The National Institutes of Health (NIH) plans to enroll the firstpatients in its trial of hyperimmune anti-HIV intravenousimmunoglobulin (HIVIG) to prevent maternal-fetal HIVtransmission next week.

HIVIG is a plasma derivative obtained from pooled plasma ofHIV-infected, asymptomatic individuals with high levels of p24antibodies. The plasma is rendered noninfectious and theninfused into patients. The goal of the therapy, also known aspassive hyperimmune therapy, is to have antibodies in theplasma trigger an immune response in the patient to fight theHIV infection.

The first portion of the NIH study, to include up to 20 HIV-positive, asymptomatic pregnant women at nine sites, willcollect safety and pharmacokinetic data. The overall efficacyportion of the study is expected to begin in January with atarget population of 400 pregnant women who are 20-30weeks pregnant and are taking AZT. The women will berandomized to receive either HIVIG or standard intravenousimmune globulin monthly until delivery. They will receive I.V.AZT postpartum and their infants will receive a single dose ofHIVIG or IVIG according to their mother's treatmentassignment within 12 hours of birth. All of the infants will alsoreceive oral AZT for six weeks. The infants will be monitoredfor two years.

The NIH trial has been delayed for over a year. It wasoriginally scheduled to begin last March, but NIH's HIVIGsupplier, Abbott Laboratories of Abbott Park, Ill., canceled itscontract. The company cited fears that it would be subject toliability given the theoretical possibility that HIVIG couldenhance HIV infection. North American Biologics Inc.(NASDAQ:NBIO) is now supplying NIH with the HIVIG rawmaterial. The trial is being co-sponsored by the NationalInstitute of Child Health and Human Development, the NationalHeart, Lung and Blood Institute and the National Institute ofAllergy and Infectious Diseases.

HemaCare Corp. (NASDAQ:HEMA) is the only company pursuingpassive hyperimmune therapy as an AIDS treatment. Itannounced on Wednesday that it has received approval fromthe California Department of Health Services Food and DrugBranch to begin Phase III testing of its Immupath inapproximately 600 patients. In addition, the company plans tofile an investigational new drug (IND) application with the FDAin the near future; HemaCare had a pre-IND meeting with theagency two weeks ago. The California state agency mayapprove the drug for marketing solely in California.

Los Angeles-based HemaCare has been testing Immupath since1990. Earlier this year it reported Phase I/II trial results with220 patients. The 12-month, double-blind, placebo-controlledstudy found positive treatment effects only in patientsreceiving a full dose of 500 milliliters of HIV hyperimmuneplasma who had a baseline CD4 cell count between 50-200 percubic millimeter. Of the 68 patients receiving full dose, 21 hadCD4 counts above 50. Seventy-five patients received a halfdose of the plasma and 77 received placebo.

CD4 cell levels improved an average of 32.7 cells per cubicmillimeter over baseline in the full-dose group versus 0.9 cellsper cubic millimeter in the half-dose group and there was aloss of 3.5 cells per cubic millimeter in the placebo group(p=.043). HemaCare also reported that p24 antibody levelsincreased in both the full- and half-dose groups compared toplacebo, and there appeared to be a concurrent decrease in p24antigen. There was one death in 21 with the full dose, threedeaths in 21 with the half dose and six deaths in 30 with theplacebo. The company found no serious toxicity in any of thepatients.

-- Brenda Sandburg News Editor

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