Safety and Immunogenicity Study of Trivalent P2-VP8 Subunit Rotavirus Vaccine in Adults, Toddlers and Infants

Phase 1

Completed

Conditions: Healthy

Interventions: Biological: Placebo
Biological: Trivalent P2-VP8 Subunit Rotavirus Vaccine

Registration Number: NCT02646891

Lead Sponsor: PATH

Brief Summary: This is is a study of a parenteral trivalent rotavirus vaccine (P2-VP8 subunit rotavirus vaccine). The study examined the safety and immunogenicity of three dose levels of this vaccine in healthy South African adults, toddlers and infants. Progression from one dose level to another and to the next age group population was based on the assessment of safety information from the lowest dose and older age group.

The primary safety hypothesis is that the P2-VP8 subunit rotavirus vaccine is safe and well-tolerated. The primary immunogenicity hypothesis is that the trivalent P2-VP8 subunit rotavirus vaccine is immunogenic in infant participants and will induce an immune response to at least 2 of the 3 strains in 60% or more of participants in at least one of the study groups.

Detailed Description: The P2-VP8 vaccine tested in this study was developed by Dr. Taka Hoshino at National Institute of Allergy and Infectious Diseases (NIAID). The monovalent (P\[8\]) vaccine previously tested consisted of bacteria-expressed VP8 subunit from the Wa strain of human rotaviruses (G1\[P8\]). A deoxyribonucleic acid (DNA) segment encoding the sequence of P2 epitope from tetanus toxin was fused to the VP8 sequence, resulting in this chimeric protein vaccine (P2-VP8). Dr. Hoshino's laboratory demonstrated in preclinical testing that the immunogenicity of these VP8 proteins could be significantly enhanced when fused with the P2 epitope of tetanus toxin, which exerts a strong T cell helper function. Further, immunization of neonatal piglets with a P2-VP8-P\[8\] chimeric protein conferred significant protection against experimental rotavirus gastroenteritis. Based on results of the initial first-in-human testing of the monovalent (P\[8\]) vaccine, a trivalent vaccine that includes antigens from P\[4\], P\[6\] and P\[8\] strains (DS-1, 1076 and Wa, respectively) has been developed to broaden responses for these 3 P-types, which together are responsible for the vast majority of global disease burden. The trivalent vaccine was assessed in this study.

The first clinical testing of the monovalent (P\[8\]) P2-VP8 subunit rotavirus vaccine was performed in 18-45 year old adults in North America. Overall, the vaccine was well-tolerated at all three dose levels, was associated with only mild transient local reactogenicity, and no safety concerns were identified. Almost all vaccine recipients demonstrated greater than 4-fold rise in IgG and IgA response to P2-VP8 antigen by enzyme-linked immunosorbent assay (ELISA) after three vaccinations: only one vaccine recipient did not demonstrate an immunoglobulin G (IgG) response (in the 30 µg group) and all vaccine recipients demonstrated immunoglobulin A (IgA) responses. Neutralizing antibody responses were also encouraging, with clear increases in geometric mean titers (GMTs) for all three dose levels at one month post-third study injection (Day 84) compared to pre-vaccination levels. Neutralizing antibody responses to heterologous rotavirus strains were most robust to P\[8\] strains, moderate to the P\[4\] strain and fairly limited to the P\[6\] strain.

Clinical testing of the monovalent (P\[8\]) P2-VP8 subunit rotavirus vaccine was initiated in South African toddlers and infants in 2014. The vaccine was generally well-tolerated at all three dose levels. In both toddlers and infants, when local reactogenicity was reported, it was transient, rarely greater than mild, and never severe. When present, systemic reactogenicity was also transient and generally mild, without discernable dose effect. In the dose-escalation phase of the testing in the infant cohorts, the study injections were paused temporarily due to findings of severe neutropenia on post-vaccination laboratory monitoring in three participants (two infants and one toddler) but were later resumed after the Safety Review Committee assessed that the data did not support relation to the study vaccine. The primary serology results in the infant cohorts were close to universal responses, with substantial increases in titer as demonstrated by mean-fold increase in GMT. In infants receiving the 30 µg dose, the GMT rose from a baseline value of 107 to a post-vaccination value of 9,583. Although not as dramatic as the IgG responses, there were good IgA responses to P2-VP8, with the seroresponse rate over 80% in infants receiving 30 µg of vaccine. The 60 µg dose did not appear to provide any better response than the 30 µg dose, although this study was not powered for that comparison.

