Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02624349 |
| Other study ID # |
1000037024 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
Phase 4
|
| First received |
|
| Last updated |
|
| Start date |
October 2013 |
| Est. completion date |
December 2017 |
Study information
| Verified date |
February 2021 |
| Source |
The Hospital for Sick Children |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The human papilloma virus (HPV) is known to be an important cause of cervical and anal
cancers. Studies on patients who have received a solid organ transplant (such as a liver or
kidney transplant) have suggested the risk of HPV-related cancers may be higher in this
population. The HPV vaccine, Gardasil®, has been approved for use in males and females by
Health Canada. In studies on healthy subjects this vaccine is nearly 100% effective at
preventing infections from HPV serotypes that are in the vaccine. These serotypes,
representing different viral strains, are known to cause 70% of cervical cancers and 90% of
genital warts. The vaccine was also shown to be very safe and well tolerated in healthy
subjects. Transplant patients are at higher risk of HPV related complications and cancers. As
a result transplant experts have recommended this vaccine for use in their patients; however
there have been no studies looking at the response to vaccination or safety of this vaccine
in solid organ transplant recipients. Our objective is to study the immune response and side
effects of Gardasil® in children who have received kidney or liver transplants. We will study
this by comparing immune responses to the vaccine in healthy adolescent females compared to
female liver and kidney transplant recipients. We will be recruiting females ages 12-19, as
the province of Ontario funds the vaccine for this group. We will evaluate the transplant
subjects for side effects after they receive the vaccine. Our hypothesis is that transplant
recipients will have lower immunogenicity than healthy controls.
Description:
1. Hypothesis The Human papillomavirus (HPV) vaccine, Gardasil®, will likely provide
protection in solid organ transplant patients against the vaccinated strains with lower
immunogenicity rates compared to healthy controls. We expect higher levels of immune
suppression to influence immunogenic response.
2. Objective Primary: To evaluate the immunogenicity of the recombinant HPV vaccine,
Gardasil®, in pediatric solid organ transplant recipients compared to controls, as well
evaluate for clinical risk factors associated with lower responses in transplant
recipients. Immunogenicity will be assessed through geometric mean titres (GMT) as well
as seroconversion.
Secondary: To evaluate the safety of Gardasil® in transplant recipients.
3. Background
3.1 Disease HPV is known to predispose to cervical, anal, and a variety of head and neck
cancers in both healthy adults and in those who are immunocompromised, including those
who have received solid organ transplants. An estimated 3 million women in Canada are
infected with HPV. Peak incidence occurs within 5-10 years of first sexual experience
and adolescent females represent the largest cohort affected by HPV.
3.2 Vaccine In 2006 the Food and Drug Administration approved the quadravalent
recombinant HPV vaccine, Gardasil®, which targets strains 16 and 18 as well as 6 and 11,
which are responsible for 70% of cervical cancer cases and 90% of genital warts,
respectively. Health Canada has recently approved Gardasil® for use in females' aged
9-45 years and males 9-26 years. Gardasil® has been shown in numerous clinical trials to
be effective in the management of HPV by preventing vaccine sub-type related infections
and precancerous lesions. Gardasil® is regarded as generally safe and well tolerated
based on reported adverse events through government databases in the United States, as
well as analyses by independent researches. The bivalent HPV vaccine, Cervarix®, also
appears safe and effective in preventing cervical cancer, however the data are less
robust and there would be no protection against genital wart strains. Long term benefits
of HPV vaccination are unknown, however models have predicted both a significant
mortality benefit by preventing cases of cervical cancer7 and overall
cost-effectiveness; particularly if the vaccine is administered to girls under the age
of twelve.
3.3 HPV in Transplant Patients Due to the prominent role of cell-mediated immunity in
HPV, transplant recipients are felt to be at increased risk of infection leading to
extensive or frequent warts, and increased incidence of skin and anogenital
malignancies. Skin cancers are the most common malignancy affecting patients post
transplantation. Anogenital cancer incidence is estimated to be 30-100 times greater in
transplant patients compared to the general population. HPV is a preventable cause of a
large number of these malignancies, suggesting that a vaccine could potentially thwart
some of the morbidity and mortality experienced by transplant recipients. Furthermore,
studies have suggested that organ transplant patients are more likely to be infected
with HPV as well as develop secondary neoplasias. For these reasons vaccinating this
population against HPV has the potential for significant long-term benefits.
4. Methods 4.1 Design We are proposing a prospective observational study by evaluating the
serological response for the vaccine covered HPV serotypes; 6, 11, 16, and 18. This
study will take advantage of routine, provincially funded population based vaccination
program, and patients will receive the vaccine in the study that healthy adolescents
receive at school in grades 7 or 8. Study subjects will be identified using the liver
and kidney transplant clinical database and control subjects will be identified through
the Hospital for Sick Children adolescent medicine clinic. A letter of introduction will
be sent to the families. Consent will be obtained by the transplant nurse or physician
known to the patient. Transplant subjects will undergo baseline and post-immunization
serology to evaluate both GMT as well as to document seroconversion response to the
vaccine. Gardasil® will be funded through the province of Ontario. Controls will receive
their vaccine through the adolescent clinic, schools, or Toronto Public Health clinics
in the community as per the recommended schedule. At recruitment attempt will be made to
draw baseline serology status, vaccinate, and then collect post-immunization serology to
document seroconversion. However, to facilitate recruitment for controls that have
documented receipt of three doses of the vaccine these children will be recruited for
post-vaccination serology only to compare GMTs. Control vaccines will also be funded by
the province of Ontario and administered in accordance with Health Canada standards.
