SchistosomiasisPhase 1/2NCT03910972
Sm-TSP-2 Schistosomiasis Vaccine in Healthy Ugandan Adults
A Phase 1/2 study testing Sm-TSP-2/Alhydrogel® vaccine, Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 and ENGERIX-B Hepatitis B Vaccine in people with Schistosomiasis and Schistosoma Mansoni, run by Baylor College of Medicine at 1 site in Uganda.
Trial summary
The study will recruit up to 290 healthy adult males and non-pregnant females into a two-part clinical trial of a vaccine to protect against schistosomiasis caused by infection with S. mansoni. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Schistosomiasis, Schistosoma Mansoni
- What is being tested?
- Sm-TSP-2/Alhydrogel® vaccine, Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 and ENGERIX-B Hepatitis B Vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 290 participants
- Where
- 1 siteUganda
- Study dates
- 7 Oct 2019to 13 Nov 2024
- Phase
- Phase 1/2
- 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Provide written informed consent prior to any study procedures.
- Able to understand and comply with planned study procedures and be available for all study visits.
- Male or non-pregnant female aged 18 to 45, inclusive at the time of enrollment.
- Are in good health, as determined by vital signs (oral temperature, pulse, and blood pressure), medical history, and brief physical examination at screening.
- Vital signs (oral temperature, pulse, and blood pressure) are all within normal protocol-defined ranges.
- Laboratory tests (alanine aminotransferase [ALT], creatinine, white blood cell count (WBC), hemoglobin, and platelets) are all within protocol-defined reference ranges.
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- Urinalysis with no greater than trace protein and negative for glucose.
- Female subjects of childbearing potential must agree to practice highly effective contraception for a minimum of 30 days prior to first vaccination and for 30 days after last vaccination.
- Female subjects of childbearing potential must have a negative urine pregnancy test within 24 hours prior to study vaccination.
- Able to correctly answer all questions on the informed consent comprehension questionnaire.
Who cannot join
- Has the intention to become pregnant within 5 months after enrollment in this study.
- Female subjects who are breastfeeding or plan to breastfeed at any given time from the first study vaccination until 30 days after their last study vaccination.
- Has an acute illness, including a documented oral temperature of 38.0°C or greater, within 72 hours prior to vaccination.
- Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
- Is immunosuppressed as a result of an underlying illness or treatment.
- Using or intends to continue using oral or parenteral steroids, high-dose inhaled steroids (>800 μg/day of beclomethasone dipropionate or equivalent) or other immunosuppressive or cytotoxic drugs.
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- Positive test for HIV infection.
- Volunteer has had a history of alcohol or illicit drug abuse during the past 23 months.
- Received immunoglobulin or other blood products (with exception of Rho D immunoglobulin) within 90 days prior to study vaccination.
- History of a severe allergic reaction or anaphylaxis to known components of the study vaccines.
- Has an acute or chronic medical condition that, in the opinion of the investigator, would render participation in this study unsafe or would interfere with the evaluation of responses.
- History of splenectomy.
- Is participating or plans to participate in another clinical trial with an interventional agent during the duration of the study.
- Received any licensed live vaccine within 30 days or any licensed inactivated vaccine within 14 days prior to the first study vaccination.
- Planned receipt of any vaccine from the first study vaccination through 28 days after the last study vaccination.
- Has any diagnosis, current or past, of schizophrenia, bipolar disease, or other psychiatric diagnosis that may interfere with subject compliance or safety evaluations.
- Has any condition that would, in the opinion of the site investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol.
- Anti-Sm-TSP-2 IgE antibody level above ELISA reactivity threshold.
- Part A Only:
- Positive hepatitis B surface antigen (HBsAg).
- Positive confirmatory test for hepatitis C virus (HCV) infection.
- Part B Only:
- Negative for Schistosoma mansoni eggs, as assessed by the Kato Katz fecal thick smear during screening.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Phase I/II Study of the Safety, Immunogenicity, and Efficacy of Sm-TSP-2/Alhydrogel® With or Without AP 10-701 for Intestinal Schistosomiasis in Healthy Ugandan Adults
The study will recruit up to 290 healthy adult males and non-pregnant females into a two-part clinical trial of a vaccine to protect against schistosomiasis caused by infection with S. mansoni. Two formulations of the Sm-TSP-2 vaccine will be tested: one using Alhydrogel® only, and one using Alhydrogel® plus AP 10-701, each at 3 different doses of antigen: 10mcg, 30mcg, and 100mcg.
