A Study to Assess the Experimental Malaria Vaccines R78C and RH5.1 With Matrix-M in Combination With R21/Matrix-M

Phase 2Active Not RecruitingNCT07183371

University of Oxford360 enrolled

Overview

This is a Phase IIb randomised controlled trial of the safety, immunogenicity and efficacy of the malaria vaccine candidates R78C with Matrix-M™, and the combination of RH5.1 and R21 with Matrix-M™, in children aged 5-36 months in Burkina Faso.

There will be three study groups, each comprising of 120 children aged between 5 and 36 months at the time of first vaccination living in a malaria endemic area and will be recruited at one site in Burkina Faso. Participants will be randomised to receive either three doses of the malaria candidate vaccines R78C/Matrix-M and three doses of a commercially available rabies vaccine, three doses of RH5.1+R78C/Matrix-M and three doses of R21/Matrix-M or six doses of commercially available control vaccines. Follow up will be for six months following the last vaccination.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Enrollment

360

Conditions

Malaria,Falciparum

Interventions

R21BIOLOGICAL

A protein particle comprising recombinant HBsAg fused to the central repeat and the C-terminus of the circumsporozoite protein

RH5.1BIOLOGICAL

A soluble protein vaccine against the RH5 antigen

R78CBIOLOGICAL

A soluble RIPR EGF-CyRPA fusion protein vaccine

Eligibility

Sex: ALLMin age: 5 MonthsMax age: 36 MonthsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Only participants who meet all the inclusion criteria will be enrolled into the trial: * Healthy infant aged 5-36 months at the time of first study vaccination * Parent/guardian provides signed/thumb-printed informed consent * Infant and parent/guardian resident in the study area villages and anticipated to be available for vaccination and the duration of follow-up Exclusion Criteria: The participant may not enter the trial if ANY of the following apply: * Clinically significant congenital abnormalities as judged by the PI or other delegated individual. * Clinically significant skin disorder (psoriasis, contact dermatitis etc.), cardiovascular disease, respiratory disease, endocrine disorder, liver disease, renal disease, gastrointestinal disease, neurological illness as judged by the PI or other delegated individual. * Weight-for-age Z score of less than -3 or other clinical signs of malnutrition. * History of allergic reaction, significant IgE-mediated event, or anaphylaxis to immunisation. * History of allergic disease or reactions likely to be exacerbated by any component of the vaccines. * Sickle cell disease. * Clinically significant laboratory abnormality at grade 2 or above as judged by the PI or other delegated individual. * Administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccine candidate. * Receipt of any vaccine in the 14 days preceding enrolment, or planned receipt of any other vaccine within 28 days following each study vaccination. * History of vaccination with another malaria vaccine. * Participation in another research study involving receipt of an investigational product in the 30 days preceding enrolment, or planned use during the study period. * Known maternal HIV infection (no testing will be done by the study team). * 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 (for corticosteroids, this will mean prednisone, or equivalent, ≥ 0.5 mg/kg/day; inhaled and topical steroids are allowed). * 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. The following adverse events associated with vaccine immunisation constitute absolute contraindications to further administration of vaccine. If any of these events occur during the study, the participant must be withdrawn and followed until resolution of the event, as with any adverse event: • Anaphylactic reaction following administration of vaccine. The following adverse events constitute contraindications to administration of vaccine at that point in time; if any one of these adverse events occurs at the time scheduled for vaccination, the participant may be vaccinated at a later date, or withdrawn at the discretion of the Investigator. The participant must be followed until resolution of the event as with any adverse event: * Acute disease at the time of vaccination (acute disease is defined as the presence of a moderate or severe illness with or without fever or symptoms suggestive of possible COVID-19 disease). All vaccines can be administered to persons with a minor illness such as diarrhoea or mild upper respiratory infection without fever, i.e. axillary temperature \< 37.5°C. * Temperature of \>37.5°C (99.5°F) at the time of vaccination.

Locations (1)

Institut de Recherche en Sciences de la Sante - Clinical Research Unit of Nanoro (IRSS-URCN)

Nanoro, Burkina Faso

Outcomes

Primary Outcomes

Efficacy: The primary efficacy outcome is clinical malaria, defined as the presence of axillary temperature ≥37.5°C and P. falciparum parasite density >5000 asexual forms/µL.

To assess the protective efficacy against clinical malaria of R78C with Matrix-M™, and the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™, in children living in a malaria-endemic area, for 6 months after the final vaccination. Primary case definition for clinical malaria: • Presence of axillary temperature ≥37.5°C and/or history of fever within the last 24 hours AND P. falciparum asexual parasitaemia \> 5000 parasites/µL Secondary case definitions for clinical malaria: * Presence of axillary temperature ≥37.5°C and/ or history of fever within the last 24 hours AND EITHER P. falciparum asexual parasitaemia \>0 parasites/µL OR positive RDT * Presence of axillary temperature ≥37.5°C and/ or history of fever within the last 24 hours AND P. falciparum asexual parasitaemia \>20,000 parasites/µL

Time frame: Clinical malaria will be assessed 6 months post final vaccination

Safety: To assess the safety and reactogenicity of R78C, RH5.1 and R21 with Matrix-M™ by assessing solicited adverse events (AEs) in children living in a malaria-endemic area until 6 months after administration of the final dose of vaccine.

