Revista de SIDA e investigación clínica

Low-Dose Ritonavir-Boosted Atazanavir (200/100 mg) Maintained a High Virological Efficacy Up To 4 Years in Treatment-Experienced HIV-1 Infected Adults: A Prospective Cohort Study from Asia

Abstract

Anchalee Avihingsanon, Tanakorn Apornpong, Stephen J Kerr, Wirach Make-a-nantawat, Narukjaporn Thammajaruk, Supalak Phonphithak, Reshmie A Ramautarsing, Amanda Clarke, Praphan Phanuphak, David M Burger, Kiat Ruxrungtham and HIV-NAT 006 Study Team

Background: HIV requires lifelong treatment so ARV dose optimization is important for long-term efficacy and safety. Previously, low-dose atazanavir (ATV)/ritonavir(r) plus 2 NRTIs in HIV-infected Thai patients provided adequate plasma ATV concentrations and reduced risk of hyperbilirubinemia. However, long-term efficacy and safety data is limited.

Methods: 127 HIV-infected adults on ATV/r200/100mg plus 2 NRTIs were prospectively followed in Thailand. CD4 cell counts, HIV-RNA, and safety parameters were performed every 6 months. Estimated glomerular filtration rate (eGFR) was calculated by chronic kidney disease epidemiology (CKD-EPI). ATV plasma concentrations (ATV Ctrough) were assessed.

Results: Median body weight was 60 kg and 50% were females. Previous regimens were mainly standard dose ATV/r (54%) and lopinavir/r (29%). 93% of them were on tenofovir and 9.4% had HIV-RNA > 50 copies/mL at the time when lower dose of ATV/r was initiated. The median duration of lower dose ATV/r was 154 (IQR 65-271) weeks and 50.4% had been followed for more than 3 years. HIV-RNA < 50 copies/mL by on-treatment and intention-to-treat analysis were 91.2% and 81.8%, respectively. Bilirubin and eGFR significantly improved [83 to 88 ml/min/1.73m2 (p<0.001)]. Premature discontinuation occurred in 13 (10.2%) patients due to toxicity (CKD, renal stone, hepatitis, pancreatitis) and death (sepsis, cerebral aneurysm, CKD). All 42 cases with available ATV Ctrough had adequate ATV concentrations of >0.15 mg/L.

Conclusions: Long-term use of ATV/r 200 mg/100 mg based-HAART as a maintenance therapy for patients who are sensitive to PI was efficacious and well-tolerated. Use of low-dose ATV/r could benefit resource limited settings because it will reduce toxicity, increase accessibility and save costs.