4.2 Investigational Agent
4.2.1 Vaccine storage and characteristics Gardasil® (Merck Canada Inc), the Quadravalent
Human papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine, was selected for this study
for its efficacy and safety data in healthy subjects, being publically funded by the province
of Ontario, and it provides protection for 4 HPV serotypes. Gardasil® should be stored
refrigerated 2-8 degrees Celsius, should not be frozen and remain protected from light. The
total time outside of refrigerator should not to exceed 72 hours. Vaccines will be stored
compliant with the division 5 Canadian regulations.
4.2.2 Administration of vaccine Gardasil® vaccine is recommended to be administered
intramuscularly in deltoid or thigh at a dose of 0.5ml at 0, 2, and 6 months. While every
effort will be made to keep the aforementioned schedule, studies support some flexibility in
the schedule. The 2nd dose will be administered at least 1 month after the 1st, but not more
than 9 months. The 3rd dose can be administered 3 months following the second dose, but not
more than 1 year following the first dose. All 3 doses must be administered within a 1 year
period to be included in analysis. Subjects will be monitored for 15 min post-vaccination for
any adverse effects.
4.3 Sample Size The study will be powered based on GMT immunogenicity. Based on this primary
outcome, we wish to compare serum titres in transplant patients compared with controls. The
sample size calculation is based on 90% power and 95% confidence and the assumption that a
HPV vaccination will result in protective titres in 80% of transplant patients compared to
100% of controls. A sample size of approximately 75 transplant recipients and 75 controls
will therefore be preferred to detect a significant difference, however recruitment of at
least 50 participants in each group is acceptable. Recruitment will take place over a 6 month
period, resulting in a total study duration of approximately 12 months, up to a maximum of 18
months accounting for possible delays in vaccine administration up to 1 year from end of
recruitment.
4.4. Analysis In the primary analysis of immunogenicity, the GMTs will be summarized for
transplant recipients and compared with controls. The proportions of subjects achieving
protective GMTs, as defined previously, will be compared using Chi-square or Fishers' exact
test as appropriate. Means will be compared using Students t-test or a non-parametric
procedure will be used to compare medians, as appropriate. Subjects and controls will be
evaluated as a head-to-head comparison. For controls serology will be interpreted relative to
time from last dose given. The investigators will use a multivariate analytic procedure to
examine the effects of several independent variables with immunogenicity as the dependent
variable. These independent variables are ones that could be potentially associated with
differences in immune responsiveness (e.g., the interval between transplantation and vaccine
administration). Other variables include the following: age; type of organ transplanted;
presence or absence of graft rejection; type of immune suppression (e.g., use of anti-T
lymphocyte therapy); immune globulin therapy; cytomegalovirus infection and disease;
Epstein-Barr virus infection and disease; presence of bacterial opportunistic infections,
concurrent diseases, steroid doses, and total lymphocyte count.
The secondary analysis will capture and describe the adverse effects among transplant
recipients through telephone calls at 48 hours and 7 days utilizing the Public Health Ontario
adverse event reporting form
4.5 Data Safety Monitoring Board and Research Ethics The study will be done with the approval
of the institution's Research Ethics Board. In addition, although we have no reasons to
anticipate problems with this vaccines in transplant patients, we will establish a Data
Safety Monitoring Board that will review emerging data that relate to any major or
catastrophic events that are temporally associated with the vaccine (even in the absence of
obvious causality).
4.5.1 Early Termination or Withdrawal Subjects and/or parents/legal guardians have the right
to withdraw from the study at any time for any reason. The investigator also has the right to
withdraw subjects from the study if it is in the best interest of the subject.
Subject withdrawal criteria are as follows:
- Withdrawal of informed consent (subject's decision to withdraw for any reason)
- Serious adverse event which, in the opinion of the investigator, indicates that
continued participation in the study is not in the best interest of the subject
- Any clinical adverse event or inter-current illness which, in the opinion of the
investigator, indicates that continued participation in the study is not in the best
interest of the subject (ex. Participants who develop symptoms of hypersensitivity after
receiving the first or second dose of Gardasil® will be withdrawn from the study and
will not receive further doses of Gardasil®)
- Pregnancy
- Subject non-adherence with the vaccine administration schedule defined above In the
event a subject is withdrawn due to an Adverse Event, this will be recorded and subjects
will continue to be followed until these events are resolved or stabilized, if possible.
4.5.2 Adverse Events All adverse events will be reported to the Hospital for Sick Children
Research Ethics Board according to the Hospital for Sick Children's adverse event reporting
requirements. All serious, unexpected adverse drug reactions to the study medication will be
reported to Health Canada within 15 calendar days or for death or life-threatening events,
within 7 calendar days. In the latter case, a follow-up report must be filed within 8
additional calendar days. Adverse reactions will be managed according to the Hospital for
Sick Children's standard clinical management practices.
