MalariaPhase 1IMRASNCT01994525
Immunization Via Mosquito Bite With Radiation-attenuated Sporozoites
A Phase 1 study testing PfRAS and Challenge in people with Malaria, run by U.S. Army Medical Research and Development Command at 1 site in United States.
Trial summary
This study is to assess the safety, tolerability, and biomarkers of protection in healthy malaria-naïve adults, who will receive bites from Anopheles stephensi mosquitoes either infected with Plasmodium falciparum Sporozoites (PfRAS) (true-immunization) or noninfected (mock-immunization). Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Malaria
- What is being tested?
- PfRAS and Challenge
- Type of treatment
- Vaccines
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 54 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Jan 2014to Feb 2017
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adults (male or non-pregnant, non-breastfeeding female) 18-50 years of age (inclusive).
- Available and willing to participate for duration of study.
- Able and willing to provide written informed consent.
- Able to complete an Assessment of Understanding with a score of at least 70% correct.
- In good general health with no clinically significant health problems as established by medical history, physical exam and laboratory screening.
- Females of childbearing potential must have a negative pregnancy test at screening and agree to not become pregnant or breastfeed for the duration of the study. She must be willing to use a reliable form of contraception during the study. Reliable forms of birth control include use of condoms, diaphragm or cervical cap, birth control pills, IUD or sperm killing products.
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- Agree to refrain from blood donation (except as required in this study) for 3 years following P falciparum challenge.
- Agree not to travel to a malaria-endemic region during the study.
- Good peripheral venous access.
Who cannot join
- Positive HIV, HBsAg, or HCV serology.
- Positive sickle cell screening test, including evidence of sickle trait.
- Reactivity by CSP or AMA1 ELISpot assay or ELISA as determined by IMRAS Study Specific Procedure #204.
- Anemia (below normal reference laboratory value of hemoglobin) on screening.
- Weight less than 110 pounds (this does not apply to infectivity controls as it is a weight cut-off for subjects undergoing leukapheresis procedure)
- Any history of malaria infection or travel to a malaria endemic region within 6 months prior to first immunization.
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- History of long-term residence (> 5 years) in area known to have significant transmission of Pf [cumulative lifetime exposure].
- Use of systemic immunosuppressant pharmacotherapy for greater than 10 days within 60 days of scheduled first immunization (inhaled and topical steroids are allowed; short duration or tapered corticosteroid regimens of 10 days or less that have been discontinued prior to first immunization are allowed).
- Current significant medical condition (cardiovascular, hepatic, renal, pulmonary, or hematological) or evidence of any other serious underlying medical condition identified by medical history, physical examination, or laboratory examination (includes bleeding disorders).
- Plan for surgery between enrollment and day 28 post-challenge (minor procedures, elective corrective vision surgery, and dental procedures are allowed).
- Receipt of immunoglobulin and/or any blood products within 90 days of scheduled leukapheresis or immunization. Version 13.0 (08May2015) 70 US Government Proprietary Deleted: 8 Deleted: 08JULY2014
- Has evidence of increased cardiovascular disease risk (defined as > 5%-10%, 5-year risk) as determined by the method of Gaziano (2008). Risk factors include sex, age (years), systolic blood pressure (mm Hg), smoking status, body mass index (BMI, kg/m2), reported diabetes status, and blood pressure.
- An abnormal electrocardiogram (ECG), defined as one showing pathologic Q waves and significant ST-T wave changes; left ventricular hypertrophy; any non-sinus rhythm excluding isolated premature atrial contractions; right or left bundle branch block; or advanced (secondary or tertiary) A-V heart block.
- History of a splenectomy.
- History of any other illness or condition that, in the investigator's judgment, may substantially increase the risk associated with the subject's participation in the protocol or compromise the scientific objectives. This may include psychiatric disorders (such as personality disorders, anxiety disorders, or schizophrenia) or behavioral tendencies (including active alcohol or drug abuse) discovered during the screening process that in the opinion of the investigator would make compliance with the protocol difficult.
