A Study to Determine if New Types of Malaria Vaccines Are Safe, Effective and Lead to Immunity in Kenyan Adults

February 17, 2025 updated by: University of Oxford

Safety, Immunogenicity, and Efficacy of R21/Matrix-M and ChAd63/MVA-ME-TRAP in the Context of Controlled Human Malaria Infection: A Phase IIb Trial in Kenyan Adults

This is a phase IIb clinical trial in malaria-exposed individuals to assess the immunogenicity, safety and efficacy of the two vaccines in the context of controlled human malaria infection, P. falciparum sporozoite challenge (PfSPZ Challenge).

Study Overview

Status

Status

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

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

A total of 64 participants will be enrolled for challenge and divided into four groups as follows:

  • 20 participants to receive R21/Matrix M (R21/MM) with intradermal PfSPZ Challenge;
  • 20 participants to receive viral-vectored ME-TRAP with intradermal PfSPZ Challenge;
  • 10 participants to receive R21/MM with direct venous inoculation PfSPZ Challenge; and
  • 14 participants comprising of the control group with intradermal PfSPZ Challenge.

Blood tests and clinical assessments will be conducted to screen out participants with health conditions that may impact participation in the study.

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.
80

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.
  • Phase 2

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

  • Kenya
      • Kilifi, Kenya, PO Box 230, 80108
        • KEMRI/Wellcome Trust Programme, Centre for Geographic Medicine Research - Coast

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 41 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy adults aged 18 to 45 years
  • Able and willing (in the Investigator's opinion) to comply with all study requirements
  • Non-pregnant, non-lactating adult female or adult male
  • Agreement to refrain from blood donation during the study
  • Use of effective method of contraception for the duration of study for female participants. For those with no contraception, they will be referred for contraception at the relevant health facility. For female participants, we will ask them to attend with their family planning records for verification. Effective contraception is defined as a contraceptive method with failure rate of less than 1% per year when used consistently and correctly, in accordance with the product label. Examples of these include: combined oral contraceptives; injectable progestogen; implants of etenogestrel or levonorgestrel; intrauterine device or intrauterine system; male condom combined with a vaginal spermicide (foam, gel, film, cream or suppository); and male condom combined with a female diaphragm, either with or without a vaginal spermicide (foam, gel, film, cream, or suppository)
  • Provide written informed consent
  • Plan to remain resident in the study area for 1 year following first dose of vaccination

Exclusion Criteria:

  • Clinically significant congenital abnormalities as judged by the study clinicians
  • 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 (inhaled and topical steroids are allowed).
  • Sickle cell disease
  • Any history of anaphylaxis in relation to vaccination
  • Clinically significant laboratory abnormality as judged by the study clinician
  • Blood transfusion within one month of enrolment
  • Haemoglobin less than 11.3 g/dl for men and less than 10g/dl for in women, where judged to be clinically significant in the opinion of the investigator.
  • Administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccine candidate
  • Participation in another research study involving receipt of an investigational product in the 30 days preceding enrolment, or planned use during the study period
  • Seropositive for hepatitis B surface antigen (HBsAg) or hepatitis C (HCV IgG)
  • Use of systemic antibiotics with known antimalarial activity within 30 days of administration of PfSPZ Challenge (e.g. trimethoprim-sulfamethoxazole, doxycycline, tetracycline, clindamycin, erythromycin, fluoroquinolones and azithromycin)
  • Women only; pregnancy, or an intention to become pregnant a day before challenge i.e. at C-1
  • Any significant disease, disorder or situation which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial
  • Confirmed parasite positive by PCR a day before challenge i.e. at C-1.