The first part of the study will be a Phase I dose-escalation safety and immunogenicity study followed by a Phase IIb trial in which a larger number of adults will be enrolled to assess the impact of the vaccine on infection with S. mansoni. The impact of the vaccine on infection with S. haematobium will also be assessed although this will be exploratory given that potential cross-protection against this species is only hypothetical at this point.
Read the detailed description
The study will recruit up to 290 healthy adult males and non-pregnant females into a two-part clinical trial of a vaccine to protect against schistosomiasis caused by infection with S. mansoni. Two formulations of the Sm-TSP-2 vaccine will be tested: one using Alhydrogel® only, and one using Alhydrogel® plus AP 10-701, each at 3 different doses of antigen: 10mcg, 30mcg, and 100mcg.
The first part of the study will be a Phase I dose-escalation safety and immunogenicity study followed by a Phase IIb trial in which a larger number of adults will be enrolled to assess the impact of the vaccine on infection with S. mansoni. The impact of the vaccine on infection with S. haematobium will also be assessed although this will be exploratory given that potential cross-protection against this species is only hypothetical at this point.
Part A: double blind (within cohort), randomized, controlled, dose-escalation Phase 1b clinical trial in S. mansoni exposed adults living in the area of Kampala, Uganda. In each of 3 cohorts, subjects will be randomly assigned to 1 of 3 groups: Sm-TSP-2/Alhydrogel®, Sm-TSP-2/Alhydrogel®/AP 10-701, or the licensed Hepatitis B vaccine (up to 12 subjects per study vaccine group and 6 subjects in the Hepatitis B vaccine group). Subjects will receive three doses of the assigned vaccine delivered intramuscularly at approximately Days 0, 56, and 112.
Safety will be measured from the time of each study vaccination (Days 0, 56, 112 [Visits 2, 7, 12]) through 7 days after each study vaccination by the occurrence of solicited injection site and systemic reactogenicity events. Unsolicited non-serious adverse events (AEs) will be collected from the time of each study vaccination through approximately 28 days after each study vaccination. New-onset chronic medical conditions (including adverse events of special interest [AESI]) and serious adverse events (SAEs) will be collected from the time of the first study vaccination (Day 0 [Visit 2]) through approximately 9 months after the third study vaccination (Day 380 [Visit 19]). Clinical laboratory evaluations for safety will be performed on venous blood collected approximately 7 days after each study vaccination.
Immunogenicity testing will include IgG antibody responses to Sm-TSP-2 by a qualified indirect ELISA on serum obtained prior to each study vaccination (Days 0, 56, 112) and at time points after each vaccination.
Ninety subjects will be enrolled into 3 groups of 30. Recruitment and enrollment into the study will occur on an ongoing basis, with each group being recruited and vaccinated in sequence.
Part A of the study is a dose escalation trial in which escalation to the next dose cohort will be determined based on evaluation of pre-defined escalation criteria, which will be evaluated 7 days after all subjects in the currently active cohort have received their first dose of vaccine. Within each cohort, the assignment to Alhydrogel®, Alhydrogel®/AP 10-701, or Hepatitis B vaccine will be randomized and double-blinded (i.e., neither the subject nor the investigator will be aware of the formulation assigned). The study will proceed as follows:
- Cohort 1, N=30 [10mcg Sm-TSP-2/Alhydrogel® (n=12) or 10mcg Sm-TSP-2/Alhydrogel®/ AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to the remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Make escalation decision
- Cohort 2, N=30 [30mcg Sm-TSP-2/Alhydrogel® (n=12) or 30mcg Sm-TSP-2/Alhydrogel®/AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to the remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Make escalation decision
- Cohort 3, N=30 [100mcg Sm-TSP-2/Alhydrogel® (n=12) or 100mcg Sm-TSP-2/Alhydrogel®/AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Complete follow-up for all subjects
- Close the study
Part B: double blind, randomized, controlled, dose-escalation Phase IIb clinical trial in adults living in the area of Kampala, Uganda, who reside in S. mansoni endemic areas with greater than or equal to 25% prevalence in children aged 5-15 years of age. In this part of the study, up to 200 eligible Schistosoma-positive (by Kato Katz fecal thick smear or CAA) adult volunteers will be progressively enrolled and randomized to receive either Sm-TSP-2/Alhydrogel® (with or without AP 10-701) or the Hepatitis B comparator vaccine, in a 1:1 fashion. The dose and formulation (i.e., with or without the point-of-injection addition of AP 10-701) of Sm-TSP-2/Alhydrogel® that will be tested in this part of the study will be chosen based on the interim results of Part A of the trial after all participants have received their third dose of vaccine. All participants in Part B will be treated with praziquantel prior to receipt of the first vaccination.
