Clinical Development Of Bird Flu Vaccines For Pre-Pandemic Uses To Be Discussed By Cmte.
This article was originally published in The Pink Sheet Daily
Executive Summary
FDA’s Vaccines and Related Biological Products Advisory Committee will meet Feb. 27.
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FDA's Vaccines and Related Biological Products Advisory Committee will discuss approval standards for pandemic influenza vaccines for use in a pre-pandemic setting during a Feb. 27 meeting. "Given the multiple potential barriers to assuring maximum deployment of a pandemic influenza vaccine once human-to-human spread has been identified, alternate approaches are under consideration. One such strategy that we intend to discuss today is pre-pandemic vaccination," FDA's Office of Vaccine Research and Review states in briefing documents for the committee. The committee may be asked to comment on the "duration of immune responses and length of time necessary to demonstrate a desired 'boost' response to a homologous antigen or heterologous antigen" as well as the size of safety database required for a pre-pandemic claim, FDA says. The panel, which will convene in Gaithersburg, Md., will also discuss preliminary safety and effectiveness data for Sanofi Pasteur's pandemic flu vaccine. [Editor's note: To 1 watch a webcast or order a video/DVD of this meeting, visit FDAAdvisoryCommittee.com.] Sanofi has submitted a BLA for an H5N1A/Vietnam/1203/2004 avian influenza vaccine. Sanofi has a contract worth over $100 million with HHS to produce pandemic vaccine for the U.S. stockpile (2 (Also see "HHS Boosts Pandemic Flu Vaccine Stockpile With Contracts Totaling $200 Mil." - Pink Sheet, 20 Nov, 2006.)). The panel will review a randomized, double-blind, placebo-controlled study in healthy adults ages 18 to 64 years old. The Phase I/II trial, which was sponsored by NIH, evaluated safety, reactogenicity and immunogenicity of the investigational influenza A/H5N1 virus vaccine. The five-arm dose-ranging study included placebo and four doses ranging from 7.5 ug to 90 ug. The three primary endpoints were defined as: (1) proportion of subjects in each dose achieving a serum neutralizing antibody titer ratio of 1:40 against the influenza A/H5N1 virus 28 days following the second dose of the vaccine, and geometric mean titer and the frequency of 4-fold or greater increases in both; (2) neutralizing; and (3) HAI antibody titers in each group one month after receipt of each dose, and seven months after receipt of the first dose. Four weeks after the vaccination, the percentage of patients exhibiting a 4-fold rise in HAI titer was substantially higher for the 45 ug (22.4) and 90 ug (23.1) doses than the lower doses. Among study participants, there were no significant safety signals that would preclude administration of the vaccine to additional persons, FDA says. "Data from this study demonstrated that higher antigen doses and repeat dosing produced a higher antibody response. The need for larger amounts of antigen and for the administration of two doses approximately one month apart create supply and logistical concerns when preparing for administration of a vaccine to a large population at risk," the agency says. The first H5N1 virus known to infect humans occurred in Hong Kong in 1997, causing 18 cases and six deaths. The virus has sporadically infected humans primarily in Southeast Asia - 270 people total, in ten countries, with a death rate of 60.7 percent. -Jamie Hammon ([email protected]) |