MalariaEarly Phase 1NCT05400746
A Study of the Plasmodium Falciparum Malaria Vaccine Candidate Pfs48/45 in Matrix-M Adjuvant in the UK
A Early Phase 1 study testing Pfs48/45 in Matrix-M in people with Malaria and Plasmodium Falciparum, run by University of Oxford at 1 site in United Kingdom.
Trial summary
This is an open label, single-site, first-in-human, dose-escalation Phase Ia study to assess safety and immunogenicity of the Plasmodium falciparum malaria vaccine candidate Pfs48/45 in Matrix-M adjuvant in healthy adults living in the UK Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Malaria, Plasmodium Falciparum
- What is being tested?
- Pfs48/45 in Matrix-M
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 17 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 2 Nov 2022to 19 Oct 2023
- Phase
- Early Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adult aged 18 to 45 years.
- Able and willing (in the Investigator's opinion) to comply with all study requirements.
- Willing to allow the Investigators to discuss the volunteer's medical history with their GP.
- Volunteers with the potential to become pregnant only: must practice continuous effective contraception for the duration of the study (see section 10.10).
- Agreement to refrain from blood donation for the duration of the study.
- Able and willing to provide written informed consent to participate in the trial
Who cannot join
- History of clinical malaria (any species).
- Travel to a clearly malaria endemic locality during the study period or within the preceding six months.
- Use of immunoglobulins or blood products (e.g., blood transfusion) in the last three months.
- Receipt of any vaccine in the 30 days preceding enrolment, or planned receipt of any other vaccine within 30 days following each study vaccination, with the exception of COVID-19 vaccines, which should not be received between 14 days before to 7 days after any study vaccination.
- Receipt of an investigational product in the 30 days preceding enrolment, or planned receipt during the study period.
- Concurrent involvement in another clinical trial or planned involvement during the study period.
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- Prior receipt of an investigational vaccine likely to impact on interpretation of the trial data, as assessed by the Investigator.
- 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).
- History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
- Any history of anaphylaxis in reaction to vaccinations.
- Pregnancy, lactation or intention to become pregnant during the study.
- History of cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ).
- History of serious psychiatric condition that may affect participation in the study.
- Any other serious chronic illness requiring hospital specialist supervision.
- Suspected or known current alcohol abuse as defined by an alcohol intake of greater than 25 standard UK units every week.
- Suspected or known injecting drug abuse in the 5 years preceding enrolment.
- Hepatitis B surface antigen (HBsAg) detected in serum.
- Seropositive for hepatitis C virus (antibodies to HCV) at screening (unless volunteer has taken part in a prior hepatitis C vaccine study with confirmed negative HCV antibodies prior to participation in that study, and negative HCV ribonucleic acid (RNA) PCR at screening for this study).
- Volunteers unable to be closely followed for social, geographic or psychological reasons.
- Any clinically significant abnormal finding on biochemistry or haematology blood tests, urinalysis or clinical examination. In the event of abnormal test results, confirmatory repeat tests will be requested. Procedures for identifying laboratory values meeting exclusion criteria are shown in SOP VC027.
- Any other significant disease, disorder, or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data.
- Inability of the study team to contact the volunteer's GP to confirm medical history.
- Absolute contraindications:
- Anaphylactic reaction following administration of vaccine.
- Pregnancy.
- Contraindications at that point in time (may be rescheduled):
- Acute disease at the time of vaccination. (Acute disease is defined as the presence of a moderate or severe illness with or without fever). All vaccines can be administered to persons with a minor illness such as diarrhoea, mild upper respiratory infection with or without low-grade febrile illness, i.e. temperature of ≤37.5°C/99.5°F.
- Temperature of >37.5°C (99.5°F) at the time of vaccination.
