Prolonged zidovudine therapy in patients with AIDS and advanced AIDS-related complex. AZT Collaborative Working Group

We examined the long-term safety and efficacy of zidovudine therapy in 229 subjects with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex who previously participated in a placebo-controlled study of zidovudine. One hundred two placebo recipients (delayed treatment group) and 127 zidovudine recipients (original treatment group) were followed up while receiving zidovudine therapy for a mean of 21 months. Survival rates for the original treatment group were 84.5% and 57.6% at 12 and 21 months, respectively; for the delayed treatment group, 78.8% and 64.6% at 12 and 21 months, respectively, and 78.8% and 47.5% at 12 and 21 months, respectively, for 77 subjects with AIDS and 93.0% and 71.8%, respectively, for 50 subjects with AIDS-related complex in the original treatment group. Adverse reactions decreased over time and newly observed toxic reactions were unusual. The clinical course of these subjects suggests continued survival benefits with long-term zidovudine therapy.