Interim safety and anti-Sm-TSP-2 IgG antibody results up to and including Day 126 of Part A of the trial will be evaluated to determine the dose that will be tested in Part B.
Two hundred subjects will be enrolled in Part B. The 12 subjects in Part A who received the same dose/formulation of Sm-TSP-2/Alhydrogel® that is chosen for Part B will be offered the opportunity to transition to Part B for the remainder of their participation in the study.
Recruitment and enrollment into the study will occur on an ongoing basis, with participants being recruited, randomized and vaccinated in sequence. Within Part B, the assignment to Sm-TSP-2/Alhydrogel® or Hepatitis B vaccine will be randomized and double-blinded (i.e., neither the subject nor the investigator will be aware of the formulation assigned). Part B of the study will proceed as follows:
- Cohort 4, N=200 [Sm-TSP-2/Alhydrogel® [dose and formulation TBD] (n=100) or Hepatitis B vaccine (n=100)]
Subjects will receive three doses of the assigned vaccine delivered intramuscularly at approximately Days 0, 56, and 112.
Safety will be measured from the time of each study vaccination (Days 0, 56, 112 [Visits 2, 7, 12]) through 7 days after each study vaccination by the occurrence of solicited injection site and systemic reactogenicity events. Unsolicited non-serious adverse events (AEs) will be collected from the time of each study vaccination through approximately 28 days after each study vaccination. New-onset chronic medical conditions (including adverse events of special interest [AESI]) and serious adverse events (SAEs) will be collected from the time of the first study vaccination (Day 0 [Visit 2]) through approximately 23 months after the third study vaccination (Day 800 [Visit 21]). Clinical laboratory evaluations for safety will be performed on venous blood collected approximately 7 days after each study vaccination.
Immunogenicity testing will include IgG antibody responses to Sm-TSP-2 by a qualified indirect ELISA on serum obtained prior to each study vaccination (Days 0, 56, 112) and at time points after each vaccination.
Efficacy will be evaluated by measuring the impact of vaccination with Sm-TSP-2/Alhydrogel® on fecal and urine Schistosoma egg counts and CAA positivity. After final vaccination, fecal and urine samples will be collected at 12 and 23 months following the final vaccination to determine rates and intensities of re-infection. The primary endpoint to determine the impact of vaccination on infection with S. mansoni will be incidence of infection as determined by a positive CAA test or Kato-Katz fecal thick smear. The impact of vaccination on infection with S. haematobium will be assessed as an exploratory endpoint, by means of urine microscopy for schistosome eggs.
- Conditions
- Schistosomiasis, Schistosoma Mansoni
- Being tested
- Sm-TSP-2/Alhydrogel® vaccine, Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701, ENGERIX-B Hepatitis B Vaccine
- Medical subject headings
- Schistosomiasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sm-TSP-2/Alhydrogel® vaccineBiological
The Sm-TSP-2/Alhydrogel® candidate vaccine contains recombinant Sm-TSP-2 adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10mM imidazole buffer containing 2mM phosphate and 15% sucrose, with pH 7.4 ± 0.1. The final concentrations of Sm-TSP-2 and Alhydrogel® in the drug product are 0.1mg/ml and 0.8mg/ml respectively.
Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701Biological
The Sm-TSP-2/Alhydrogel® candidate vaccine co-administered with the immunostimulant, AP 10-701. b) AP 10-701, also known as Gluco-Pyranosylphospho-Lipid A Aqueous Formulation (GLA-AF), is a Toll-like Receptor-4 agonist. Point-of-injection formulations with this immunostimulant will be prepared immediately prior to vaccination by adding an appropriate volume of AP 10-701 to Sm-TSP-2/Alhydrogel® and withdrawing an appropriate volume to administer the desired amount of Sm-TSP-2 plus 5µg GLA-AF.
ENGERIX-B Hepatitis B VaccineBiological
Recombinant hepatitis B vaccine containing 10 mcg recombinant hepatitis B surface antigen per dose
| Study group | Role | What they receive |
|---|---|---|
| Part A, Group A (Sm-TSP-2/Alhydrogel 10 mcg) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 10 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine |
| Part A, Group B (Sm-TSP-2/Alhydrogel 10 mcg + AP 10-701) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 10 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 |
| Part A, Group C (Sm-TSP-2/Alhydrogel 30 mcg) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 30 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine |
| Part A, Group D (Sm-TSP-2/Alhydrogel 30 mcg + AP 10-701) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 30 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 |
| Part A, Group E (Sm-TSP-2/Alhydrogel 100 mcg) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 100 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine |
| Part A, Group F (Sm-TSP-2/Alhydrogel 100 mcg + AP 10-701) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 100 mcg dose Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 |
| Part A, Group G (HBV) | Active comparator | Hepatitis B Vaccine Receives: Biological: ENGERIX-B Hepatitis B Vaccine |
| Part B, Group H (Sm-TSP-2/Alhydrogel +/- AP 10-701) | Experimental | Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine, with or without AP 10-701, dose and formulation determined in Part A Receives: Biological: Sm-TSP-2/Alhydrogel® vaccine |
| Part B, Group I (HBV) | Active comparator | Hepatitis B Vaccine Receives: Biological: ENGERIX-B Hepatitis B Vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Tolerability: frequency of local and systemic reactogenicity events
Frequency of solicited injection site and systemic reactogenicity, graded by severity, on the day of each study vaccination through 7 days after each study vaccination.
Measured: 7 days post-vaccination
Safety and Tolerability: frequency of unsolicited adverse events
Frequency of unsolicited adverse events, graded by severity, from the time of each study vaccination through approximately 1 month after each study vaccination.
Measured: 28 days post-vaccination
Safety and Tolerability: frequency of vaccine-related Serious Adverse Events
Frequency of study vaccine-related Serious Adverse Events from the time of the first study vaccination through the final study visit.
Measured: 23 months
Safety and Tolerability: frequency of clinical safety laboratory adverse events
Frequency of clinical safety laboratory adverse events measured 7 days after each vaccination
Measured: 7 days post-vaccination
Safety and Tolerability: frequency of new-onset chronic medical conditions
Frequency of new-onset chronic medical conditions, including Adverse Events of Special Interest, through the final study visit
Measured: 23 months
Efficacy: proportion of subjects with detectable S. mansoni eggs
Proportion of subjects with detectable S. mansoni eggs at 12 and 23 months in fecal samples, as determined by Kato Katz fecal thick smear.
Measured: 12 and 23 months
Efficacy: mean S. mansoni eggs per gram of feces
Mean S. mansoni eggs per gram as determined by fecal microscopy (Kato Katz fecal thick smear) at 12 and 23 months.
Measured: 12 and 23 months
Efficacy: Proportion of subjects with a positive CAA test
Proportion of subjects with a positive CAA test at 12 and 23 months.
Measured: 12 and 23 months
Secondary outcomes (2)
Immunogenicity: peak anti-Sm-TSP-2 IgG level
IgG level by qualified indirect ELISA on approximately Day 126
Measured: Day 126
Immunogenicity: anti-Sm-TSP-2 IgG levels over time
IgG antibody response measured by qualified indirect ELISA
Measured: Approximately 14 days after doses one and two and at Days 200, 290, 380 (Parts A and B) after final dose, and at Days 548, and 800 (Part B) after final dose.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Apr 2019
- Study start7 Oct 2019
- Primary completion13 Nov 2024
- Study completion13 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SchistosomiasisStudies of the same condition, open and under way.