- Current COVID-19 infection, defined as ongoing symptoms with positive COVID-19 PCR swab test taken during current illness or positive COVID-19 PCR swab or rapid antigen test within preceding 7 days without symptoms. Vaccinations will be delayed by a minimum of 7 days from the date of the first positive COVID-19 PCR swab or rapid antigen test, as long as symptoms are improving or resolved. It will be at the discretion of the Investigator to withdraw a participant if they develop severe COVID-19 disease.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
CCVTM, Churchill Hospital, University of Oxford
Oxford, OX3 7LE
About this study
Official title: A Phase Ia Study to Assess Safety and Immunogenicity of the Plasmodium Falciparum Malaria Vaccine Candidate Pfs48/45 in Matrix-M Adjuvant in Healthy Adults Living in the UK
This is an open label, single-site, first-in-human, dose-escalation Phase Ia study to assess safety and immunogenicity of the Plasmodium falciparum malaria vaccine candidate Pfs48/45 in Matrix-M adjuvant in healthy adults living in the UK
Read the detailed description
Volunteers will be recruited into one of three groups (n=8-10 per group) at the Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Oxford over approximately 12 months. All volunteers will receive three dose of Pfs48/45 in 50 µg Matrix-M, administered intramuscularly and given four weeks apart. Enrolment will be staggered with clinical and safety reviews, follow-up visits and monitoring via a diary card.
- Conditions
- Malaria, Plasmodium Falciparum
- Being tested
- Pfs48/45 in Matrix-M
- Keywords
- Pfs48/45, Matrix-M
- Medical subject headings
- Malaria, Malaria, Falciparum
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pfs48/45 in Matrix-MBiological
Three doses of Pfs48/45 in Matrix-M at different doses
| Study group | Role | What they receive |
|---|---|---|
| Group 1 - low dose | Experimental | 8-10 volunteers receiving three doses of 10 µg Pfs48/45 in 50 µg Matrix-M on days 0, 28 and 56 via intramuscular injection (IM) in the deltoid region of the arm Receives: Biological: Pfs48/45 in Matrix-M |
| Group 2 - standard dose | Experimental | 8-10 volunteers receiving three doses of 50 µg Pfs48/45 in 50 µg Matrix-M on days 0, 28 and 56 via intramuscular injection (IM) in the deltoid region of the arm Receives: Biological: Pfs48/45 in Matrix-M |
| Group 3 - fractional dose | Experimental | 8-10 volunteers receiving two doses of 50 µg Pfs48/45 in 50 µg Matrix-M on days 0 and 28, followed by one dose of 10 µg Pfs48/45 in 50 µg Matrix-M on day 56 via intramuscular injection (IM) in the deltoid region of the arm Receives: Biological: Pfs48/45 in Matrix-M |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Solicited Local Reactogenicity Signs and Symptoms for 7 Days Following Each Vaccination
Occurrence of solicited local reactogenicity signs and symptoms for 7 days following each vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results
Measured: 7 days following each vaccination
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Solicited Systemic Reactogenicity Signs and Symptoms for 7 Days Following Each Vaccination
Occurrence of solicited systemic reactogenicity signs and symptoms for 7 days following each vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results.
Measured: 7 days following each vaccination
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Unsolicited Adverse Events (AEs) for 28 Days Following the Vaccination
Number of unsolicited adverse events (AEs) for 28 days following the vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results
Measured: 28 days following the vaccination
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers. Assessed Through the Number of Participants With Abnormal Laboratory Test Results
Occurrence of change from baseline laboratory tests
Measured: 28 days following vaccination
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers Assessed Through the Number of Participants With Serious Adverse Events
Occurrence of serious adverse events will be presented according to local grading scales
Measured: Whole duration of the study (8 months following initial trial vaccination)
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers.
