A Challenge Study to Assess the Blood-stage Efficacy of Full-length SUM-101 Malaria Vaccine Candidate (CHMI-SUM-101)

November 20, 2025 updated by: European Vaccine Initiative

A Randomised Phase Ib Trial to Assess the Blood-stage Efficacy of SUM-101 Malaria Vaccine in Adults Residing in Malaria-endemic Settings, After Controlled Human Malaria Infection Using 3D7 P. Falciparum Blood-stage Malaria Infection

The goal of the study is to test the efficacy using a homologous CHMI of this vaccine candidate early in the development path in a population living in malaria-endemic areas.

In the previous Phase Ia and Ib trials, no efficacy endpoints were defined, and therefore there is currently no data on the SUM-101 vaccine efficacy. The proposed clinical trial will enrol malaria pre-exposed healthy adults and will be the second trial where the IMP will be administered to healthy adult participants in Tanzania with some pre-existing immunity against malaria.

The vaccination part of this study will be performed in a randomised, double-blinded, controlled design to evaluate the safety, reactogenicity and immunogenicity of the candidate malaria vaccine SUM-101 (MSP1 with GLA-SE as adjuvant). Given that SUM-101 is a malaria vaccine with an important blood-stage component, we propose to use CHMI with the 3D7 P. falciparum strain-infected red blood cells to establish initial vaccine efficacy data after the third vaccination in a malaria-exposed population.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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

Full-length MSP1/GLA-SE (SUM-101) malaria vaccine (formerly SumayaVac-1) has been developed by Sumaya Biotech, a spin-off from Heidelberg University, Germany. SUM-101 is a vaccine based on the 3D7 strain (D-form) of full-length merozoite surface protein 1 (full-length MSP1). The full-length MSP1 is expressed as a recombinant heterodimeric protein in E. coli and lyophilised at 150 μg/vial. The lyophilised MSP1 protein is stored at 2 - 8°C. The adjuvant, GLA-SE, was developed by Access to Advanced Health Institute (AAHI), a Washington non-profit corporation with offices at 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA. It is a stable oil-in-water emulsion containing a synthetic analogue of bacterial glucopyranosyl lipid A and functions as a toll-like receptor 4 agonist. A vial of the adjuvant contains 20μg of GLA-SE in a 400μl emulsion. GLA-SE adjuvant and emulsion formulations should be stored at 2 - 8°C.

The vaccine (SUM-101) is prepared before administration by reconstituting the lyophilised protein in saline (aqueous 0.9% NaCl) and then combining it with the GLA-SE adjuvant. The formulated vaccine is stable at room temperature for up to 60 minutes and administered intramuscularly.

A Phase I first-in-human, double-blinded, randomised trial (PMC6994672) was conducted to assess the safety and immunogenicity of SUM-101 in healthy malaria-naïve adult volunteers in Heidelberg, Germany. The trial demonstrated that SUM-101 is safe, with no serious adverse events (SAE) reported. Vaccination with SUM-101 induced MSP1 specific IgG and IgM antibodies that activated Fc-mediated effector mechanisms and were equally reactive against the vaccine variant (MSP1D/3D7) and a heterologous variant of MSP1 (MSP1F/FCB1). In addition, a Phase Ib trial was conducted in Bagamoyo, Tanzania (NCT05644067, data not yet published) where 20 healthy Tanzanian adults were vaccinated with SUM-101. Preliminary results indicate that SUM-101 is safe and well-tolerated in healthy African adults living in malaria-endemic areas, with ongoing assessments of antibody responses.

Concurrently with this trial, a Phase Ib, randomised, controlled age de-escalation, dose-finding study to evaluate the safety, reactogenicity and immunogenicity of full-length MSP1/GLA-SE (SUM-101) malaria vaccine in healthy young children, and infants (NCT06618885) will be conducted in Burkina Faso. The protocol has been submitted for ethical and regulatory approval in Burkina Faso.

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 (Estimated)

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.
24

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 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Written informed consent obtained before any study procedure.
  • Literate participants aged ≥18 - ≤45 years of African origin.
  • Female and male participants willing to practice effective contraception from 4 weeks before 1st vaccination (female participants only) and up to 12 weeks after the last vaccination or CHMI (female and male participants)
  • Female participants must be willing to undergo multiple serum pregnancy tests.
  • Available to participate in follow-up for the duration of the study, including the CHMI in-patient confinement period.
  • Contactable by phone during the whole study period.
  • At least two years of residence in the Bagamoyo district or nearby districts in the Coastal and Dar-es-Salaam regions and planning to reside there for at least 9 more months.
  • Agreement to provide personal contact information and contact information of another household member or close friend.
  • Confirmation of understanding of design, procedures, risks and benefits of the study by scoring 10 out of 10 in a structured ten questions with a maximum of two attempts.
  • General good health based on assessment of medical history and clinical examination.
  • The volunteer agrees to refrain from blood donation for 12 months following CHMI.
  • Volunteer agrees to refrain from intensive physical exercise (disproportionate to the volunteer's usual daily activity or exercise routine) during the malaria challenge period.

