Article on news.com.au, page-24

An excerpt below talking about Gardasil studies to put things in perspective. Much bigger operation by the looks of things but similar looking results from early studies indicating dose dependant response.

Full story can be found here: http://www.fda.gov/ohrms/dockets/ac/06/briefing/2006-4222B3.pdf


Phase 1 and Phase 2 Studies

Merck conducted six phase 1 and phase 2 clinical studies between 1997 and 2004. Four smaller phase 1 or early phase 2 studies evaluated monovalent HPV VLP vaccines, serotypes 11, 16, or 18, in order to characterize safety and immune responses among different doses. Two larger phase 2 studies were conducted between 2000 and 2004 that included clinical endpoints in addition to the safety and immune response endpoints. The results of these studies were used to identify appropriate dose and endpoints to be used in the phase 3 pivotal studies. The studies suggested an acceptable safety profile for further clinical development. The larger phase 2 studies provided supportive evidence of vaccine activity. The applicant’s clinical development program focused on a three-dose regimen at months 0, 2, and 6 based on previous clinical and immunological experiences with their hepatitis B vaccine product.

Studies 001, 002, and 006 were small phase 1 safety studies that evaluated the monovalent HPV VLP serotypes 11, 16, and 18, respectively. Studies 001 and 002 enrolled 249 subjects, and approximately 200 received the vaccine. The results demonstrated a “dose response”, where higher doses generally resulted in larger post-vaccination geometric mean titers. Overall, the immune responses in subjects who received the 20 μg, 40 μg, or 50μg dose were better than the immune responses in subjects who received the 10 μg dose. There appeared to be no advantage in immune responses to an 80 μg dose, or to the administration of a fourth dose.