- More trials run by Baylor College of MedicineThe 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
- Phase 1/2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 290 participants (actual)
Sponsor and investigators
- Lead sponsor
- Baylor College of Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- George Washington University, Makerere University Walter Reed Project
- Responsible party
- Principal investigator, Maria Elena Bottazzi PhD, Baylor College of Medicine
- Investigators
- Hannah Kibuuka, MD, Principal investigator, Makerere University Walter Reed Project
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03910972
- Sponsor's protocol ID
- H-45791
- Other IDs
- TSP-18-03
- Status last verified
- Nov 2025
- First submitted
- 9 Apr 2019
- Last updated
- 4 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data related to primary and secondary objectives will be made available within 12 months of finalization of the Clinical Study Report.
Study at a glance
From the registry record, last updated by the sponsor on 4 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I/II Study of the Safety, Immunogenicity, and Efficacy of Sm-TSP-2/Alhydrogel® With or Without AP 10-701 for Intestinal Schistosomiasis in Healthy Ugandan Adults
- ClinicalTrials.gov ID
- NCT03910972
- Acronym / sponsor ID
- H-45791
- Conditions
- Schistosomiasis, Schistosoma Mansoni
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 290 participants (actual)
- Lead sponsor
- Baylor College of MedicineUniversity, hospital or other
- Collaborators
- George Washington University, Makerere University Walter Reed Project
- Study start
- 7 Oct 2019 (actual)
- Primary completion
- 13 Nov 2024 (actual)
- Study completion
- 13 Nov 2024 (actual)
- First posted
- 10 Apr 2019 (actual)
- 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.
The study will recruit up to 290 healthy adult males and non-pregnant females into a two-part clinical trial of a vaccine to protect against schistosomiasis caused by infection with S. mansoni. Two formulations of the Sm-TSP-2 vaccine will be tested: one using Alhydrogel® only, and one using Alhydrogel® plus AP 10-701, each at 3 different doses of antigen: 10mcg, 30mcg, and 100mcg.
The first part of the study will be a Phase I dose-escalation safety and immunogenicity study followed by a Phase IIb trial in which a larger number of adults will be enrolled to assess the impact of the vaccine on infection with S. mansoni. The impact of the vaccine on infection with S. haematobium will also be assessed although this will be exploratory given that potential cross-protection against this species is only hypothetical at this point.
Detailed description
The study will recruit up to 290 healthy adult males and non-pregnant females into a two-part clinical trial of a vaccine to protect against schistosomiasis caused by infection with S. mansoni. Two formulations of the Sm-TSP-2 vaccine will be tested: one using Alhydrogel® only, and one using Alhydrogel® plus AP 10-701, each at 3 different doses of antigen: 10mcg, 30mcg, and 100mcg.
The first part of the study will be a Phase I dose-escalation safety and immunogenicity study followed by a Phase IIb trial in which a larger number of adults will be enrolled to assess the impact of the vaccine on infection with S. mansoni. The impact of the vaccine on infection with S. haematobium will also be assessed although this will be exploratory given that potential cross-protection against this species is only hypothetical at this point.
Part A: double blind (within cohort), randomized, controlled, dose-escalation Phase 1b clinical trial in S. mansoni exposed adults living in the area of Kampala, Uganda. In each of 3 cohorts, subjects will be randomly assigned to 1 of 3 groups: Sm-TSP-2/Alhydrogel®, Sm-TSP-2/Alhydrogel®/AP 10-701, or the licensed Hepatitis B vaccine (up to 12 subjects per study vaccine group and 6 subjects in the Hepatitis B vaccine group). Subjects will receive three doses of the assigned vaccine delivered intramuscularly at approximately Days 0, 56, and 112.
Safety will be measured from the time of each study vaccination (Days 0, 56, 112 [Visits 2, 7, 12]) through 7 days after each study vaccination by the occurrence of solicited injection site and systemic reactogenicity events. Unsolicited non-serious adverse events (AEs) will be collected from the time of each study vaccination through approximately 28 days after each study vaccination. New-onset chronic medical conditions (including adverse events of special interest [AESI]) and serious adverse events (SAEs) will be collected from the time of the first study vaccination (Day 0 [Visit 2]) through approximately 9 months after the third study vaccination (Day 380 [Visit 19]). Clinical laboratory evaluations for safety will be performed on venous blood collected approximately 7 days after each study vaccination.