Occurrence of AEs of special interest will be presented according to local grading scales and will be described in detail
Measured: Whole duration of the study (8 months following initial trial vaccination)
Secondary outcomes (4)
Humoral Immunogenicity of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers as Assessed by Humoral Responses to the Pfs48/45 Protein
Antibody responses to the Pfs48/45 protein will be assessed through total IgG isotypes and avidity
Measured: Days 1, 29, 57, 140 and 240
Cellular Immunogenicity of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers as Assessed by Cellular Responses to the Pfs48/45 Protein
T cell responses to Pfs48/45 will be assessed by ex vivo enzyme-linked immunospot assays (ELISpot)
Measured: Days 1, 29, 57, 140 and 240
Ex Vivo Efficacy of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers Using Direct Membrane Feeding Assays as Assessed by Transmission-reducing Activity
Transmission-reducing activity
Measured: Days 1, 29, 57, 140 and 240
Ex Vivo Efficacy of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers Using Direct Membrane Feeding Assays as Assessed by Transmission-blocking Activity
Transmission-blocking activity
Measured: Days 1, 29, 57, 140 and 240
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jun 2022
- Study start2 Nov 2022
- Primary completion19 Oct 2023
- Study completion19 Oct 2023
Why it stopped: Significant delays in vaccine adjuvant supply due to an out of specification within the context of the grant timeline. Limited safety and immunological data could be accrued from incomplete regimens.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for MalariaStudies of the same condition, open and under way.
- More trials run by University of OxfordThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 17 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Oxford
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Angela M Minassian, DPhil FRCP, Principal investigator, Center for Clinical Vaccinology and Tropical Medicine, University of Oxford
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05400746
- Sponsor's protocol ID
- VAC085
- Status last verified
- May 2023
- First submitted
- 26 May 2022
- Last updated
- 7 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase Ia Study to Assess Safety and Immunogenicity of the Plasmodium Falciparum Malaria Vaccine Candidate Pfs48/45 in Matrix-M Adjuvant in Healthy Adults Living in the UK
- ClinicalTrials.gov ID
- NCT05400746
- Acronym / sponsor ID
- VAC085
- Conditions
- Malaria, Plasmodium Falciparum
- Keywords
- Pfs48/45, Matrix-M
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Significant delays in vaccine adjuvant supply due to an out of specification within the context of the grant timeline. Limited safety and immunological data could be accrued from incomplete regimens.
- Enrolment
- 17 participants (actual)
- Lead sponsor
- University of OxfordUniversity, hospital or other
- Study start
- 2 Nov 2022 (actual)
- Primary completion
- 19 Oct 2023 (actual)
- Study completion
- 19 Oct 2023 (actual)
- First posted
- 2 Jun 2022 (actual)
- Results
- Posted 28 Mar 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is an open label, single-site, first-in-human, dose-escalation Phase Ia study to assess safety and immunogenicity of the Plasmodium falciparum malaria vaccine candidate Pfs48/45 in Matrix-M adjuvant in healthy adults living in the UK
Detailed description
Volunteers will be recruited into one of three groups (n=8-10 per group) at the Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Oxford over approximately 12 months. All volunteers will receive three dose of Pfs48/45 in 50 µg Matrix-M, administered intramuscularly and given four weeks apart. Enrolment will be staggered with clinical and safety reviews, follow-up visits and monitoring via a diary card.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Group 1 - low dose | Experimental | Biological: Pfs48/45 in Matrix-M8-10 volunteers receiving three doses of 10 µg Pfs48/45 in 50 µg Matrix-M on days 0, 28 and 56 via intramuscular injection (IM) in the deltoid region of the arm |
| Group 2 - standard dose | Experimental | Biological: Pfs48/45 in Matrix-M8-10 volunteers receiving three doses of 50 µg Pfs48/45 in 50 µg Matrix-M on days 0, 28 and 56 via intramuscular injection (IM) in the deltoid region of the arm |
| Group 3 - fractional dose | Experimental | Biological: Pfs48/45 in Matrix-M8-10 volunteers receiving two doses of 50 µg Pfs48/45 in 50 µg Matrix-M on days 0 and 28, followed by one dose of 10 µg Pfs48/45 in 50 µg Matrix-M on day 56 via intramuscular injection (IM) in the deltoid region of the arm |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Healthy adult aged 18 to 45 years.
