FDA approves St. Jude safety trial for second part of three-part vaccine to prevent AIDS
Memphis, Tennessee

St. Jude Children's Research Hospital has received approval from the Food and Drug Administration (FDA) to begin testing another part of its HIV vaccine regimen. The hospital will now begin Phase I clinical trials for the second part of a three-tiered HIV vaccine designed to protect against diverse forms of the AIDS virus.

One of the vaccine components was previously approved by the FDA and is currently in safety trials at St. Jude. The final component has recently been submitted for FDA approval.

“We expect to begin recruiting volunteers for the Phase I safety trial of the new vaccine component this summer,” said Karen Slobod, M.D., an associate member of the St. Jude Department of Infectious Diseases.

Each component is being tested in independent safety trials before the three separate vaccine elements will be combined in a sequential series of inoculations.

“Once all three components complete Phase I safety testing individually, they will be combined in a prime-boost-boost regimen for efficacy testing in a larger group of volunteers,” Slobod said.

Slobod and Julia Hurwitz, Ph.D., of the St. Jude Immunology Department, are the leaders of the vaccine project.

The St. Jude HIV vaccine is designed to overcome the problem of viral diversity that is typical of HIV. This vaccine is the first to have advanced a multi-envelope vaccine strategy into clinical testing. Envelope is the protein that coats HIV and is the part of the virus first recognized by the immune system.

This St. Jude multi-envelope HIV vaccine, which was conceived by Slobod and Hurwitz at St. Jude in 1993, is significantly broader in scope than any other HIV vaccine. Designed as a three-tiered approach to stimulate the immune system with many HIV envelope variants, the vaccine includes:

1) a primer composed of DNA that represents more than 50 HIV envelope proteins;

2) a booster with genetically modified vaccinia virus representing more than 20 HIV envelope proteins; and

3) a second booster with purified HIV envelope protein.

“By acknowledging the structural diversity of HIV envelope and designing a vaccine that encompasses diversity, St. Jude hopes to produce a successful vaccine,” Hurwitz said. “Such a vaccine is designed to help people of all ages, but St. Jude is particularly interested in making a vaccine available to the world’s children.”

Work on the St. Jude HIV vaccine is supported by the National Institutes of Health, The Pendleton Foundation and ALSAC.

St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tennessee, St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization.