Zidovudine plus interferon-alpha versus zidovudine alone in HIV-infected symptomatic or asymptomatic persons with CD4+ cell counts > 150 x 10(6)/L: results of the Zidon trial. Zidon Study Group.

Objective: To evaluate the efficacy and safety of zidovudine (ZDV) and lymphoblastoid interferon (IFN)-alpha combination therapy compared with ZDV monotherapy in HIV-infected subjects with CD4+ cell counts between 150 and 500 x 10(6)/l.

Design: Open, randomized controlled trial with subjects stratified by the Centers for Disease Control and Prevention (CDC) 1986 classification of HIV disease (group II/III or IV). The study was amended to a sequential design in February 1992 to allow interim analyses to be conducted.