- History of anaphylactic or severe response to mosquito bites, retinal or visual field changes, or known allergy to the antimalarial chloroquine phosphate, which will be used to treat subjects developing malaria after CHMI.
- Participation in any study involving any investigational vaccine or drug within 30 days prior to the screening visit, or plan to participate in another investigational vaccine/drug research during or within 1 month following participation in this study.
- Use or planned use of any drug with antimalarial activity that would coincide with immunization or challenge.
- History of psoriasis or porphyria, which may be exacerbated after treatment with chloroquine.
- Anticipated use of medications known to cause drug reactions with chloroquine or atovaquone-proguanil (Malarone) such as cimetidine, metoclopramide, antacids, and kaolin during the day 7 to 28 post-challenge period.
- Any other significant findings which, in the investigator's judgment, may substantially increase the risk associated with the subject's participation in the study or compromise the scientific objectives.
Trial locations and contacts
1 site in 1 country.
United States1 site
Naval Medical Research Center Clinical Trials Center (CTC)
Bethesda, Maryland, 20889
About this study
Official title: Phase 1 Trial With Challenge to Assess the Safety and Biomarkers of Protection in Malaria-naïve Adults of Immunization Via Mosquito Bite With Radiation-Attenuated Plasmodium Falciparum Sporozoites (IMRAS)
This study is to assess the safety, tolerability, and biomarkers of protection in healthy malaria-naïve adults, who will receive bites from Anopheles stephensi mosquitoes either infected with Plasmodium falciparum Sporozoites (PfRAS) (true-immunization) or noninfected (mock-immunization).
Read the detailed description
This is a Phase 1 open-labeled study. In addition to safety and tolerability of Plasmodium falciparum Sporozoites (PfRAS), this study is a comprehensive, systems biology-based effort to identify and validate biomarkers of protection with PfRAS immunization, comparing sterility protected to nonprotected study subjects. The goal of the trial design is to achieve approximately 50% sterile protection in order to facilitate the identification of biomarkers and correlates of protection.
Following true-immunization or mock-immunization, study subjects and nonimmunized infectivity controls will receive a challenge via the bites of 5 An stephensi mosquitoes carrying infectious P falciparum sporozoites within a controlled clinical environment (controlled human malaria infection, CHMI) to determine the level of sterile protection.
- Conditions
- Malaria
- Being tested
- PfRAS, Placebo, Challenge
- Medical subject headings
- Malaria
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PfRASBiological
Also called True-immunization, PfRAS infected Anopheles stephensi mosquitoes
Radiation-attenuated Plasmodium falciparum sporozoites (PfRAS) administered by the bite of infected Anopheles stephensi mosquitoes
PlaceboBiological
Also called Mock-immunization, Noninfected Anopheles stephensi mosquites
Administered by the bite of noninfected Anopheles stephensi mosquitoes
ChallengeOther
5 infectious Anopheles stephensi mosquito bites carrying infectious Plasmodium falciparum sporozoites within a controlled clinical environment.
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1: PfRAS-infected | Experimental | 5 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes (true-immunization). The target dose is 960 infectious bites.
Challenge occurs 3 weeks after final immunization. Receives: Biological: PfRAS; Other: Challenge |
| Cohort 1: Noninfected | Placebo comparator | Placebo immunization. 5 doses of approximately 200 noninfected bites (200-400 bites total) from irradiated uninfected mosquitoes (mock-immunization). The target dose is 960 noninfected bites.
Challenge occurs 3 weeks after final immunization. Receives: Biological: Placebo; Other: Challenge |
| Cohort 1: Nonimmunized | Other | No protective intervention given.
Challenge occurs directly after screening. Receives: Other: Challenge |
| Cohort 2: PfRAS-infected | Experimental | 3 to 7 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes (true-immunization). The target dose is dependent on protection results in cohort 1.