- Able and willing (in the Investigator's opinion) to comply with all study requirements.
- Willing to allow the Investigators to discuss the volunteer's medical history with their GP.
- Volunteers with the potential to become pregnant only: must practice continuous effective contraception for the duration of the study (see section 10.10).
- Agreement to refrain from blood donation for the duration of the study.
Key exclusion criteria (29 listed)
- History of clinical malaria (any species).
- Travel to a clearly malaria endemic locality during the study period or within the preceding six months.
- Use of immunoglobulins or blood products (e.g., blood transfusion) in the last three months.
- Receipt of any vaccine in the 30 days preceding enrolment, or planned receipt of any other vaccine within 30 days following each study vaccination, with the exception of COVID-19 vaccines, which should not be received between 14 days before to 7 days after any study vaccination.
- Receipt of an investigational product in the 30 days preceding enrolment, or planned receipt during the study period.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pfs48/45 in Matrix-MThree doses of Pfs48/45 in Matrix-M at different doses | Biological | Group 1 - low dose, Group 2 - standard dose, Group 3 - fractional dose |
Primary outcome
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Solicited Local Reactogenicity Signs and Symptoms for 7 Days Following Each Vaccination
Time frame: 7 days following each vaccination
Occurrence of solicited local reactogenicity signs and symptoms for 7 days following each vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Solicited Systemic Reactogenicity Signs and Symptoms for 7 Days Following Each Vaccination
Time frame: 7 days following each vaccination
Occurrence of solicited systemic reactogenicity signs and symptoms for 7 days following each vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results.
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Unsolicited Adverse Events (AEs) for 28 Days Following the Vaccination
Time frame: 28 days following the vaccination
Number of unsolicited adverse events (AEs) for 28 days following the vaccination using e-diaries, clinical review, clinical examination (including observations) and laboratory results
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers. Assessed Through the Number of Participants With Abnormal Laboratory Test Results
Time frame: 28 days following vaccination
Occurrence of change from baseline laboratory tests
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers Assessed Through the Number of Participants With Serious Adverse Events
Time frame: Whole duration of the study (8 months following initial trial vaccination)
Occurrence of serious adverse events will be presented according to local grading scales
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers.
Time frame: Whole duration of the study (8 months following initial trial vaccination)
Occurrence of AEs of special interest will be presented according to local grading scales and will be described in detail
4 secondary outcomes
Humoral Immunogenicity of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers as Assessed by Humoral Responses to the Pfs48/45 Protein
Time frame: Days 1, 29, 57, 140 and 240
Cellular Immunogenicity of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers as Assessed by Cellular Responses to the Pfs48/45 Protein
Time frame: Days 1, 29, 57, 140 and 240
Ex Vivo Efficacy of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers Using Direct Membrane Feeding Assays as Assessed by Transmission-reducing Activity
Time frame: Days 1, 29, 57, 140 and 240
Ex Vivo Efficacy of the Pfs48/45 With Matrix-M Vaccine, When Administered to Healthy Adult Volunteers Using Direct Membrane Feeding Assays as Assessed by Transmission-blocking Activity
Time frame: Days 1, 29, 57, 140 and 240
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Angela M Minassian, DPhil FRCP principal investigator
Center for Clinical Vaccinology and Tropical Medicine, University of Oxford
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Pfs48/45 in Matrix-M in people with Malaria and Plasmodium Falciparum, run by University of Oxford at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 29 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 7 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 28 Mar 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety and Tolerability of the Pfs48/45 With Matrix-M Vaccine at Various Doses in Healthy Adult Volunteers by Assessing the Occurrence of Solicited Local Reactogenicity Signs and Symptoms for 7 Days Following Each Vaccination (time frame: 7 days following each vaccination). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Aug 2026.