Immunogenicity testing will include IgG antibody responses to Sm-TSP-2 by a qualified indirect ELISA on serum obtained prior to each study vaccination (Days 0, 56, 112) and at time points after each vaccination.
Ninety subjects will be enrolled into 3 groups of 30. Recruitment and enrollment into the study will occur on an ongoing basis, with each group being recruited and vaccinated in sequence.
Part A of the study is a dose escalation trial in which escalation to the next dose cohort will be determined based on evaluation of pre-defined escalation criteria, which will be evaluated 7 days after all subjects in the currently active cohort have received their first dose of vaccine. Within each cohort, the assignment to Alhydrogel®, Alhydrogel®/AP 10-701, or Hepatitis B vaccine will be randomized and double-blinded (i.e., neither the subject nor the investigator will be aware of the formulation assigned). The study will proceed as follows:
- Cohort 1, N=30 [10mcg Sm-TSP-2/Alhydrogel® (n=12) or 10mcg Sm-TSP-2/Alhydrogel®/ AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to the remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Make escalation decision
- Cohort 2, N=30 [30mcg Sm-TSP-2/Alhydrogel® (n=12) or 30mcg Sm-TSP-2/Alhydrogel®/AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to the remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Make escalation decision
- Cohort 3, N=30 [100mcg Sm-TSP-2/Alhydrogel® (n=12) or 100mcg Sm-TSP-2/Alhydrogel®/AP 10-701 (n=12) or Hepatitis B vaccine (n=6)]
- Enroll, randomize, and administer first dose of study vaccine or Hepatitis B vaccine to initial 6 subjects
- After initial 6 subjects have completed Visit 3, administer the first dose of study vaccine or Hepatitis B vaccine to remaining 24 subjects
- Assess 7 day post dose 1 safety data for all subjects
- Complete follow-up for all subjects
- Close the study
Part B: double blind, randomized, controlled, dose-escalation Phase IIb clinical trial in adults living in the area of Kampala, Uganda, who reside in S. mansoni endemic areas with greater than or equal to 25% prevalence in children aged 5-15 years of age. In this part of the study, up to 200 eligible Schistosoma-positive (by Kato Katz fecal thick smear or CAA) adult volunteers will be progressively enrolled and randomized to receive either Sm-TSP-2/Alhydrogel® (with or without AP 10-701) or the Hepatitis B comparator vaccine, in a 1:1 fashion. The dose and formulation (i.e., with or without the point-of-injection addition of AP 10-701) of Sm-TSP-2/Alhydrogel® that will be tested in this part of the study will be chosen based on the interim results of Part A of the trial after all participants have received their third dose of vaccine. All participants in Part B will be treated with praziquantel prior to receipt of the first vaccination.
Interim safety and anti-Sm-TSP-2 IgG antibody results up to and including Day 126 of Part A of the trial will be evaluated to determine the dose that will be tested in Part B.
Two hundred subjects will be enrolled in Part B. The 12 subjects in Part A who received the same dose/formulation of Sm-TSP-2/Alhydrogel® that is chosen for Part B will be offered the opportunity to transition to Part B for the remainder of their participation in the study.
Recruitment and enrollment into the study will occur on an ongoing basis, with participants being recruited, randomized and vaccinated in sequence. Within Part B, the assignment to Sm-TSP-2/Alhydrogel® or Hepatitis B vaccine will be randomized and double-blinded (i.e., neither the subject nor the investigator will be aware of the formulation assigned). Part B of the study will proceed as follows:
- Cohort 4, N=200 [Sm-TSP-2/Alhydrogel® [dose and formulation TBD] (n=100) or Hepatitis B vaccine (n=100)]
Subjects will receive three doses of the assigned vaccine delivered intramuscularly at approximately Days 0, 56, and 112.
Safety will be measured from the time of each study vaccination (Days 0, 56, 112 [Visits 2, 7, 12]) through 7 days after each study vaccination by the occurrence of solicited injection site and systemic reactogenicity events. Unsolicited non-serious adverse events (AEs) will be collected from the time of each study vaccination through approximately 28 days after each study vaccination. New-onset chronic medical conditions (including adverse events of special interest [AESI]) and serious adverse events (SAEs) will be collected from the time of the first study vaccination (Day 0 [Visit 2]) through approximately 23 months after the third study vaccination (Day 800 [Visit 21]). Clinical laboratory evaluations for safety will be performed on venous blood collected approximately 7 days after each study vaccination.