Exclusion Criteria:

  • Previous participation in any malaria vaccine trial in the last 3 years.
  • Participation in any other clinical trial involving investigational medicinal products within 30 days prior to the screening assessment.
  • Previous history of drug or alcohol abuse interfering with normal social function within one year prior to enrolment.
  • Previous vaccination with a rabies vaccine.
  • High anti-schizont antibody level as measured by ELISA at screening.
  • Intake of chronic medication, especially immunosuppressive agents (steroids, immunomodulating drugs) during the 13 weeks preceding the screening visit or during the study period.
  • Known hypersensitivity to any of the vaccine components (adjuvant or protein) or anti-malarial treatments.
  • Body mass index (BMI) of ≤18 or ≥30 Kg/m2.
  • Participants are unable to be closely followed for social, geographic or psychological reasons.
  • Any vaccination from 4 weeks prior to the 1st vaccination and (none planned) up to 8 weeks after the 3rd vaccination.
  • Any history, or evidence at screening, of clinically significant symptoms, physical signs or laboratory values suggestive of systemic disorders, including renal, hepatic, cardiovascular, pulmonary, skin, immunodeficiency, neurological, psychiatric, allergy, endocrine, malignant, haematological, infectious disease, epilepsy and other conditions, which could interfere with the interpretation of the trial results or compromise the health of the participants.
  • Abnormal electrocardiogram on screening: pathologic Q wave and significant ST-T wave changes, left ventricular hypertrophy, clinically significant arrhythmias, left bundle branch block, secondary or tertiary A-V (atrio-ventricular) heart block.
  • Any clinically significant laboratory values at screening outside of normal ranges for study participants.
  • Malaria positivity at screening (microscopy or qPCR positive).
  • Positive HIV, Hepatitis B (HBV) or Hepatitis C (HCV) tests. (The testing will only be requested on the discretion of clinician)
  • For females: Positive pregnancy test or actively breastfeeding.
  • Any recent or current systemic therapy with an antibiotic or drug with potential antimalarial activity (chloroquine, doxycycline, tetracycline, piperaquine, benzodiazepine, flunarizine, fluoxetine, tetracycline, azithromycin, clindamycin, erythromycin, hydroxychloroquine, etc.) (allowable time frame for use at investigators discretion or within a month prior to 1st vaccination or CHMI )
  • History of drug or alcohol abuse interfering with normal social function in the period of one year prior to study onset.
  • Known hypersensitivity to or contra-indications (including co-medication) for use of chloroquine, artemether-lumefantrine, Primaquine or history of severe (allergic) reactions to blood transfusion.
  • Being an employee or relative of an employee of Ifakara Health Institute.
  • Any other condition or situation that would, in the opinion of the investigator, place the volunteer at an unacceptable risk of injury or render the volunteer unable to meet the requirements of the protocol

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: Quadruple

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: Three dose SUM-101
Twelve participants will receive three monthly inoculations (on D0, D28 and D56) with the IMP, SUM-101.
Biological: SUM-101
Once randomised to either the SUM-101 or the rabies control vaccine, the participant will always receive the same dose of the same compound (150 µg MSP1 protein dissolved in 0.9% NaCl with 250 µl (5µg) of adjuvant GLA-SE and there are no dose adjustments foreseen. The three vaccine doses will be applied in 4-week intervals on day 0, day 28 and day 56.
Other: CHMI

Experimental intervention: The participants will receive a target dose of 2,800 viable intraerythrocytic P. falciparum 3D7 parasites, in a volume of 2 mL injectable saline. The erythrocytes will be thawed, resuspended and viability will be calculated. The total erythrocyte number will be between ~3.9×106 and ~5.2×108 (average: ~4.55×108) per dose with ≥80% (~3.64×108) P. falciparum ring-stage parasites and around 34% (~1.24×108) viability. This number of viable P. falciparum ring-stage parasites will be diluted to establish 2800 per syringe that will be administered. Challenge dose will be administered to all volunteers as an intravenous injection at the clinical site following instructions in an established SOP. The parasites injected in each volunteer will be quantified retrospectively using qPCR analysis.

The parasites injected in each volunteer will be quantified retrospectively using qPCR analysis. No dose adjustments are foreseen. As described in the protocol
Active Comparator: Three dose Verorab
12 participants will receive three monthly inoculations (on D0, D28 and D56) with the IMP Verorab®
Other: CHMI

Experimental intervention: The participants will receive a target dose of 2,800 viable intraerythrocytic P. falciparum 3D7 parasites, in a volume of 2 mL injectable saline. The erythrocytes will be thawed, resuspended and viability will be calculated. The total erythrocyte number will be between ~3.9×106 and ~5.2×108 (average: ~4.55×108) per dose with ≥80% (~3.64×108) P. falciparum ring-stage parasites and around 34% (~1.24×108) viability. This number of viable P. falciparum ring-stage parasites will be diluted to establish 2800 per syringe that will be administered. Challenge dose will be administered to all volunteers as an intravenous injection at the clinical site following instructions in an established SOP. The parasites injected in each volunteer will be quantified retrospectively using qPCR analysis.

