PHASE-II CONTROLLED TRIAL OF POSTEXPOSURE IMMUNIZATION WITH RECOMBINANT GP160 VERSUS ANTIRETROVIRAL THERAPY IN ASYMPTOMATIC HIV-1-INFECTED ADULTS

Objective: To alter the natural course of HIV-1 infection by inducing or potentiating immune responses to HIV-1 envelope glycoprotein. Desig n: Multicentre, double-blind, three-arm, placebo-controlled study. Set ting: Outpatients attending clinics in two University Hospitals. Patie nts: Ninety-nine asymptomatic HIV-1-infected adults with CD4+ T-cell c ounts > 400 and < 600 x 10(6)/l and no previous antiretroviral therapy were included. Interventions: Patients were randomly assigned to thre e groups treated with: (i) gp160 in alum over a 2-year period in combi nation with placebo for the full study duration (n = 32); (ii) gp160 i n alum over a 2-year period in combination with zidovudine for the ful l study duration (n = 34); and (iii) alum over a 2-year period in comb ination with zidovudine for the full study duration (n = 33). Results: Immunotherapy was well tolerated and no significant differences in di sease progression were seen in the treatment groups. The majority of p atients (85%) receiving gp160 showed persistent lymphoproliferative re sponses to the immunogen and to a different Env antigen preparation. C D4+ cell count changes in patients receiving zidovudine alone were sig nificantly higher than those seen in patients receiving immunotherapy alone after 1 year of treatment. Zidovudine administration was associa ted with initial transient reduction of plasma viraemia. Conclusions: Prolonged immunization with a soluble HIV-1 subunit provided no benefi t to asymptomatic HIV-1-infected patients and was inferior to zidovudi ne monotherapy. Furthermore, immunization with gp160 shortened the dur ation of the transient viral load reduction induced by zidovudine. (C) 1998 Rapid Science Ltd.