Immunogenicity testing will include IgG antibody responses to Sm-TSP-2 by a qualified indirect ELISA on serum obtained prior to each study vaccination (Days 0, 56, 112) and at time points after each vaccination.
Efficacy will be evaluated by measuring the impact of vaccination with Sm-TSP-2/Alhydrogel® on fecal and urine Schistosoma egg counts and CAA positivity. After final vaccination, fecal and urine samples will be collected at 12 and 23 months following the final vaccination to determine rates and intensities of re-infection. The primary endpoint to determine the impact of vaccination on infection with S. mansoni will be incidence of infection as determined by a positive CAA test or Kato-Katz fecal thick smear. The impact of vaccination on infection with S. haematobium will be assessed as an exploratory endpoint, by means of urine microscopy for schistosome eggs.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 9
| Arm | Type | Receives |
|---|---|---|
| Part A, Group A (Sm-TSP-2/Alhydrogel 10 mcg) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccineSm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 10 mcg dose |
| Part A, Group B (Sm-TSP-2/Alhydrogel 10 mcg + AP 10-701) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 10 mcg dose |
| Part A, Group C (Sm-TSP-2/Alhydrogel 30 mcg) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccineSm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 30 mcg dose |
| Part A, Group D (Sm-TSP-2/Alhydrogel 30 mcg + AP 10-701) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 30 mcg dose |
| Part A, Group E (Sm-TSP-2/Alhydrogel 100 mcg) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccineSm-TSP-2/Alhydrogel Schistosomiasis Vaccine, delivered by IM injection on study days 0, 56, and 12; 100 mcg dose |
| Part A, Group F (Sm-TSP-2/Alhydrogel 100 mcg + AP 10-701) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701Sm-TSP-2/Alhydrogel Schistosomiasis Vaccine plus AP 10-701, delivered by IM injection on study days 0, 56, and 12; 100 mcg dose |
| Part A, Group G (HBV) | Active comparator | Biological: ENGERIX-B Hepatitis B VaccineHepatitis B Vaccine |
| Part B, Group H (Sm-TSP-2/Alhydrogel +/- AP 10-701) | Experimental | Biological: Sm-TSP-2/Alhydrogel® vaccineSm-TSP-2/Alhydrogel Schistosomiasis Vaccine, with or without AP 10-701, dose and formulation determined in Part A |
| Part B, Group I (HBV) | Active comparator | Biological: ENGERIX-B Hepatitis B VaccineHepatitis B Vaccine |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (10 listed)
- Provide written informed consent prior to any study procedures.
- Able to understand and comply with planned study procedures and be available for all study visits.
- Male or non-pregnant female aged 18 to 45, inclusive at the time of enrollment.
- Are in good health, as determined by vital signs (oral temperature, pulse, and blood pressure), medical history, and brief physical examination at screening.
- Vital signs (oral temperature, pulse, and blood pressure) are all within normal protocol-defined ranges.
Key exclusion criteria (23 listed)
- Has the intention to become pregnant within 5 months after enrollment in this study.
- Female subjects who are breastfeeding or plan to breastfeed at any given time from the first study vaccination until 30 days after their last study vaccination.
- Has an acute illness, including a documented oral temperature of 38.0°C or greater, within 72 hours prior to vaccination.
- Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
- Is immunosuppressed as a result of an underlying illness or treatment.