In summary, the P2-VP8 monovalent vaccine was generally well-tolerated in healthy South African infants, and there was no evidence that the higher vaccine dose (60 µg) provided any benefit in serologic responses or impact on shedding of Rotarix compared to the lower dose (30 µg).

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 618

Inclusion Criteria

Healthy adults (≥ 18 and ≤ 45 years), toddlers (≥ 2 and ≤ 3 years), and infants (≥ 6 and ≤ 8 weeks)
Participants will remain in the area during the study
Females of childbearing potential must not be pregnant or breastfeeding, and willing to use adequate method of contraception during the trial.

Exclusion Criteria

Presence of fever or other acute illness
concurrent participation in another clinical trial
Presence of malnutrition or other systemic disorder.
Infants with history of premature birth (< 37 week gestational age)
History of congenital abdominal disorders or surgery
Suspected or known impairment of immune function
Infants who have received rotavirus vaccine in the past
Known sensitivity to any components of the vaccine
History of anaphylactic reaction
Major congenital or genetic defect
Unwillingness to follow study schedule
Receipt of immunoglobulin therapy or blood products in last 6 months
History of chronic immunosuppressive medications (with the exception of inhaled or topical steroids)
Any medical condition that, in the judgement of the investigator, would interfere with the protocol, or would interfere with participant's ability to adhere to the study protocol.
Clinically significant screening laboratory value
Human immunodeficiency virus (HIV) infection

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Adults: Placebo	Placebo	Adults received three intramuscular injections of placebo four weeks apart on Days 0, 28, and 56.
Toddlers: 90 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Toddlers received one intramuscular injection of 90 µg trivalent P2-VP8 subunit rotavirus vaccine on Day 0.
Infants: Placebo	Placebo	Infants received three intramuscular injections of placebo four weeks apart on Days 0, 28, and 56.
Infants: 30 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Infants received three intramuscular injections of 30 µg trivalent P2-VP8 subunit rotavirus vaccine four weeks apart on Days 0, 28, and 56.
Adults: 30 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Adults received three intramuscular injections of 30 µg trivalent P2-VP8 subunit rotavirus vaccine four weeks apart on Days 0, 28, and 56.
Infants: 15 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Infants received three intramuscular injections of 15 µg trivalent P2-VP8 subunit rotavirus vaccine four weeks apart on Days 0, 28, and 56.
Adults: 90 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Adults received three intramuscular injections of 90 µg trivalent P2-VP8 subunit rotavirus vaccine four weeks apart on Days 0, 28, and 56.
Toddlers: Placebo	Placebo	Toddlers received one intramuscular injection of placebo on Day 0.
Toddlers: 30 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Toddlers received one intramuscular injection of 30 µg trivalent P2-VP8 subunit rotavirus vaccine on Day 0.
Infants: 90 µg P2-VP8	Trivalent P2-VP8 Subunit Rotavirus Vaccine	Infants received three intramuscular injections of 90 µg trivalent P2-VP8 subunit rotavirus vaccine four weeks apart on Days 0, 28, and 56.