Challenge occurs 3 weeks after final immunization. Receives: Biological: PfRAS; Other: Challenge |
| Cohort 2: Noninfected | Placebo comparator | Placebo. 3 to 7 doses of approximately 200 noninfected bites (200-400 bites total) from irradiated, uninfected mosquitoes (true-immunization). The target dose is dependent on protection results in cohort 1.
Challenge occurs 3 weeks after final immunization. Receives: Biological: Placebo; Other: Challenge |
| Cohort 2: Nonimmunized | Other | No protective intervention given.
Challenge occurs directly after screening. Receives: Other: Challenge |
| Hyperimmunity PfRAS-infected | Experimental | Cohort 1 sub-cohort
3 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes. This arm will receive the first 3 immunizations of Cohort 2.
Challenge occurs at the same time as Cohort 2 (3-20 weeks after the final immunization) Receives: Biological: PfRAS; Other: Challenge |
What is being measured
The primary outcome is the main question the study is designed to answer.
Solicited adverse events
Occurrence of solicited adverse events (AE) from administration of study immunization (PfRAS)
Measured: 7 days
Unsolicited adverse events
Occurrence of unsolicited adverse events (AEs) from administration of immunization (PfRAS)
Measured: 14 days
Laboratory adverse events
Occurrence of laboratory AEs from administration of study immunization (PfRAS)
Measured: 7 days
Serious adverse events
Occurrence of serious adverse events (SAEs) from administration of immunization (PfRAS)
Measured: 52 weeks
Signs and symptoms related to malaria infection
Occurrence of signs and symptoms related to malaria infection starting 7 days post-Controlled Human Malaria Infection (CHMI) (these will not be recorded as adverse events because they are expected as a result of malaria infection)
Measured: 7 days
Parasitemia
Development of parasitemia and time to parasitemia after malaria challenge
Measured: 52 weeks
Secondary outcomes (3)
Identify and validate immunological PBMC biomarkers
Compare Peripheral Blood Mononuclear Cell(s) (PBMC) read-outs between protected and nonprotected subjects and between immunized and mock-immunized subjects.
Measured: 52 weeks
Identify and validate immunological serum biomarkers
Compare serum read-outs between protected and nonprotected subjects and between immunized and mock-immunized subjects.
Measured: 52 weeks
Identify and validate whole blood immunological biomarkers
Compare whole blood read-outs between protected and nonprotected subjects and between immunized and mock-immunized subjects.
Measured: 52 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2013 (estimated)
- Study start24 Jan 2014
- Primary completion20 Dec 2016
- Study completionFeb 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for MalariaStudies of the same condition, open and under way.
- 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
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 54 participants (actual)
Sponsor and investigators
- Lead sponsor
- U.S. Army Medical Research and Development Command
- Sponsor type
- US federal agency
- Collaborators
- Seattle Children's Hospital, Bill and Melinda Gates Foundation
- Responsible party
- Sponsor
- Investigators
- Nimfa Teneza-Mora, MD, Principal investigator, Naval Medical Research Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01994525
- Sponsor's protocol ID
- S-12-22
- Acronym
- IMRAS
- Status last verified
- Mar 2019
- First submitted
- 19 Nov 2013
- Last updated
- 17 Sep 2019
- Results posted
- No
- Data monitoring committee
- No
Publications
Oyong DA, Duffy FJ, Neal ML, Du Y, Carnes J, Schwedhelm KV, Hertoghs N, Jun SH, Miller H, Aitchison JD, De Rosa SC, Newell EW, McElrath MJ, McDermott SM, Stuart KD. Distinct immune responses associated with vaccination status and protection outcomes after malaria challenge. PLoS Pathog. 2023 May 17;19(5):e1011051. doi: 10.1371/journal.ppat.1011051. eCollection 2023 May.