The parasites injected in each volunteer will be quantified retrospectively using qPCR analysis. No dose adjustments are foreseen. As described in the protocol

Biological: Verorab®
Once randomised the participant will receive the or Verorab® and there are no dose adjustments foreseen. The three vaccine doses will be applied in 4-week intervals on day 0, day 28 and day 56.

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
Efficacy- Time to diagnosis
Time Frame: From Day 84 to Day 168
Blood-stage efficacy of the SUM-101 vaccine against 3D7 clone parasites in a CHMI model in healthy malaria-exposed adult volunteers, measured as time to diagnosis in the vaccine arm compared to controls. Time to diagnosis is defined as the number of days from challenge to treatment
From Day 84 to Day 168
Frequency of local and systemic solicited adverse events
Time Frame: After each vaccination (done on Day 0, Day 28 and Day 56) up to 7 days post-vaccination
Safety of SUM-101 vaccine in healthy malaria-exposed adults as assessed by the frequency of local and systemic solicited adverse events (AEs)
After each vaccination (done on Day 0, Day 28 and Day 56) up to 7 days post-vaccination
Frequency of local and systemic unsolicited adverse events
Time Frame: After each vaccination (done on Day 0, Day 28 and Day 56) up to 28 days post-vaccination
Safety of SUM-101 vaccine in healthy malaria-exposed adults as assessed by the frequency of local and systemic unsolicited adverse events
After each vaccination (done on Day 0, Day 28 and Day 56) up to 28 days post-vaccination
Frequency of any serious adverse events (SAE)
Time Frame: Baseline (Day 0 before 1st vaccination) to end of the follow up (Day 168)
Safety of SUM-101 vaccine in healthy malaria-exposed adults as assessed by any serious adverse events (SAE)
Baseline (Day 0 before 1st vaccination) to end of the follow up (Day 168)
Number of participants with treatment-related adverse events as assessed by safety laboratory measures of haematology and biochemistry.
Time Frame: Baseline (Day 0 before 1st vaccination) to end of the follow up (Day 168)

Number of participants with treatment-related adverse events as assessed by safety laboratory measures of haematology and biochemistry.

Changes in laboratory safety parameters as summarised as absolute values of:

Haematology: Haemoglobin, WBC (differentiation of eosinophils and neutrophils), platelets and haematocrit.

Biochemistry: parameters at screening will include: ALT, AST, total bilirubin, creatinine and glucose (random). Troponin sample will be collected before 1st vaccination (at baseline) and stored to be run retrospectively if needed in case of a cardiac event. The sample collected at the time of the cardiac event will be compared with the sample collected at baseline.

Urinalysis performed by dipstick. Proteinuria, glucose and blood.
Baseline (Day 0 before 1st vaccination) to end of the follow up (Day 168)
MSP1-specific IgG antibody levels assessed by ELISA
Time Frame: Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).
Humoral immunogenicity of SUM-101 in malaria-exposed adults assessed as MSP1-specific IgG antibody levels measured by serum ELISA in sera collected at Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).
Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).

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
Immunogenicity to MSP1-specific IgM antibody levels measured by ELISA
Time Frame: Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).
Humoral immunogenicity of SUM-101 in malaria-exposed adults assessed as MSP1-specific IgM antibody levels measured by serum ELISA in sera collected at Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).
Day 0 (pre-vaccination) and Day 84 (Pre-CHMI).
Immunogenicity assessed as antibody-mediated complement fixation activity.
Time Frame: Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)
Humoral immunogenicity of SUM-101 in malaria-exposed adults assessed as antibody-mediated complement fixation activity.
Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)
Antibody-mediated complement fixation activity
Time Frame: Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)
Humoral immunogenicity of SUM-101 in malaria-exposed adults assessed as antibody-mediated complement fixation activity.
Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)
Antibody-dependent respiratory burst (ADRB) activity
Time Frame: Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)
Humoral immunogenicity of SUM-101 in malaria-exposed adults assessed as antibody-dependent respiratory burst (ADRB) activity.
Day 0 (pre-vaccination) and Day 84 (Pre-CHMI)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Comparison of P. falciparum in vivo parasite growth rates
Time Frame: Day 84 to Day 168
Blood-stage efficacy of SUM-101 malaria vaccine candidate against 3D7 clone parasites in a CHMI model in healthy malaria-exposed adult volunteers, assessed as a comparison of P. falciparum in vivo parasite growth rates (such as parasite multiplication rate, maximum parasitemia, area under the curve, HRP2 levels or total parasites calculation and other outcomes based on parasite growth) in SUM-101 versus Verorab® arm.
Day 84 to Day 168

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.
European Vaccine Initiative

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.
Ifakara Health Institute
Luxembourg Institute of Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ally Olotu, MD, Ifakara Health Institute (IHI)

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 (Estimated)

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.
March 20, 2026

Primary Completion (Estimated)

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.
July 31, 2026

Study Completion (Estimated)

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.
December 31, 2026

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).
July 4, 2025

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.
August 12, 2025

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.
August 15, 2025

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.
November 21, 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.
November 20, 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.
July 1, 2025

More Information

Terms related to this study

Keywords

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.
  • EVI-CT-002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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