The occurrence of solicited local and systemic reactogenicity signs and symptoms will be assessed for 7 days following each vaccination (day of vaccination and 6 subsequent days) Foreseeable adverse reactions following vaccination with RH5.1, R78C or R21 and Matrix-MTM adjuvant are: * Local reactions: pain, erythema, warmth, swelling * Systemic reactions: drowsiness, fever, irritability/fussiness, loss of appetite These AEs will be listed as 'solicited AEs' providing they occur within 7 days of the day of vaccination.

Time frame: Day 0,1-6,28,29-34,98,99-104,126,127-132,154,155-160,182,183-188.

Safety: To assess the safety and reactogenicity of R78C, RH5.1 and R21 with Matrix-M™ by assessing unsolicited adverse events (AEs) in children living in a malaria-endemic area until 6 months after administration of the final dose of vaccine.

The occurrence of unsolicited AEs will be assessed for 7 days following each vaccination (day of vaccination and 6 subsequent days). Unsolicited AEs' are AEs other than the foreseeable adverse reactions occurring within the first 7 days, or any AEs occurring after the first 7 days after vaccination. For every unsolicited AE, an assessment of the relationship of the event to the administration of the vaccine will be undertaken by the PI or the PI-delegated clinician. An intervention-related AE refers to an AE for which there is a possible, probable or definite relationship to administration of a vaccine. An interpretation of the causal relationship of the intervention to the AE in question will be made, based on the type of event; the relationship of the event to the time of vaccine administration; and the known biology of the vaccine therapy

Data from ClinicalTrials.gov

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Secondary Outcomes

Immunogenicity:To assess the humoral immunogenicity of R78C with Matrix-M™, and the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™ in children living in a malaria-endemic area.

Humoral immunogenicity will be assessed from blood samples taken at various timepoints. Immunogenicity will be determined following the quantification of antigen-specific IgG antibody levels (µg/mL readout) over time, as well as by in vitro growth inhibition assays (GIA) against P. falciparum parasites using purified total IgG and a single-cycle pLDH readout assay.

Time frame: Blood samples for immunogenicity will be taken at Day -30 to 0, 0, 42, 56, 182, 196, 238, and 350.

Efficacy: To assess the protective efficacy against clinical malaria of R78C with Matrix-M™, in children living in a malaria-endemic area, for 3 months after the final vaccination

The definition for clinical malaria is as follows: 1. Presence of axillary temperature ≥37.5°C and/ or history of fever within the last 24 hours AND EITHER P. falciparum asexual parasitaemia \>0 parasites/µL OR positive RDT or 2. Presence of axillary temperature ≥37.5°C and/ or history of fever within the last 24 hours AND P. falciparum asexual parasitaemia \>20,000 parasites/µL Efficacy will be determined following the comparison of mean parasite density in each study arm

Time frame: 3 months after the final vaccination

Efficacy: To assess the protective efficacy against clinical malaria of the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™, in children living in a malaria-endemic area, for 3 months after the final vaccination

Time frame: 3 months after the final vaccination

Efficacy: To assess the protective efficacy against asymptomatic P. falciparum infection of R78C with Matrix-M™, and the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™, in children living in a malaria-endemic area.

This will be measured by looking at the following: * Proportion of participants in each study arm that show presence of parasite density \>5000 asexual forms/µL as measured by quantitative reverse-transcriptase PCR (qRT-PCR) from 14 days to 2 and 6 months after administration of the final study vaccination PLUS presence of axillary temperature \<37.5°C and absence of history of fever within the last 24 hours * Proportion of participants in each study arm that show presence of parasite density \>0 asexual forms/µL as measured by qRT-PCR from 14 days to 2 and 6 months after administration of the final study vaccination PLUS presence of axillary temperature \<37.5°C and absence of history of fever within the last 24 hours * Parasite density in those with \>0 asexual forms/µL as measured by qRT-PCR from 14 days to 2 and 6 after administration of the final study vaccination PLUS presence of axillary temperature \<37.5°C and absence of history of fever within the last 24 hours

Time frame: 2 and 6 months after administration of the final dose of vaccine

Efficacy: To assess the protective efficacy against gametocytaemia of R78C with Matrix-M™, and the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™, in children living in a malaria-endemic area

Protective efficacy against gametocytaemia will be assessed by measuring the proportion of participants in each study arm that show the presence of gametocytes \>0 gametocytes/μL as measured by qRT-PCR from 14 days to 2 and 6 months after administration of the final study vaccination

Time frame: 2 and 6 months after administration of the final dose of vaccine

Efficacy: To assess the protective efficacy of R78C with Matrix-M™, and the combination of RH5.1 with Matrix-M™ and R21 with Matrix-M™, against prevalent moderate or severe anaemia at 6 months after administration of the final dose of vaccine

Prevalent severe anaemia is defined as a documented haemoglobin (Hb) level \<5.0 g/dL. Prevalent moderate anaemia is defined as a documented Hb level \<8.0 g/dL.

Time frame: 6 months after administration of the final dose of vaccine