Studies of GARDASIL, Merck's Cervical Cancer Vaccine, and HPV 16 Vaccine Component of GARDASIL Presented at International Papillomavirus Conference
- Data from an Extension of a Phase II Study for an Average of 8.5 Years Evaluating the ongoing efficacy of HPV 16 Component of GARDASIL Presented
- Investigational Study with GARDASIL: Data Presented on Reduction in Abnormal Pap Tests and Cervical Procedures in Women Naïve to Multiple HPV types
MALMOE, Sweden, May 8, 2009 - In a study of an extended follow up of 290 women naïve to HPV type 16, the HPV 16 component of GARDASIL® [Human Papillomavirus Quadrivalent (Types 6, 11, 16, 18) Vaccine, Recombinant] was efficacious against HPV 16 infection for an average of 8.5 years after administration. The women enrolled in this study are a subset of the original Phase II HPV 16 proof-of-concept study published in 2002. Follow up ranged from 7.2 years to up to 9.5 years.
In a different study, in women ages 16 to 26 who were naïve to 14 common HPV types, GARDASIL reduced the number of abnormal Pap test results by 17 to 45 percent, depending on the abnormality, and reduced colposcopies by 20 percent, cervical biopsies by 22 percent and reduced surgery and other invasive treatments by 42 percent.
"We are encouraged by the extended efficacy data for the HPV 16 component of GARDASIL. Studies to examine the long-term efficacy of GARDASIL are underway," said Laura A. Koutsky, Ph.D., MSPH, University of Washington, School of Public Health. Dr. Koutsky and the University of Washington study site led this study extension. Merck & Co., Inc. is a co-author of the original data and the new analysis.
GARDASIL is currently indicated for use in girls and young women 9 through 26 years of age for the prevention of cervical, vulvar and vaginal cancers caused by HPV types 16 and 18; genital warts caused by HPV types 6 and 11; and precancerous or dysplastic lesions caused by HPV types 6, 11, 16 and 18.
HPV types 16 and 18 are responsible for approximately 70 percent of cervical cancer cases, and HPV types 6 and 11 are responsible for approximately 90 percent of genital warts and about 10 percent of low-grade cervical changes/lesions/dyplasias.
Efficacy of the prophylactic human papillomavirus (HPV) type 16 L1 virus-like particle (VLP) vaccine
In a follow-up study of 290 women from a randomized, placebo-controlled, proof-of-concept clinical trial, the HPV 16 component of GARDASIL remained efficacious against HPV 16 infection and associated precancerous lesions for an average follow-up time of 8.5 years after administration.
These women had participated in a Phase IIb randomized-controlled trial of the prophylactic HPV 16 L1 virus-like particle (VLP) vaccine between November 1998 and January 2004. They were enrolled in an extended follow-up study between March 2006 and May 2008 to evaluate the vaccine's long-term efficacy. Participants had not been infected with HPV 16 at the start of the study and through month seven (one month after the completion of the three-dose series).
During the extended follow-up period, no one in the vaccine group developed HPV 16 infection (vaccine efficacy = 100 percent; 95 percent confidence interval (CI): 25 to 100 percent) or HPV 16-associated cervical lesions (cervical intraepithelial neoplasia, or CIN) (vaccine efficacy = 100 percent; 95 percent CI: <0 to 100 percent). In the placebo group, six women developed HPV 16 infection and three women developed HPV 16-associated CIN during the follow-up period. Following participation in the initial study, all subjects were offered vaccination with GARDASIL. Only those subjects who chose not to be vaccinated and who explicitly consented to being part of the extension study were enrolled.
During the combined trial and extended follow-up period - mean of 8.5 years, vaccine efficacy against HPV 16 infection was 96 percent; (95 percent CI: 73 to 100 percent) and 100 percent against cervical lesions associated with HPV 16 (95 percent CI: 47 to 100 percent). In the placebo group, 21 women developed HPV 16 infection and eight women developed HPV 16-associated cervical lesions, including 7 cases of CIN 2 or worse.
In second investigational study, reduction in abnormal Pap tests and procedures
In two other randomized, placebo-controlled, efficacy trials of GARDASIL, a total of 17,622 women received either three doses of GARDASIL or placebo over six months. Pap testing occurred at the start of the study and then at intervals of 6 to 12 months. An analysis of the reduction of healthcare utilization endpoints (Pap tests and cervical procedures) was conducted in a population of women who were naive to 14 common HPV types and had a normal Pap test on day 1.
After an average follow-up of 3.6 years when compared to women receiving placebo (n=4679), women who received GARDASIL (n=4616) had significant reductions in the following abnormal Pap test results:
- ASC-US: atypical squamous cells of undetermined significance associated with a high-risk type of HPV (17 to 22 percent reduction),
- LSIL: low-grade squamous intraepithelial lesion (17 percent reduction),
- ASC-H: atypical squamous cells/cannot exclude high-grade squamous intraepithelial lesion (36 percent reduction), and
- HSIL: high-grade squamous intraepithelial lesion (45 percent reduction).
Additional important information about GARDASIL
GARDASIL is contraindicated in individuals with hypersensitivity, including severe allergic reactions to yeast, or after a previous dose of GARDASIL.
The health care provider should inform the patient, parent or guardian that vaccination does not substitute for routine cervical cancer screening. Women who receive GARDASIL should continue to undergo cervical cancer screening per standard of care.
GARDASIL is not recommended for use in pregnant women.
The duration of protection with GARDASIL is currently not known. Vaccination with GARDASIL may not result in protection in all vaccine recipients. GARDASIL is not intended to be used for treatment of active genital warts, cervical, vaginal and vulvar cancers, cervical intraepithelial neoplasia (CIN), vulvar intraepithelial neoplasia (VIN) or vaginal intraepithelial neoplasia (VaIN).
GARDASIL has not been demonstrated to provide protection against disease from vaccine and non-vaccine HPV types to which a woman has previously been exposed through sexual activity. GARDASIL has not been shown to protect against diseases due to HPV types not contained in the vaccine.
Not all vulvar and vaginal cancers are caused by human papillomavirus (HPV), and GARDASIL protects only against those vulvar and vaginal cancers caused by HPV types 16 and 18.
In clinical studies for GARDASIL, headache was the most commonly reported adverse reaction with near equal frequency in the GARDASIL and control group (28.2 percent vs. 28.4 percent). Vaccine-related adverse reactions that were observed at a frequency of at least 1.0 percent among recipients of GARDASIL and also greater than those observed among control group, respectively, were pain (83.9 percent vs. 75.4 percent), swelling (25.4 percent vs. 15.8 percent), erythema (24.7 percent vs. 18.4 percent), fever (13.0 percent vs. 11.2 percent), nausea (6.7 percent vs. 6.5 percent), pruritis (3.2 percent vs. 2.8 percent), dizziness (4.0 percent vs. 3.7 percent) and bruising (2.8 percent vs. 3.2 percent).
In addition, syncope has been reported following vaccination with GARDASIL, sometimes resulting in falling with injury. Observation for 15 minutes after administration is recommended.
Dosage and administration for GARDASIL
GARDASIL is a ready-to-use, three-dose, intramuscular vaccine. GARDASIL should be administered in three separate intramuscular injections in the deltoid region of the upper arm or in the higher anterolateral area of the thigh. The following dosage schedule is recommended: first dose at elected date, second dose two months after the first dose and the third dose six months after the first dose.
GARDASIL is approved in 109 countries
GARDASIL (sold in some countries as SILGARD®) has been approved in 109 countries, and additional applications are currently under review with regulatory agencies in many more countries around the world.
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