Phase I/II Double-blind, Randomized, Placebo-controlled, Descending Age, Dose-escalation Study of the Safety, and Immunogenicity of the Trivalent P2-VP8 Subunit Rotavirus Vaccine in Healthy South African Adults, Toddlers and Infants
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 发起方
- 入组人数
- 618
- 试验地点
- 6
- 主要终点
- Number of Participants Experiencing Adverse Events (AE) Within 28 Days of Any Vaccination
研究概览
简要总结
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.
详细描述
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).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 6 Weeks 至 45 Years（Child, Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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
结局指标
主要结局
Number of Participants Experiencing Adverse Events (AE) Within 28 Days of Any Vaccination
时间窗: 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
时间窗: 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
时间窗: 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
时间窗: 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
时间窗: 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
时间窗: 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
时间窗: 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
时间窗: 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).
次要结局
- 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))
- Number of Infants With Anti-P2-VP8 Immunoglobulin G (IgG) Seroresponse 4 Weeks After the Second Vaccination, by Vaccine Antigen(Day 56, pre-vaccination)
- Number of Infants With Anti-P2-VP8 Immunoglobulin A (IgA) Seroresponse 4 Weeks After the Second Vaccination, by Vaccine Antigen(Day 56, pre-vaccination)
- Number of Infants With Neutralizing Antibody Responses 4 Weeks After the Second Vaccination(Day 56, prevaccination)
- Number of Adults and Toddlers With Anti-P2-VP8 Immunoglobulin G (IgG) Seroresponse, by Vaccine Antigen(Day 84 for adults; Day 28 for toddlers)
- Number of Adults and Toddlers With Anti-P2-VP8 Immunoglobulin A (IgA) Seroresponse, by Vaccine Antigen(Day 84 for adults; Day 28 for toddlers)
- Number of Adults and Toddlers With Neutralizing Antibody Responses to Each Rotavirus Strain(Day 84 for adults; Day 28 for toddlers)
- 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)
- 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)
- Geometric Mean Titers of Neutralizing Antibody Against Rotavirus Strains Among Adults and Toddlers(Baseline and Day 28 for toddlers or Day 84 for adults)