PubMed 37195999Du Y, Hertoghs N, Duffy FJ, Carnes J, McDermott SM, Neal ML, Schwedhelm KV, McElrath MJ, De Rosa SC, Aitchison JD, Stuart KD. Systems analysis of immune responses to attenuated P. falciparum malaria sporozoite vaccination reveals excessive inflammatory signatures correlating with impaired immunity. PLoS Pathog. 2022 Feb 2;18(2):e1010282. doi: 10.1371/journal.ppat.1010282. eCollection 2022 Feb.
PubMed 35108339Sedegah M, Hollingdale MR, Ganeshan H, Belmonte M, Huang J, Belmonte A, Inoue S, Velasco R, Hickey B, Teneza-Mora N, Lumsden J, Reyes S, Banania JG, Reyes A, Guzman I, Richie TL, Epstein JE, Villasante E. IMRAS-Immunization with radiation-attenuated Plasmodium falciparum sporozoites by mosquito bite: Cellular immunity to sporozoites, CSP, AMA1, TRAP and CelTOS. PLoS One. 2021 Aug 20;16(8):e0256396. doi: 10.1371/journal.pone.0256396. eCollection 2021.
PubMed 34415964Hickey B, Teneza-Mora N, Lumsden J, Reyes S, Sedegah M, Garver L, Hollingdale MR, Banania JG, Ganeshan H, Dowler M, Reyes A, Tamminga C, Singer A, Simmons A, Belmonte M, Belmonte A, Huang J, Inoue S, Velasco R, Abot S, Vasquez CS, Guzman I, Wong M, Twomey P, Wojnarski M, Moon J, Alcorta Y, Maiolatesi S, Spring M, Davidson S, Chaudhury S, Villasante E, Richie TL, Epstein JE. IMRAS-A clinical trial of mosquito-bite immunization with live, radiation-attenuated P. falciparum sporozoites: Impact of immunization parameters on protective efficacy and generation of a repository of immunologic reagents. PLoS One. 2020 Jun 17;15(6):e0233840. doi: 10.1371/journal.pone.0233840. eCollection 2020.
PubMed 32555601
Study at a glance
From the registry record, last updated by the sponsor on 17 Sep 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase 1 Trial With Challenge to Assess the Safety and Biomarkers of Protection in Malaria-naïve Adults of Immunization Via Mosquito Bite With Radiation-Attenuated Plasmodium Falciparum Sporozoites (IMRAS)
- ClinicalTrials.gov ID
- NCT01994525
- Acronym / sponsor ID
- IMRAS / S-12-22
- Conditions
- Malaria
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 54 participants (actual)
- Lead sponsor
- U.S. Army Medical Research and Development CommandUS federal agency
- Collaborators
- Seattle Children's Hospital, Bill and Melinda Gates Foundation
- Study start
- 24 Jan 2014 (actual)
- Primary completion
- 20 Dec 2016 (actual)
- Study completion
- Feb 2017 (actual)
- First posted
- 25 Nov 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is to assess the safety, tolerability, and biomarkers of protection in healthy malaria-naïve adults, who will receive bites from Anopheles stephensi mosquitoes either infected with Plasmodium falciparum Sporozoites (PfRAS) (true-immunization) or noninfected (mock-immunization).
Detailed description
This is a Phase 1 open-labeled study. In addition to safety and tolerability of Plasmodium falciparum Sporozoites (PfRAS), this study is a comprehensive, systems biology-based effort to identify and validate biomarkers of protection with PfRAS immunization, comparing sterility protected to nonprotected study subjects. The goal of the trial design is to achieve approximately 50% sterile protection in order to facilitate the identification of biomarkers and correlates of protection.
