Viagene Inc. announced Thursday that it has filed with the FDAto begin trials of a gene transfer therapy for AIDS.
The company's HIV ImmunoTherapeutic uses a geneticallyengineered murine retrovirus to deliver into cells a genesequence that codes for the production of HIV antigens. Theantigens then are produced intracellularly.
The therapy is designed to stimulate a patient's immunesystem to mount a cytotoxic T-lymphocyte (CTL) responseagainst HIV infected cells. The company said it stimulated highlevels of HIV-specific CTLs without producing toxic or otheradverse side effects in preclinical mouse and primate studies.
Viagene plans to begin Phase I trials in the third quarter inpre-AIDS, HIV infected patients. It takes about four months toprepare the material for an individual patient.
The gene transfer therapy starts with culturing of fibroblastsfrom skin cells taken from the patient. The vector product isadministered to the cells, which are then irradiated so thatthey are non-proliferating. The cultures are frozen and quality-control tests are performed. Finally, they are thawed andinjected into the patient's arm. Each patient receives severalinjections over the course of several weeks.
The FDA regulates gene therapy more closely than conventionaldrugs and biologics. Requests for investigational new drugclearance for gene therapies must be submitted to an FDAadvisory panel. Normally advisory committees are convenedonly to consider marketing approval of new drugs. Viageneexpects to submit its IND to the Vaccine Advisory Committee inJune.
The San Diego company is developing its HIVImmunoTherapeutic under an agreement with The Green CrossCorp. of Japan. Green Cross has an equity investment of $4.75million in Viagene and is funding development of the therapy.Total funding for the four-year development program, whichstarted in 1990, could total $40 million, according to RobertAbbott, Viagene president and CEO.
Green Cross will receive exclusive worldwide marketing rights.Viagene retained the right to supply all product and willreceive royalties.
-- Steve Usdin BioWorld Washington Bureau
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