2011-20367. The Development and Evaluation of Next-Generation Smallpox Vaccines; Public Workshop

AGENCY:

Food and Drug Administration, HHS.

ACTION:

Notice of public workshop.

The Food and Drug Administration (FDA) Center for Biologics Evaluation and Research (CBER) and the National Institutes of Health, the National Institute of Allergy and Infectious Diseases are announcing a public workshop entitled “The Development and Evaluation of Next-Generation Smallpox Vaccines.” The purpose of the public workshop is to identify and discuss the key issues related to the development and evaluation of next-generation smallpox vaccines. The public workshop will include presentations on the human response to smallpox vaccines and development of animal models for demonstration of effectiveness of next-generation smallpox vaccines.

Date and Time: The public workshop will be held on September 16, 2011, from 8 a.m. to 5:30 p.m.

Location: The public workshop will be held at the Hilton Washington DC North/Gaithersburg, 620 Perry Pkwy., Gaithersburg, MD 20877.

Contact Person: Bernadette Williamson-Taylor, Center for Biologics Evaluation and Research (HFM-43), Food and Drug Administration, 1401 Rockville Pike, suite 200N, Rockville, MD 20852-1448, 301-827-2000, Fax: [phone], e-mail: [e-mail] (in the subject line type “Smallpox Workshop”).

Registration: Mail, fax, or email your registration information (including name, title, firm name, address, telephone, and fax numbers) to the contact person by August 23, 2011. There is no registration fee for the public workshop. Early registration is recommended because seating is limited. Registration on the day of the public workshop will be provided on a space available basis beginning at 7:30 a.m.

If you need special accommodations due to a disability, please contact Bernadette Williamson-Taylor (see Contact Person) at least 7 days in advance.

SUPPLEMENTARY INFORMATION:

Smallpox is a serious, highly contagious, and sometimes fatal infectious disease. Although the World Health Organization declared the disease eradicated in 1980, the threat of smallpox as a biological weapon remains. Vaccination is the only prevention for the disease and there are currently no FDA-approved treatments.

First-generation smallpox vaccines were prepared on the skin of calves or other animals or in chicken eggs. Although these vaccines were not evaluated for efficacy in well-controlled trials, they were highly effective as evidenced by the successful global eradication of smallpox. Manufacturing of these vaccines has ceased and they are no longer licensed in the United States.

In 2007, FDA licensed the first second-generation smallpox vaccine, ACAM2000. This vaccine is based on a single plaque-purified vaccinia virus derivative of Dryvax (a previously licensed first-generation vaccine) and is aseptically propagated using cell culture technology under modern manufacturing practices and standards. Both ACAM2000 and Dryvax are derived from the New York City Board of Health strain and produce a vesicular or pustular lesion (referred to as a “vaccine take”) that has been shown to correlate with protection. In clinical trials, ACAM2000 elicited vaccinia-neutralizing antibodies and cell-mediated immune responses, with both clinical and immunological outcomes similar to Dryvax.

Because ACAM2000 may cause serious adverse reactions, there is a desire to develop safer vaccines should there be a need to vaccinate the general population due to a threat of an attack with the smallpox virus. Currently, the next-generation smallpox vaccines under development do not produce the characteristic “vaccine take.” In addition, it is not ethical or feasible to evaluate the effectiveness of these vaccines in humans as the natural disease has been eradicated. Therefore, the effectiveness of these next-generation smallpox vaccines may be based on animal efficacy data, if scientifically appropriate, and to comparative human immune response data. As for any biologic product, licensure of new smallpox vaccines requires demonstration of safety, purity, and potency.

The public workshop will: (1) Discuss regulatory challenges and approaches related to the licensure of next-generation smallpox vaccines; (2) discuss the strengths and weaknesses of various animal models relative to their ability to mimic human disease that can be used to predict the effectiveness of next-generation smallpox vaccines in humans; (3) discuss the most appropriate methods to bridge immunogenicity of next-generation smallpox vaccines to licensed smallpox vaccines in clinical trials; and (4) discuss viable methods of extrapolating clinical efficacy of next-generation smallpox vaccines from immunogenicity and efficacy data from relevant animal models.

Transcripts: Transcripts of the public workshop may be requested in writing from the Division of Freedom of Information Office (ELEM-1029), Food and Drug Administration, 12420 Parklawn Dr., Element Bldg., Rockville, MD 20857, approximately 15 working days after the public workshop at a cost of 10 cents per page. A transcript of the public workshop will be available on the Internet at http://www.fda.gov/​BiologicsBloodVaccines/​NewsEvents/​WorkshopsMeetingsConferences/​TranscriptsMinutes/​default.htm.

Dated: August 4, 2011.

Leslie Kux,

Acting Assistant Commissioner for Policy.