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 |
|---|---|---|
| Sm-TSP-2/Alhydrogel® vaccineThe Sm-TSP-2/Alhydrogel® candidate vaccine contains recombinant Sm-TSP-2 adsorbed onto aluminum hydroxide gel (Alhydrogel®) and suspended in a solution containing 10mM imidazole buffer containing 2mM phosphate and 15% sucrose, with pH 7.4 ± 0.1. The final concentrations of Sm-TSP-2 and Alhydrogel® in the drug product are 0.1mg/ml and 0.8mg/ml respectively. | Biological | Part A, Group A (Sm-TSP-2/Alhydrogel 10 mcg), Part A, Group C (Sm-TSP-2/Alhydrogel 30 mcg), Part A, Group E (Sm-TSP-2/Alhydrogel 100 mcg), Part B, Group H (Sm-TSP-2/Alhydrogel +/- AP 10-701) |
| Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701The Sm-TSP-2/Alhydrogel® candidate vaccine co-administered with the immunostimulant, AP 10-701. b) AP 10-701, also known as Gluco-Pyranosylphospho-Lipid A Aqueous Formulation (GLA-AF), is a Toll-like Receptor-4 agonist. Point-of-injection formulations with this immunostimulant will be prepared immediately prior to vaccination by adding an appropriate volume of AP 10-701 to Sm-TSP-2/Alhydrogel® and withdrawing an appropriate volume to administer the desired amount of Sm-TSP-2 plus 5µg GLA-AF. | Biological | Part A, Group B (Sm-TSP-2/Alhydrogel 10 mcg + AP 10-701), Part A, Group D (Sm-TSP-2/Alhydrogel 30 mcg + AP 10-701), Part A, Group F (Sm-TSP-2/Alhydrogel 100 mcg + AP 10-701) |
| ENGERIX-B Hepatitis B VaccineRecombinant hepatitis B vaccine containing 10 mcg recombinant hepatitis B surface antigen per dose | Biological | Part A, Group G (HBV), Part B, Group I (HBV) |
Primary outcome
Safety and Tolerability: frequency of local and systemic reactogenicity events
Time frame: 7 days post-vaccination
Frequency of solicited injection site and systemic reactogenicity, graded by severity, on the day of each study vaccination through 7 days after each study vaccination.
Safety and Tolerability: frequency of unsolicited adverse events
Time frame: 28 days post-vaccination
Frequency of unsolicited adverse events, graded by severity, from the time of each study vaccination through approximately 1 month after each study vaccination.
Safety and Tolerability: frequency of vaccine-related Serious Adverse Events
Time frame: 23 months
Frequency of study vaccine-related Serious Adverse Events from the time of the first study vaccination through the final study visit.
Safety and Tolerability: frequency of clinical safety laboratory adverse events
Time frame: 7 days post-vaccination
Frequency of clinical safety laboratory adverse events measured 7 days after each vaccination
Safety and Tolerability: frequency of new-onset chronic medical conditions
Time frame: 23 months
Frequency of new-onset chronic medical conditions, including Adverse Events of Special Interest, through the final study visit
Efficacy: proportion of subjects with detectable S. mansoni eggs
Time frame: 12 and 23 months
Proportion of subjects with detectable S. mansoni eggs at 12 and 23 months in fecal samples, as determined by Kato Katz fecal thick smear.
Efficacy: mean S. mansoni eggs per gram of feces
Time frame: 12 and 23 months
Mean S. mansoni eggs per gram as determined by fecal microscopy (Kato Katz fecal thick smear) at 12 and 23 months.
Efficacy: Proportion of subjects with a positive CAA test
Time frame: 12 and 23 months
Proportion of subjects with a positive CAA test at 12 and 23 months.
2 secondary outcomes
Immunogenicity: peak anti-Sm-TSP-2 IgG level
Time frame: Day 126
Immunogenicity: anti-Sm-TSP-2 IgG levels over time
Time frame: Approximately 14 days after doses one and two and at Days 200, 290, 380 (Parts A and B) after final dose, and at Days 548, and 800 (Part B) after final dose.
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 4 Nov 2025.
- Individual participant dataSharing planned: Yes. De-identified individual participant data related to primary and secondary objectives will be made available within 12 months of finalization of the Clinical Study Report.
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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.
Hannah Kibuuka, MD principal investigator
Makerere University Walter Reed Project
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Sm-TSP-2/Alhydrogel® vaccine, Sm-TSP-2/Alhydrogel® vaccine plus AP 10-701 and ENGERIX-B Hepatitis B Vaccine in people with Schistosomiasis and Schistosoma Mansoni, run by Baylor College of Medicine at 1 site in Uganda.
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 10 inclusion and 23 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 4 Nov 2025. 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 Uganda. 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 combined 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.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Safety and Tolerability: frequency of local and systemic reactogenicity events (time frame: 7 days post-vaccination). The study lists 8 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 4 Nov 2025.