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Re-exposure of Human Volunteers to a Heterologous Strain of P. Falciparum Sporozoites (TIP4)

12. februar 2013 oppdatert av: Radboud University Medical Center

Re-exposure of Previously Immunized and Challenged Human Volunteers to a Heterologous Strain of P. Falciparum Sporozoites

In a previous study (NL33904.091.10) the investigators challenged 24 volunteers after Chloroquine Prophylaxis Sporozoites (CPS) immunization with 45, 30 or 15 infected mosquito-bites respectively. The availability of this immunized cohort opens the unique opportunity to determine protection to a heterologous challenge for both of the protected and unprotected volunteers as the previous challenge infection might have served as immunological boost to the unprotected volunteers.

In the current observational, proof of principle study, the investigators aim to investigate the protection on an individual basis of these previously immunized and challenged volunteers against a heterologous P. falciparum challenge.

Studieoversikt

Studietype

Intervensjonell

Registrering (Faktiske)

21

Fase

  • Ikke aktuelt

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiesteder

      • Leiden, Nederland, 2333ZA
        • Leiden University Medical Centre

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

18 år til 35 år (Voksen)

Tar imot friske frivillige

Ja

Kjønn som er kvalifisert for studier

Alle

Beskrivelse

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. Signing of the informed consent form, thereby demonstrating understanding of the meaning and procedures of the study
  6. Agreement to inform the general practitioner and to sign a request to release medical information concerning contra-indications for participation in the study
  7. Willingness to undergo a Pf controlled challenge through mosquito bites
  8. Agreement to stay in a hotel room close to the trial centre during a part of the study (Day 5 after challenge till treatment is finished)
  9. Reachable (24/7) by mobile phone during the whole study period
  10. Available to attend all study visit
  11. Agreement to refrain from blood donation to Sanquin or for other purposes, during the whole study period
  12. Willingness to undergo HIV, hepatitis B and hepatitis C tests
  13. Negative urine toxicology screening test at screening visit and the day before challenge
  14. Willingness to take a curative regimen of Malarone®

Exclusion Criteria:

  1. History of malaria (other than participation in ZonMw1 study) or residence in malaria endemic areas within the past six months
  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 (except ZonMw1 volunteers)
  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 events < 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. For women: being pregnant or lactating
  17. Volunteers unable to give written informed consent
  18. Volunteers unable to be closely followed for social, geographic or psychological reasons
  19. History of drug or alcohol abuse interfering with normal social function
  20. A history of treatment for psychiatric disease
  21. A history of convulsions
  22. Contra-indications to Malarone®, including hypersensitivity or treatment taken by the volunteer that interferes with Malarone®
  23. The use of chronic immunosuppressive drugs, antibiotics, or other immune modifying drugs within three months of study onset (inhaled and topical corticosteroids and oral anti-histaminic are allowed) and during the study period
  24. Any confirmed or suspected immunosuppressive or immunodeficient condition, including (functional) asplenia
  25. Co-workers or trainees of the departments Infectious Diseases, Medical Microbiology or Parasitology of the Leiden University Medical Centre (LUMC) or Medical Microbiology, Parasitology, Radboud University Nijmegen (RUNMC)
  26. A history of sickle cell anaemia, sickle cell trait, thalassaemia (or trait), G6PD deficiency

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Primært formål: Grunnvitenskap
  • Tildeling: Ikke-randomisert
  • Intervensjonsmodell: Parallell tildeling
  • Masking: Ingen (Open Label)

Våpen og intervensjoner

Deltakergruppe / Arm
Intervensjon / Behandling
Eksperimentell: Heterologous challenge

Biological: Heterologous challenge with 5 infected mosquito bites (NF135) after previous CPS immunization and challenge.

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

Other Name: atovaquone/proguanil

challenge by the bites of 5 Plasmodium falciparum infected mosquitoes.
Three days: 4 tablets 250/100mg per day
Andre navn:
  • atovaquon/proguanil
Aktiv komparator: Challenge control

Biological: Plasmodium falciparum mosquito challenge by the bites of 5 Plasmodium falciparum infected mosquitoes (NF135).

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

Other Name: atovaquone/proguanil

challenge by the bites of 5 Plasmodium falciparum infected mosquitoes.
Three days: 4 tablets 250/100mg per day
Andre navn:
  • atovaquon/proguanil

Hva måler studien?

Primære resultatmål

Resultatmål
Tidsramme
Duration of prepatent period after challenge infection as measured by microscopy
Tidsramme: 21 days after challenge
21 days after challenge

Sekundære resultatmål

Resultatmål
Tidsramme
Hyppighet av tegn eller symptomer i studiegrupper
Tidsramme: 21 dager etter utfordring
21 dager etter utfordring
• Parasitemia and kinetics of parasitemia as measured by PCR
Tidsramme: 21 days after challenge
21 days after challenge
• Immune responses between study groups
Tidsramme: 21 days after challenge
21 days after challenge

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Etterforskere

  • Studieleder: RW Sauerwein, PhD, Radboud University Medical Center

Publikasjoner og nyttige lenker

Den som er ansvarlig for å legge inn informasjon om studien leverer frivillig disse publikasjonene. Disse kan handle om alt relatert til studiet.

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart

1. juli 2012

Primær fullføring (Faktiske)

1. januar 2013

Studiet fullført (Faktiske)

1. januar 2013

Datoer for studieregistrering

Først innsendt

23. juli 2012

Først innsendt som oppfylte QC-kriteriene

6. august 2012

Først lagt ut (Anslag)

9. august 2012

Oppdateringer av studieposter

Sist oppdatering lagt ut (Anslag)

13. februar 2013

Siste oppdatering sendt inn som oppfylte QC-kriteriene

12. februar 2013

Sist bekreftet

1. juli 2012

Mer informasjon

Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .

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