psychiatric, and other conditions which could interfere with the interpretation of the study results or compromise the health of the volunteers

6. History of diabetes mellitus or cancer (except basal cell carcinoma of the skin)

7. History of arrhythmias or prolonged QT-interval

8. Positive family history in 1st and 2nd degree relatives for cardiac disease < 50 years old

9. An estimated, ten year risk of fatal cardiovascular disease of =5%, as estimated by the Systematic Coronary Risk Evaluation (SCORE) system

10. Clinically significant abnormalities in electrocardiogram (ECG) at screening

11. Body Mass Index (BMI) below 18 or above 30 kg/m2

12. Any clinically significant deviation from the normal range in biochemistry or hematology blood tests or in urine analysis

13. Positive HIV, HBV or HCV tests

14. Participation in any other clinical study within 30 days prior to the onset of the study

15. Enrollment in any other clinical study during the study period

16. Pregnant or lactating women

17. Volunteers unable to give written informed consent

18. Volunteers unable to be closely followed for social, geographic or psychological reasons

19. Previous history of drug or alcohol abuse interfering with normal social function during a period of one year prior to enrolment in the study

20. A history of psychiatric disease

21. Known hypersensitivity to anti-malaria drugs

22. The use of chronic immunosuppressive drugs, antibiotics, or other immune modifying drugs within three months of study onset (inhaled and topical corticosteroids are allowed) and during the study period

23. Contra-indications to Malarone® or chloroquine including treatment taken by the volunteer that interferes with Malarone® or chloroquine

24. Any confirmed or suspected immunosuppressive or immunodeficient condition, including asplenia

25. Co-workers of the departments of Medical Microbiology or Internal Medicine of the RUNMC

26. A history of sickle cell anemia, sickle cell trait, thalassemia, thalassemia trait or G6PD deficiency

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Malaria
• Malaria, Falciparum
• Plasmodium Falciparum Malaria

Intervention

Drug:
• Chloroquine prophylaxis
The chloroquine dose used will be 300mg for the first two days, followed by 300mg per week, for 13 weeks.

Biological:
• Immunization
Groups 1 and 2 will be immunized with 3 times 15 bites of Pf infected mosquitoes under chloroquine prophylaxis.
• Plasmodium falciparum Bloodstage challenge
Groups 1 and 3 will be challenged by intravenous administration of Plasmodium falciparum infected erythrocytes.
• Plasmodium falciparum mosquito challenge
Groups 2 and 4 will be challenged by the bites of 5 Plasmodium falciparum infected mosquitoes.

Drug:
• Malarone treatment
When thick smear positive, of ar day 21 after challenge, all volunteers will be treated with malarone.

Locations

Country	Name	City	State
Netherlands	Radboud University Nijmegen Medical Centre	Nijmegen

Sponsors (1)

Lead Sponsor	Collaborator
Radboud University

Country where clinical trial is conducted

Netherlands, 

References & Publications (2)

Bijker EM, Bastiaens GJ, Teirlinck AC, van Gemert GJ, Graumans W, van de Vegte-Bolmer M, Siebelink-Stoter R, Arens T, Teelen K, Nahrendorf W, Remarque EJ, Roeffen W, Jansens A, Zimmerman D, Vos M, van Schaijk BC, Wiersma J, van der Ven AJ, de Mast Q, van — View Citation

Roestenberg M, McCall M, Hopman J, Wiersma J, Luty AJ, van Gemert GJ, van de Vegte-Bolmer M, van Schaijk B, Teelen K, Arens T, Spaarman L, de Mast Q, Roeffen W, Snounou G, Rénia L, van der Ven A, Hermsen CC, Sauerwein R. Protection against a malaria challenge by sporozoite inoculation. N Engl J Med. 2009 Jul 30;361(5):468-77. doi: 10.1056/NEJMoa0805832. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Duration of prepatent period as measured by microscopy		21 days after challenge	No
Primary	Parasitemia and kinetics of parasitemia as measured by PCR		21 days after challenge	No
Primary	Frequency of signs or symptoms in study groups		21 days after challenge	No
Secondary	Antibody production in groups 1, 2, 3 and 4		393 days	No
Secondary	Cellular immune response in groups 1, 2, 3 and 4		393 days	No
Secondary	Cytokine profile in groups 1, 2, 3 and 4		393 days	No