Following true-immunization or mock-immunization, study subjects and nonimmunized infectivity controls will receive a challenge via the bites of 5 An stephensi mosquitoes carrying infectious P falciparum sporozoites within a controlled clinical environment (controlled human malaria infection, CHMI) to determine the level of sterile protection.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| Cohort 1: PfRAS-infected | Experimental | Biological: PfRAS, Other: Challenge5 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes (true-immunization). The target dose is 960 infectious bites. Challenge occurs 3 weeks after final immunization. |
| Cohort 1: Noninfected | Placebo comparator | Biological: Placebo, Other: ChallengePlacebo immunization. 5 doses of approximately 200 noninfected bites (200-400 bites total) from irradiated uninfected mosquitoes (mock-immunization). The target dose is 960 noninfected bites. Challenge occurs 3 weeks after final immunization. |
| Cohort 1: Nonimmunized | Other | Other: ChallengeNo protective intervention given. Challenge occurs directly after screening. |
| Cohort 2: PfRAS-infected | Experimental | Biological: PfRAS, Other: Challenge3 to 7 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes (true-immunization). The target dose is dependent on protection results in cohort 1. Challenge occurs 3 weeks after final immunization. |
| Cohort 2: Noninfected | Placebo comparator | Biological: Placebo, Other: ChallengePlacebo. 3 to 7 doses of approximately 200 noninfected bites (200-400 bites total) from irradiated, uninfected mosquitoes (true-immunization). The target dose is dependent on protection results in cohort 1. Challenge occurs 3 weeks after final immunization. |
| Cohort 2: Nonimmunized | Other | Other: ChallengeNo protective intervention given. Challenge occurs directly after screening. |
| Hyperimmunity PfRAS-infected | Experimental | Biological: PfRAS, Other: ChallengeCohort 1 sub-cohort 3 doses (immunizations) of approximately 200 infectious bites (200-400 bites total) from PfRAS-infected mosquitoes. This arm will receive the first 3 immunizations of Cohort 2. Challenge occurs at the same time as Cohort 2 (3-20 weeks after the final immunization) |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Healthy adults (male or non-pregnant, non-breastfeeding female) 18-50 years of age (inclusive).
- Available and willing to participate for duration of study.
- Able and willing to provide written informed consent.
- Able to complete an Assessment of Understanding with a score of at least 70% correct.
- In good general health with no clinically significant health problems as established by medical history, physical exam and laboratory screening.
Key exclusion criteria (21 listed)
- Positive HIV, HBsAg, or HCV serology.
- Positive sickle cell screening test, including evidence of sickle trait.
- Reactivity by CSP or AMA1 ELISpot assay or ELISA as determined by IMRAS Study Specific Procedure #204.
- Anemia (below normal reference laboratory value of hemoglobin) on screening.
- Weight less than 110 pounds (this does not apply to infectivity controls as it is a weight cut-off for subjects undergoing leukapheresis procedure)
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 |
|---|---|---|
| PfRASAlso: True-immunization, PfRAS infected Anopheles stephensi mosquitoesRadiation-attenuated Plasmodium falciparum sporozoites (PfRAS) administered by the bite of infected Anopheles stephensi mosquitoes | Biological | Cohort 1: PfRAS-infected, Cohort 2: PfRAS-infected, Hyperimmunity PfRAS-infected |
| PlaceboAlso: Mock-immunization, Noninfected Anopheles stephensi mosquitesAdministered by the bite of noninfected Anopheles stephensi mosquitoes | Biological | Cohort 1: Noninfected, Cohort 2: Noninfected |
| Challenge5 infectious Anopheles stephensi mosquito bites carrying infectious Plasmodium falciparum sporozoites within a controlled clinical environment. | Other | Cohort 1: Nonimmunized, Cohort 1: Noninfected, Cohort 1: PfRAS-infected, Cohort 2: Nonimmunized, Cohort 2: Noninfected, Cohort 2: PfRAS-infected, Hyperimmunity PfRAS-infected |
Primary outcome
Solicited adverse events
Time frame: 7 days
Occurrence of solicited adverse events (AE) from administration of study immunization (PfRAS)
Unsolicited adverse events
Time frame: 14 days
Occurrence of unsolicited adverse events (AEs) from administration of immunization (PfRAS)
Laboratory adverse events
Time frame: 7 days
Occurrence of laboratory AEs from administration of study immunization (PfRAS)
Serious adverse events
Time frame: 52 weeks
Occurrence of serious adverse events (SAEs) from administration of immunization (PfRAS)
Signs and symptoms related to malaria infection
Time frame: 7 days
Occurrence of signs and symptoms related to malaria infection starting 7 days post-Controlled Human Malaria Infection (CHMI) (these will not be recorded as adverse events because they are expected as a result of malaria infection)
Parasitemia
Time frame: 52 weeks
Development of parasitemia and time to parasitemia after malaria challenge
3 secondary outcomes
Identify and validate immunological PBMC biomarkers
Time frame: 52 weeks
Identify and validate immunological serum biomarkers
Time frame: 52 weeks
Identify and validate whole blood immunological biomarkers
Time frame: 52 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Sep 2019.
