United Biomedical Inc. announced Friday that FDA approved aPhase I trial in healthy volunteers of a synthetic prototypepeptide AIDS vaccine.

The prototype vaccine, described in an October 1991 issue ofScience, produced higher levels of protective antibodies to awider variety of AIDS virus strains over a longer period of timethan other candidate vaccines tested by that time.

The six-month trial in up to 36 people will allow the privatelyheld Hauppauge, N.Y., company to explore how to develop theproduct by examining how "animal results will be translatedinto the human condition," Rosanne Boyle, director ofregulatory affairs, told BioWorld.

The trials will be carried out at the National Institute of Allergyand Infectious Diseases' (NIAID) AIDS Vaccine Clinical TrialsNetwork at two affiliated medical center in the U.S.

The prototype vaccine neutralizes the virus but does not havecytotoxic T cell effect, which might be considered a true endpoint for a vaccine, Boyle said. The company published itsresults so that the scientific community could address otheraspects that would be needed for an efficient vaccine, she said.

The prototype vaccine has eight peptides from the V3 loop ofthe HIV outer envelope, a primary site for antibodies toneutralize the virus. To overcome the small target size andvariability between HIV strains in this loop, UBI synthesizedartificial eight-branched peptides arrayed around a centralcore. This amplifies the immunologic signal, creating a strongresponse in guinea pigs that over time induced antibodiesagainst divergent strains.

The broadened response was considerably accelerated andaccentuated by a "cocktail" of six peptide variantscorresponding to different strains of the virus.

The trials are the first with peptides through the NIAID's AIDSVaccine Clinical Trials Network, Lori Dupell of the office ofcommunications told BioWorld. Others companies are workingon peptide vaccine candidates and have presented results atmeetings, she said.

Repligen Corp., MicroGeneSys Inc., Viral Technologies Inc.,Genentech Inc., Chiron Corp. and Bristol-Myers Squibb haveworked on protein- and peptide-based AIDS vaccines.

"This is the beginning that will allow the technology to bedeveloped to rapidly address parameters needed for a humanvaccine," Boyle said.

She added that the company has some "proprietary positions"with respect to the branching and sequences used in theprototype vaccine, and said its artificial synthesis is"commercially applicable" and more streamlined thanrecombinant methods.

The company began exploring sequences in the humanimmunodeficiency virus that causes AIDS in 1984 and beganvaccine work about two years later, she added.

-- Nancy Garcia Associate Editor

(c) 1997 American Health Consultants. All rights reserved.