INFLUENCE OF RISK FOR DISEASE PROGRESSION ON RESPONSE TO ANTIRETROVIRAL THERAPY

这是一项随机、双盲临床试验，受试者患有 ZDV/ddI或ZDV/ddC联合治疗的长期既往经验。 合格的受试者是ACTG 175中的参与者， 最初分配的联合治疗，直至ACTG随访结束 175例，或交叉至其中一种联合治疗（由于 CD 4+细胞计数基线下降50%或发生重大 HIV相关疾病）。他们肯定也一直在那个组合上 数据收集结束之间的任何间隔期的治疗， ACTG 175（1995年2月28日）和进入ACTG 303。 受试者将被随机分配至三个治疗组之一： 继续其ZDV/ddI或ZDV/ddC，或将3 TC添加到其ZDV/ddI或 ZDV/ddC，或切换到ZDV/3 TC。 本研究将部分设盲， 受试者将服用ddI或ddI安慰剂，或ddC或ddC安慰剂， 以及3 TC安慰剂。 主要结果指标是HIV RNA的变化 副本编号。 研究治疗的持续时间计划为48周。

This is a randomized, double-blind clinical trial involving subjects with prolonged prior experience with ZDV/ddI or ZDV/ddC combination therapies. Eligible subjects are participants in ACTG 175 who remanied of their initially assigned combination therapy until the end of follow-up in ACTG 175, or were crossed over to one of the combination therapies (because of a 50% deline for baseline in CD4+ cell count or the development of major HIV-related disease). They must also have remained on that combination therapy for any intervening period between the end of data collection for ACTG 175 (Feb 28,1995) and entry into ACTG 303. Subjects will be randomized to one of three treatment arms: eith to continue their ZDV/ddI or ZDV/ddC, or to add 3TC to their ZDV/ddI or ZDV/ddC, or to switch to ZDV/3TC. The study will be partially blinded in that subjects will take either ddI or ddI placebo, or ddC or ddC placebo, as well as 3TC placebo. The primary outcome measure is change in HIV RNA copy number. The duration of study treatment is planned to be 48 weeks.