Primary Outcome Measures

Name	Time	Method
Number of Participants Experiencing Adverse Events (AE) Within 28 Days of Any Vaccination	Up to 28 days after any vaccination (up to Day 28 for toddlers and up to Day 84 for infants and adults)	Any symptom starting after 7 days post any study injection was recorded as an adverse event. A serious adverse event (SAE) is any event that occurred from the first dose of study drug that resulted in any of the following outcomes: 1. Death 2. Life-threatening AE 3. Inpatient hospitalization or prolongation of existing hospitalization 4. Persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions 5. Congenital abnormality or birth defect 6. Important medical event that may not result in one of the above outcomes but may jeopardize the health of the study participant or require medical or surgical intervention to prevent one of the outcomes listed above. The severity of adverse events was graded from Mild (grade 1) to Life Threatening (grade 4). AEs related to study drug were those events for which there was a reasonable possibility that the study drug caused the event In the opinion of the site investigator.
Number of Participants With Local or Systemic Reactions Within 7 Day of Vaccination	7 days following each vaccination	Reactogenicity data (solicited signs or symptoms) were assessed for 7 days after each injection. Participants and parents were instructed to assess and record daily local reactions (injection site pain/tenderness, redness, swelling, itching), as well as systemic signs and symptoms (fever, headache, vomiting, nausea, fatigue, chills and myalgia for adults; and fever, vomiting, decreased appetite, irritability, and decreased activity for toddlers and infants) in a participant memory aid. Reactions were graded on a scale from mild (Grade 1) to life-threatening (Grade 4). The overall number of participants who experienced any local or systemic reaction is reported. Grades are based on maximum severity per participant.
Number of Infants With Anti-P2-VP8 Immunoglobulin G (IgG) Seroresponse 4 Weeks After the Third Vaccination, by Vaccine Antigen	Day 84	Seroresponse was defined as a four-fold rise or greater in antibody titer between Baseline and 28 days after the third injection (Day 84). Measured by enzyme-linked immunosorbent assay (ELISA) and adjusted for decay in maternal IgG antibodies. The estimated maternal antibody half-life was derived from linear regression of Log2 transformed titers in placebo recipients from the combined infant cohorts.
Number of Infants With Anti-P2-VP8 Immunoglobulin A (IgA) Seroresponse 4 Weeks After the Third Vaccination, by Vaccine Antigen	Day 84	Seroresponse was defined as a four-fold rise or greater in antibody titer between Baseline and 28 days after the final injection (Day 84). Measured by enzyme-linked immunosorbent assay (ELISA) to whole viral lysate.
Number of Infants With Neutralizing Antibody Responses 4 Weeks After the Third Vaccination to Each Rotavirus Strain	Day 84	Neutralizing antibody response was defined as a ≥ 2.7-fold rise in antibody titer between Baseline and 28 days after the final injection (Day 84). Neutralizing antibodies to each of the three rotavirus strains from which the vaccine antigens were derived (Wa, DS-1, and 1076) were measured using a validated assay. For infants, antibody titer was adjusted for decay in maternal antibodies.
Anti-P2-VP8 Immunoglobulin G (IgG) Geometric Mean Titers Among Infants, by Vaccine Antigen	Baseline and Days 56 (pre-vaccination) and 84	Measured by ELISA at Baseline, 28 days after the second injection (Day 56 pre-vaccination; secondary outcome) and 28 days after the third and final injection (Day 84; primary outcome).
Anti-P2-VP8 Immunoglobulin A (IgA) Geometric Mean Titers Among Infants, by Vaccine Antigen	Baseline and Days 56 (pre-vaccination) and 84	Measured by ELISA at Baseline, 28 days after the second injection (Day 56 pre-vaccination; secondary outcome) and 28 days after the third and final injection (Day 84; primary outcome).
Geometric Mean Titers of Neutralizing Antibody Against Rotavirus Strains Among Infants	Baseline and Days 56 (pre-vaccination) and 84	Neutralizing antibodies to each of the three rotavirus strains from which the vaccine antigens were derived (Wa, DS-1, and 1076) were measured at Baseline and 28 days after the second injection (Day 56 pre-vaccination; secondary outcome) and third injection (Day 84; primary outcome).

Secondary Outcome Measures

Name	Time	Method
Number of Participants Experiencing Adverse Events (AE) Over the Entire Study Period	Up to 6 months after the last injection (224 days for adults and infants; 168 days for toddlers)	Any symptom starting after 7 days post any study injection was recorded as an adverse event. A serious adverse event (SAE) is any event that occurred from the first dose of study drug that resulted in any of the following outcomes: * Death - Life-threatening AE * Inpatient hospitalization or prolongation of existing hospitalization * Persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions * Congenital abnormality or birth defect * Important medical event that may not result in one of the above outcomes but may jeopardize the health of the study participant or require medical or surgical intervention to prevent one of the outcomes listed in the above definition of serious event. AEs related to study drug were those events for which there was a reasonable possibility that the study drug caused the event In the opinion of the site investigator.
Number of Infants With Anti-P2-VP8 Immunoglobulin G (IgG) Seroresponse 4 Weeks After the Second Vaccination, by Vaccine Antigen	Day 56, pre-vaccination	Seroresponse was defined as a four-fold rise or greater in antibody titer between Baseline and 28 days after the 2nd injection (Day 56). Measured by enzyme-linked immunosorbent assay (ELISA) and adjusted for decay in maternal antibodies. The estimated maternal antibody half-life was derived from linear regression of Log2 transformed titers in placebo recipients from the combined infant cohorts.
Number of Infants With Anti-P2-VP8 Immunoglobulin A (IgA) Seroresponse 4 Weeks After the Second Vaccination, by Vaccine Antigen	Day 56, pre-vaccination	Seroresponse was defined as a four-fold rise or greater in antibody titer between Baseline and 28 days after the second injection (Day 56). Measured by enzyme-linked immunosorbent assay (ELISA) to whole viral lysate.
Number of Infants With Neutralizing Antibody Responses 4 Weeks After the Second Vaccination	Day 56, prevaccination	Neutralizing antibody response was defined as a ≥ 2.7-fold rise in antibody titer between Baseline and 28 days after the second injection (Day 56). Neutralizing antibodies to each of the three rotavirus strains from which the vaccine antigens were derived (Wa, DS-1, and 1076) were measured using a validated assay. For infants, antibody titers were adjusted for decay in maternal antibodies.
Number of Adults and Toddlers With Anti-P2-VP8 Immunoglobulin G (IgG) Seroresponse, by Vaccine Antigen	Day 84 for adults; Day 28 for toddlers	Seroresponse was defined as a four-fold rise or greater in IgG antibody titer between Baseline and 28 days after the final injection (Day 84 for adults and Day 28 for toddlers). Measured by enzyme-linked immunosorbent assay (ELISA).
Number of Adults and Toddlers With Anti-P2-VP8 Immunoglobulin A (IgA) Seroresponse, by Vaccine Antigen	Day 84 for adults; Day 28 for toddlers	Seroresponse was defined as a four-fold rise or greater in IgA antibody titer between Baseline and 28 days after the final injection (Day 84 for adults and Day 28 for toddlers). Measured by enzyme-linked immunosorbent assay (ELISA).
Number of Adults and Toddlers With Neutralizing Antibody Responses to Each Rotavirus Strain	Day 84 for adults; Day 28 for toddlers	Neutralizing antibody response was defined as a ≥ 2.7-fold rise in antibody titer between Baseline and 28 days after the final injection (Day 84 for adults and Day 28 for toddlers) for each of the three rotavirus strains from which the vaccine antigens were derived (Wa, DS-1, and 1076).
Anti-P2-VP8 Immunoglobulin G (IgG) Geometric Mean Titers Among Adults and Toddlers, by Vaccine Antigen	Baseline and Day 28 for toddlers or Day 84 for adults	Measured at Baseline and 28 days after the final injection (Day 84 for adults; Day 28 for toddlers).
Anti-P2-VP8 Immunoglobulin A (IgA) Geometric Mean Titers Among Adults and Toddlers, by Vaccine Antigen	Baseline and Day 28 for toddlers or Day 84 for adults	Measured at Baseline and 28 days after the final injection (Day 84 for adults; Day 28 for toddlers).
Geometric Mean Titers of Neutralizing Antibody Against Rotavirus Strains Among Adults and Toddlers	Baseline and Day 28 for toddlers or Day 84 for adults	Measured at Baseline and 28 days after the final injection (Day 84 for adults; Day 28 for toddlers).

Trial Locations

Locations (3): Respiratory and Meningeal Pathogens Research Unit (RMPRU)
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Johannesburg, Gauteng, South Africa
Shandukani Research Centre
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Johannesburg, South Africa
Family Clinical Research Unit (FAM-CRU) Stellenbosch Univ
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Stellenbosch, South Africa