Two dose Q-HPV Vaccine Study Simon Dobson BC Children’s Hospital Vaccine Evaluation Centre Child & Family Research Institute Vancouver University of British Columbia, Canada
Disclosures I have carried out vaccine clinical trials for: Merck GlaxoSmithkline Novartis Sanofi Pasteur Dynavax I have been on Advisory Boards for GlaxoSmithkline and Merck I have been on the National Advisory Committee on Immunization (Canada)
Why do this study? Cervical cancer is second most common cancer in women worldwide (500,000 per year) HPV vaccines offer the opportunity of primary prevention Barriers are vaccine cost and accessibility
Why do this study? Pre-licensure studies showed that 9-13 year olds responded better to the vaccine than 16-26 year olds Would it be possible to use this better response as an opportunity to use two instead of three doses?
Study Funded by: British Columbia Ministry of Health The Provincial Governments of Quebec and Nova Scotia
Control arms, Gardasil™ Trial design 2 dose versus 3 dose HPV vaccine study: a phase III post licensure randomized controlled trial Sample Size N=825 Study group 1 9-13 year olds females N=260 Study group 2 9-13 year old females N=260 Study group 3 16-26 year olds females N=305 Blinded outcome assessment Study arm, Gardasil™ 0 and 6 months Control arms, Gardasil™ 0, 2 and 6 months Primary outcome: Anti-HPV 16 and 18 GMT, t = 7 months 6 6
Primary Endpoints Differences in Geometric Mean Titres (GMT) of antibodies to HPV 16 and HPV 18 at Month 7 Non-inferiority will be declared if lower bounds of the adjusted 95% CI of GMT ratios for HPV 16 and HPV 18 are greater than 0.5 Take GMT of intervention group and compare to reference group (959 mMU/L divided by 575 mMU/L = 1.67 with a 95% CI of 1.46-1.91. Lower end of the 95% CI was greater than 0,5 (1.46) therefore the intervention arm is deemed to be non-inferior 7
Geometric Mean Titres in the Intention To Treat Population Dobson S et al. JAMA 2013
GMT Ratios in the Intention To Treat Population Dobson s et al. JAMA 2013
Conclusions Following a 2 dose regimen in 9-13 year old girls, antibody responses to HPV-16,-18,-6,-11 were non-inferior through 36 months, as compared to a 3-dose regimen in young adult women
GMT Ratios in the Intention To Treat Population Dobson s et al. JAMA 2013
Why is this important? Better use of resources Protects more girls Worldwide, saves lives
But….. Still need answers to two questions: What is the duration of protection? This is known for neither 3 doses nor 2 doses…yet Does 2 doses work as well as 3 doses? A Canadian study has started Extended 2 + 1 schedules are also possible