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: Treatment
  • 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.
Experimental: Group 1
Group 1 adults (n=24) will be receiving, 4 weeks apart, three doses of 10µg R21 /50µg Matrix M vaccine, and a CHMI intradermally (ID) by inoculation of 22,500 PfSPZ Challenge.
Biological: R21/Matrix-M
R21: Protein particle malaria vaccine candidate in Matrix-M: Saponin based vaccine adjuvant.
Biological: intradermal injection (ID) or direct venous injection (DVI) of PfSPZ Challenge
PfSPZ Challenge: cryopreserved Plasmodium falciparum sporozoites.
Experimental: Group 2
Group 2 adults (n=24) will be receiving 5x10^10 vp ChAd63 ME-TRAP and 2x10^8 pfu MVA ME-TRAP vaccines, 8 weeks apart, and then a CHMI intradermally (ID) by inoculation of 22,500 PfSPZ Challenge, 4 weeks later.
Biological: intradermal injection (ID) or direct venous injection (DVI) of PfSPZ Challenge
PfSPZ Challenge: cryopreserved Plasmodium falciparum sporozoites.
Biological: ChAd63/MVA ME-TRAP
ChAd63, chimpanzee adenovirus serotype 63; ME-TRAP, multiple epitope string fused to the thrombospondin-related adhesion protein; MVA, modified vaccinia Ankara.
Experimental: Group 3
Group 3 adults (n=14) will be receiving, 4 weeks apart, three doses of 10µg R21 /50µg Matrix M vaccine, and a CHMI intravenously (DVI) by inoculation of 3,200 PfSPZ Challenge.
Biological: R21/Matrix-M
R21: Protein particle malaria vaccine candidate in Matrix-M: Saponin based vaccine adjuvant.
Biological: intradermal injection (ID) or direct venous injection (DVI) of PfSPZ Challenge
PfSPZ Challenge: cryopreserved Plasmodium falciparum sporozoites.
Experimental: Group 4
Group 4 adults (n=18) will be the control group receiving no vaccine, only a CHMI intradermally (ID) by inoculation of 22,500 PfSPZ Challenge.
Biological: intradermal injection (ID) or direct venous injection (DVI) of PfSPZ Challenge
PfSPZ Challenge: cryopreserved Plasmodium falciparum sporozoites.

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
Occurrence of solicited local and systemic reactogenicity signs and symptoms, and unsolicited adverse events
Time Frame: Solicited AEs are collected for 7 days post vaccination and unsolicited AEs for 28 days post vaccination
Assessing the safety and reactogenicity of adjuvanted R21/MM and heterologous prime- boost regime of ChAd63-MVA ME-TRAP in healthy adult volunteers
Solicited AEs are collected for 7 days post vaccination and unsolicited AEs for 28 days post vaccination
Occurrence of P. falciparum parasitemia assessed by PCR, and parasite density dynamics assessed by PCR, against malaria sporozoite challenge
Time Frame: up to 3 months after malaria sporozoite challenge
To assess the safety of intradermal sporozoite infection dose in semi-immune healthy adult volunteers
up to 3 months after malaria sporozoite challenge
Occurrence of P. falciparum parasitemia, assessed by qPCR
Time Frame: from vaccination day up to 90 days after malaria sporozoite challenge
To assess the efficacy of adjuvanted R21 and heterologous prime- boost regime of ChAd63-MVA ME-TRAP against malaria sporozoite challenge, in healthy adult volunteers
from vaccination day up to 90 days after malaria sporozoite challenge

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
To measure cellular immunogenicity assessed by ELISPOT
Time Frame: from vaccination day up to 90 days after malaria sporozoite challenge
Assessing cellular immunogenicity by ELISPOT to enumerate IFN-ƴ producing T cells
from vaccination day up to 90 days after malaria sporozoite challenge
To measure humoral immunogenicity assessed by ELISA
Time Frame: from vaccination day up to 90 days after malaria sporozoite challenge
Assessing humoral immunogenicity by ELISA to quantify antibodies to the vaccine components CS, NANP, TRAP and HBsAb.
from vaccination day up to 90 days after malaria sporozoite challenge
Parasite density dynamics assessed by qPCR
Time Frame: up to 3 months after malaria sporozoite challenge
To assess any differences in efficacy estimates with ID versus DVI challenge in individuals receiving R21/MM
up to 3 months after malaria sporozoite challenge

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 Oxford

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.
European and Developing Countries Clinical Trials Partnership (EDCTP)
Kenya Medical Research Institute

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.
August 31, 2022

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.
February 26, 2023

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.
February 26, 2023

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 7, 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.
May 10, 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.
May 13, 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.
March 25, 2025

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.
February 17, 2025

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.
September 1, 2022

More Information

Terms related to this study

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.
  • VAC074

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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