The Effect of Nevirapine in Combination With Nelfinavir in Heavily Pretreated HIV-1–Infected Patients: A Prospective, Open-Label, Controlled, Randomized Study

Virological and immunological impact of non-nucleoside reverse transcriptase inhibitor withdrawal in HIV-infected patients with multiple treatment failures

No significant changes in viral load and CD4 cell count were observed 2-4 weeks after the withdrawal of non-nucleoside reverse transcriptase inhibitors (NNRTI) from the current therapy of patients exhibiting resistance mutations to this class of drugs. The data suggest that in the presence of specific resistance mutations NNRTIexert no residual antiretroviral activity and could be withdrawn without viral rebound.

Low nevirapine plasma concentrations predict virological failure in an unselected HIV-1-infected population

OBJECTIVE

To assess the relationship between plasma nevirapine concentrations and plasma HIV-1 RNA response in HIV-1-infected patients.

DESIGN

An observational cohort analysis.

METHODS

Plasma samples were obtained on a routine basis from 189 patients receiving nevirapine 200mg twice daily, and plasma nevirapine concentrations were measured with reversed phase high performance liquid chromatography. Patients were divided into two groups based on plasma nevirapine concentrations below (and equal to) or above 3 mg/L. The association between steady-state nevirapine concentrations and plasma HIV-1 RNA was determined by multivariate analysis.

RESULTS

Out of 189 patients, 13 (7%) had low nevirapine plasma concentrations and 176 patients had concentrations above 3 mg/L. In total, 22 (12%) patients showed virological failure and 8 patients (4%) discontinued nevirapine because of adverse effects. The risk of failure in patients with nevirapine plasma concentrations </=3mg/L was increased (relative risk 5.0, 95% CI 1.8-13.7). Rashes and liver enzyme elevations each occurred in 8% of patients.

CONCLUSIONS

Low nevirapine drug concentrations are predictive of virological failure.

Prospective comparison of first-line nelfinavir therapy versus nelfinavir introduction in rescue antiretroviral regimens

In order to establish the role of the protease inhibitor nelfinavir in current clinical practice, a prospective 18-month open-label comparison of efficacy and tolerability of nelfinavir was performed among HIV-infected patients who either incorporated nelfinavir in their first-line highly active antiretroviral therapy (HAART) regimen (group A, 57 patients), or who added nelfinavir to a rescue antiretroviral regimen (following at least two attempts with protease inhibitor-based HAART) (group B, 67 patients). All evaluable data were analyzed according to the prior and concurrent antiretroviral therapy, including genotypic resistance assays for patients undergoing salvage therapy. A significantly better virologic outcome (as expressed by a > 2 log(10) drop of plasma viremia versus baseline or attainment of undetectable levels), was shown among patients belonging to group A versus group B, where a number of genotypic mutations possibly elicited by previous anti-HIV treatment strongly impaired a potent and sustained nelfinavir activity. On the whole, the immunologic response (as expressed by the mean CD4(+) lymphocyte count versus baseline), substantially paralleled the virologic one in all analyzed subgroups, but a tendency toward a maintained immunologic competence was also observed in the majority of patients experiencing virologic failure. Nelfinavir introduction was sufficiently safe, because a limited percentage of patients suffered from mild-to-moderate, novel, or continuing adverse events, which proved significantly more frequent in the salvage group but did not affect adherence to HAART.