NCT03014258

Brief Summary

This is a phase I study that will assess the acquisition of immunity to Pf malaria over the course of 5 sequential Controlled Human Malaria Infections (CHMI) over 2-4 years, in 10 healthy adult participants. 10 subjects will initially be challenged with 5 uninfected mosquitoes (mock), followed by 5 challenges with 5 mosquitoes infected with drug sensitive, P. falciparum parasites (strain NF54) 2, 8, 14-20, 20-32, and 32-36 months later. For the final four infective CMHIs six additional immunologic malaria-naïve subjects will be enrolled and challenged as infectivity controls. If dropouts occur within the original 10 person cohort, and two or more CHMI remain, back-up replacement volunteers will be recruited to undergo successive CHMI with the core group. All volunteers (repeat CHMI subjects and infectivity controls) will be evaluated as part of an inpatient stay (or outpatient daily follow-up) to diagnose Pf malaria infection and treat with Coartem(R) (artemether/lumefantrine) or Malarone(R) (Atovaquone/proguanil). Daily observation will occur from Study Days 9-19 or until three-day directly observed therapy for P. falciparum infection is complete and two negative smears separated by a time interval \>12 hours have been documented. A third negative smear \>12 hours after the previous two daily smears will be documented to affirm malaria cure. Infectivity Controls enrolled as part of CHMI #5 will be treated based on concomitant us qPCR results. The repeat CHMI subjects will have additional outpatient visits days 1, 3, 5, and 7 after the challenge to obtain blood samples to monitor the development of immunity. The study is expected to last for 48 months and will include approximately 34 healthy male and female volunteers (10 active study volunteers and 18 naïve controls to confirm Pf infectivity during the 2nd -5th CHMI challenges) ages 18 to 50 years, inclusive, from the greater Baltimore community. The primary objective of this study is to determine whether protective immunity against parasite infection develops following repeat CHMI.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
27

participants targeted

Target at P25-P50 for phase_1

Timeline
Completed

Started Jun 2017

Typical duration for phase_1

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

December 15, 2016

Completed
25 days until next milestone

First Posted

Study publicly available on registry

January 9, 2017

Completed
5 months until next milestone

Study Start

First participant enrolled

June 7, 2017

Completed
2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 19, 2019

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

July 19, 2019

Completed
Last Updated

June 8, 2021

Status Verified

May 27, 2021

Enrollment Period

2.1 years

First QC Date

December 15, 2016

Last Update Submit

June 3, 2021

Conditions

Keywords

BiologyfalciparumImmunityInfectionsMalariaPfPlasmodiumSystems

Outcome Measures

Primary Outcomes (3)

  • Percentage of subjects testing positive for parasites

    As measured using real-time quantitative polymerase chain reaction (PCR)

    Study Day 6 through Study Day 29

  • Percentage of subjects with positive malaria smear

    For infectivity controls enrolled into infective CHMI #5, malaria detection will rely upon ultra-sensitive quantitative polymerase chain reaction (us-qPCR) to ensure safety while conducting this portion of the study as an outpatient

    Study Day 9 through Study Day 29

  • Quantification of parasite infection

    As measured using real-time quantitative polymerase chain reaction (PCR) during the surveillance period after infected CHMI.

    Study Day 6 through Study Day 29

Secondary Outcomes (6)

  • Antibody reactivity against Circumsporozoite protein (CSP)

    Up to Study Day 21

  • Antibody reactivity against Glutamate-rich protein (GLURP)

    Up to Study Day 21

  • Antibody reactivity against Plasmodium Falciparum liver- and erythrocytic-stage antigen

    Up to Study Day 21

  • Antibody reactivity against Plasmodium Falciparum pre-erythrocytic antigen

    Up to Study Day 21

  • Percentage of subjects displaying signs and symptoms attributable to malaria

    Study Day 6 through Study Day 29

  • +1 more secondary outcomes

Study Arms (5)

Control Cohort 1

ACTIVE COMPARATOR

Immunologic malaria-naïve subjects will undergo CHMI #2 with 5 NF54 P. falciparum-infected mosquitoes at months 8-9. n=6.

Biological: NF54 P. falciparum malaria challenge

Control Cohort 2

ACTIVE COMPARATOR

Immunologic malaria-naïve subjects will undergo a CHMI #3 with 5 NF54 P. falciparum-infected mosquitoes at 6-12 months post CHMI #2. n=6.

Biological: NF54 P. falciparum malaria challenge

Control Cohort 3

ACTIVE COMPARATOR

Immunologic malaria-naïve subjects will undergo a CHMI #4 with 5 NF54 P. falciparum-infected mosquitoes at 6-12 months post CHMI #3. n=6.

