Antiretroviral drug reduction in highly experienced HIV-infected patients receiving a multidrug regimen: the ECOVIR study.

Objectives: In a context of life-long therapy, we asked whether it could be possible to reduce the number of antiretroviral drugs without jeopardizing viral suppression.
Methods: ECOVIR was a prospective study aiming to assess whether in patients on combination ART with ≥4 antiretrovirals for ≥24 weeks and virally suppressed for ≥48 weeks, a drug-reduced (DR) regimen could be proposed. The intervention consisted of discontinuing genotypically less susceptible drugs to reach a DR regimen with ≤3 antiretrovirals. The primary endpoint was the proportion of patients maintaining viral suppression at week (W) 24.
Results: From 89 eligible individuals for the study, a DR regimen was proposed in 86 (97%) patients, of whom 71 were switched to a DR regimen. Baseline characteristics [median (IQR)] were: age 58 (53-65) years, duration of treatment 24 (21-26) years and viral suppression 8 (6-11) years. The cumulative resistance profile showed full resistance to lamivudine/emtricitabine (91%), abacavir (74%), efavirenz/nevirapine (70%), rilpivirine (56%), darunavir (q24h/q12h) (42%/29%), lopinavir (69%), atazanavir (71%) and raltegravir (24%). The final DR regimen consisted of a two-drug or three-drug regimen in 54 patients (76%) and in 17 patients (24%), respectively. The success rate of a DR regimen at W24 was 93.9% (95% CI 84.4-97.6, Kaplan-Meier estimate). Four patients experienced virological failure (at W4, W8 and W12), all with plasma viral load (pVL) <600 copies/mL and no emergence of resistance mutations. The DR strategy allowed a monthly cost saving of 36%.
Conclusions: In experienced patients with high-level resistance, individualized strategies based on expert advice can offer DR regimen options with fewer drug-drug interactions and a significant economic impact while ensuring virological success.
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