Background:  Our 48-week results of E-184V study show that lamivudine (3TC)  monotherapy, in failing HIV-1-infected patients harboring the M184V mutation, may provide a better immunological and clinical outcome than complete therapy interruption. We present the results of the 144-week follow-up.

Methods:  After 48 weeks, patients enrolled in the E-184V study were maintained to the randomized treatment (3TC or therapy interruption) and followed. HAART was resumed only in case of immunological failure (CD4 <350 cells/mm³) or clinical failure (the occurrence of a B or C CDC event). Statistical analysis was intent-to-treat ANOVA for repeated measures was applied.

Results:  At baseline, the treatment interruption-group and the 3TC-group median (IQR) CD4 cells/mm³, CD4%, HIV RNA log₁₀ copies/mL, nadir CD4 cells/mm³, CD4/CD8 were:  566 (472 to 636), 27.8 (25.1 to 33.6), 3.7 (3.3 to 4.2), 261 (172 to 366), 0.63 (0.49 to 0.77), and 580 (463 to 630), 23.3 (20.3 to 29.0), 3.8 (3.5 to 4.0), 304 (251 to 427), and 0.51 (0.36 to 0.69), respectively. No statistical difference between the 2 groups occurred, with the exception of CD4% (p = 0.0501). In therapy interruption-group, median time to immunological or clinical failure was 20 weeks whereas in the 3TC group 50% of patients failed within 84 weeks (log-rank p = 0.053). Between weeks 48 and 144, no patient exhibited disease progression. At week 144, mean (±SE) CD4 and HIV RNA log₁₀ changes from baseline were as presented in the table. At ANOVA analysis, CD4, CD4%, and CD4/CD8 significantly varied with long time (p <0.0001, p <0.0001, and p <0.0001) and these variations were different between both treatment arms (p = 0.0095, p = 0.0003, and p <0.0001), different according to baseline CD4 (≤700 vs >700) (p <0.0001, p = 0.0008, and p = 0.0008) and different when both considering treatment and baseline CD4 (p = 0.0053, p = 0.0215, and p <0.0001). HIV RNA had significant variation along time (p <0.0001) without significant differences between the 3TC and the treatment interruption group (p = 0.0593). Conclusions:  In patients failing on 3TC-conatining HAART, this 144-week follow-up confirms that maintenance of 3TC monotherapy provides a persistently better immunological outcome than treatment interruption.