Biological: NF54 P. falciparum malaria challenge

Control Cohort 4

ACTIVE COMPARATOR

Immunologic malaria-naïve subjects will undergo a CHMI #5 with 5 NF54 P. falciparum-infected mosquitoes at 6-12 months post CHMI #4. n=6.

Biological: NF54 P. falciparum malaria challenge

Repeat CHMI

EXPERIMENTAL

Subjects will initially be challenged with 5 uninfected mosquitoes (mock), followed by 5 challenges (CHMI # 1-5) with 5 NF54 P. falciparum-infected mosquitoes 2, 8, 14-20, and 20-32, and 32-36 months later. n=10.

Biological: NF54 P. falciparum malaria challenge

Interventions

Aseptically-raised A. stephensi female mosquitoes infected with aseptically-raised P. falciparum parasites of the NF54 strain.

Control Cohort 1Control Cohort 2Control Cohort 3Control Cohort 4Repeat CHMI

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Male or non-pregnant/non-lactating female between the ages of 18 and 50 years, inclusive.
  • Able and willing to participate for the duration of the study.
  • Able to provide proof of identity to the satisfaction of the study clinician completing the enrollment process.
  • Able and willing to complete the informed consent process.
  • Willing to refrain from blood donation to blood banks for 3 years following P. falciparum CHMI.
  • Agrees not to travel to a malaria endemic region during the entire course of study participation.
  • Physical examination and laboratory results without clinically significant findings and a body mass index (BMI) = / \< 35.
  • Laboratory Criteria within 56 days prior to enrollment:
  • Hemoglobin = / \>11.2 g/dL for women; = / \> 12.6 g/dL for men.
  • Platelet count within institutional normal range.
  • Alanine aminotransferase (ALT) = / \< upper limit of normal.
  • Serum creatinine = / \< upper limit of normal.
  • Negative for HIV and Hepatitis B/C infection.
  • Laboratory Criterion documented any time prior to enrollment:
  • Negative sickle cell screening test.
  • +3 more criteria

You may not qualify if:

  • Women who are breast-feeding or planning to become pregnant during the time interval needed to complete the study.
  • Receipt of a malaria vaccine in a prior clinical trial.
  • Any history of malaria infection.
  • Evidence of increased cardiovascular disease risk; defined as \> 10% five year risk by the non-laboratory method.
  • Current use of systemic immunosuppressant pharmacotherapy.
  • History of a splenectomy, sickle cell disease or sickle cell trait.
  • Known history of anaphylactic response to mosquito-bites; or known allergy to artemether lumefantrine or atovaquone or proguanil or other component of the product.
  • Participation in any study involving investigational vaccine or drug within 4 weeks prior to enrollment, or expects to receive vaccine or drug during the 2-month post-challenge period.
  • Use or planned use of any drug with anti-malarial activity that would coincide with challenge.
  • Anticipated use of medications known to cause drug reactions with atovaquone-proguanil (Malarone(R)) such as cimetidine, metoclopramide, antacids, and kaolin.
  • Plans to undergo surgery (elective or otherwise) between enrollment and 4 weeks (28 days) after any of the challenges.
  • Received a licensed vaccine within 1 month prior to enrollment in this study or expects to receive one during the 28 day post challenge period.
  • History of psychiatric disorders or behavioral tendencies (including active alcohol or drug abuse) that in the opinion of the investigator would make compliance with the protocol difficult.\* \*Medical and psychiatric illness defined as personality disorders, anxiety disorders, or schizophrenia or social condition, occupational reason or other responsibility that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a volunteer's ability to give informed consent or to comply with the protocol schedule.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Maryland School of Medicine - Center for Vaccine Development - Baltimore

Baltimore, Maryland, 21201-1509, United States

Location

Related Publications (1)

  • Ferrer P, Berry AA, Bucsan AN, Prajapati SK, Krishnan K, Barbeau MC, Rickert DM, Guerrero SM, Usui M, Abebe Y, Patil A, Chakravarty S, Billingsley PF, Pa'ahana-Brown F, Strauss K, Shrestha B, Nomicos E, Deye GA, Sim BKL, Hoffman SL, Williamson KC, Lyke KE. Repeat controlled human Plasmodium falciparum infections delay bloodstream patency and reduce symptoms. Nat Commun. 2024 Jun 18;15(1):5194. doi: 10.1038/s41467-024-49041-2.

MeSH Terms

Conditions

InfectionsMalaria

Condition Hierarchy (Ancestors)

Protozoan InfectionsParasitic DiseasesMosquito-Borne DiseasesVector Borne Diseases

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
OTHER
Intervention Model
PARALLEL
Sponsor Type
NIH
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 15, 2016

First Posted

January 9, 2017

Study Start

June 7, 2017

Primary Completion

July 19, 2019

Study Completion

July 19, 2019

Last Updated

June 8, 2021

Record last verified: 2021-05-27

Locations