- Derived from this study: PubMed 37195999Oyong DA, Duffy FJ, Neal ML, Du Y, Carnes J, Schwedhelm KV, Hertoghs N, Jun SH, Miller H, Aitchison JD, De Rosa SC, Newell EW, McElrath MJ, McDermott SM, Stuart KD. Distinct immune responses associated with vaccination status and protection outcomes after malaria challenge. PLoS Pathog. 2023 May 17;19(5):e1011051. doi: 10.1371/journal.ppat.1011051. eCollection 2023 May.
- Derived from this study: PubMed 35108339Du Y, Hertoghs N, Duffy FJ, Carnes J, McDermott SM, Neal ML, Schwedhelm KV, McElrath MJ, De Rosa SC, Aitchison JD, Stuart KD. Systems analysis of immune responses to attenuated P. falciparum malaria sporozoite vaccination reveals excessive inflammatory signatures correlating with impaired immunity. PLoS Pathog. 2022 Feb 2;18(2):e1010282. doi: 10.1371/journal.ppat.1010282. eCollection 2022 Feb.
- Derived from this study: PubMed 34415964Sedegah M, Hollingdale MR, Ganeshan H, Belmonte M, Huang J, Belmonte A, Inoue S, Velasco R, Hickey B, Teneza-Mora N, Lumsden J, Reyes S, Banania JG, Reyes A, Guzman I, Richie TL, Epstein JE, Villasante E. IMRAS-Immunization with radiation-attenuated Plasmodium falciparum sporozoites by mosquito bite: Cellular immunity to sporozoites, CSP, AMA1, TRAP and CelTOS. PLoS One. 2021 Aug 20;16(8):e0256396. doi: 10.1371/journal.pone.0256396. eCollection 2021.
- Derived from this study: PubMed 32555601Hickey B, Teneza-Mora N, Lumsden J, Reyes S, Sedegah M, Garver L, Hollingdale MR, Banania JG, Ganeshan H, Dowler M, Reyes A, Tamminga C, Singer A, Simmons A, Belmonte M, Belmonte A, Huang J, Inoue S, Velasco R, Abot S, Vasquez CS, Guzman I, Wong M, Twomey P, Wojnarski M, Moon J, Alcorta Y, Maiolatesi S, Spring M, Davidson S, Chaudhury S, Villasante E, Richie TL, Epstein JE. IMRAS-A clinical trial of mosquito-bite immunization with live, radiation-attenuated P. falciparum sporozoites: Impact of immunization parameters on protective efficacy and generation of a repository of immunologic reagents. PLoS One. 2020 Jun 17;15(6):e0233840. doi: 10.1371/journal.pone.0233840. eCollection 2020.
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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.
Nimfa Teneza-Mora, MD principal investigator
Naval Medical Research Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing PfRAS and Challenge in people with Malaria, run by U.S. Army Medical Research and Development Command at 1 site in United States.
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 9 inclusion and 21 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: finished, as of the sponsor's last update on 17 Sep 2019. 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 States. 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. Some participants in this study may receive a placebo. 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?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Solicited adverse events (time frame: 7 days). 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?
On the ClinicalTrials.gov record for NCT01994525, which also lists 4 linked publications.
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 17 Sep 2019.