MAINTENANCE OF CD4+ CELLS BY THYMOPENTIN IN ASYMPTOMATIC HIV-INFECTED SUBJECTS - RESULTS OF A DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY

Objective: To assess the efficacy and safety of thymopentin in HIV-infected patients who had not yet developed AIDS. Design: Patients were stratified into asymptomatic or symptomatic groups and randomized to receive either thymopentin (50 mg) or placebo, subcutaneously, double-blind for 24 or 52 weeks, three times a week. Setting: Patients were enrolled at three sites (two hospital clinics and one private practice). Patients: Of 91 HIV-seropositive patients (52 asymptomatic and 39 symptomatic) from whom HIV could be isolated from peripheral blood, 45 were enrolled for 24 weeks and 46 for 52 weeks of double-blind evaluation. Main outcome measures: Virological, immunological and clinical evaluations were performed before and during treatment. Results: Thymopentin-treated asymptomatic patients had more CD4+ cells, as demonstrated by a greater area under the percentage CD4+ cells curve (P = 0.03) and a shorter median time to a 20% increase in percentage of CD4+ cells (P = 0.04) in the first 24 weeks, with similar trends in the 52-week study. By 24 weeks no asymptomatic thymopentin-treated and two placebo-treated patients (9.1%, Kaplan-Meier estimate) had progressed to constitutional symptoms (P = 0.12; two-tailed Wilcoxon-Gehan test), with only one further progression in a placebo-treated patient in the subset followed for 52 weeks. Symptomatic patients receiving thymopentin or placebo were similar in both CD4+ cell levels and disease progression (two progressions to AIDS in each group). No serious adverse effects attributable to thymopentin were observed. Conclusions: These results, if confirmed, indicate that thymopentin, by maintaining CD4+ cells, could slow or arrest immune decline and consequent disease progression at the asymptomatic stage of HIV infection.