COMPARATIVE STUDY OF THE ANTIVIRAL EFFECT OF A STANDARD TRIPLE DRUG REGIMEN (SDR) AGAINST A ONCE DAILY INVESTIGATIONAL DRUG REGIMEN (IDR): CTN 118

DP Zarowny, L McAfee, J Gill, J Gilmour, M Harris, R Lalonde, D Rouleau, F Smaill, C Tsoukas, JSG Montaner, Canadian HIV Trials Network

Objectives: In a prospective, randomized, open-label trial, to compare the antiviral effect and safety of an IDR given once daily (adefovir, ddI, 3TC, nevirapine) to a SDR consisting of two NRTIs and a PI (selected by the treating physician).
Methods: HIV+ antiretroviral (ARV)-naïve adults with HIV RNA >10,000 copies/mL and CD4 counts >70 cells/mm³ were randomly assigned to receive IDR or SDR for 28 weeks. At baseline and every 4 weeks, physical exam, viral load (VL), CD4 cell count, hematology, biochemistry and urinalysis were done.
Results: 27 patients were recruited at 7 sites before the trial was discontinued due to concerns regarding safety of the IDR. Two SDR patients withdrew consent after randomization and did not take study drugs. Baseline laboratory parameters were not significantly different between the two arms (t-test, Wilcoxon). Median baseline CD4 and VL, proportions of patients with VL<50 copies/mL (PVL<50), and median CD4 changes (DCD4) at 12 and 24 weeks are shown.

Two patients in IDR arm discontinued ARV therapy after 47 days (deep vein thrombosis) and 89 days (elevated liver enzymes). No other clinically significant changes in laboratory values, including creatinine, were seen in either arm.
Conclusions: A once daily ARV regimen of adefovir, ddI, 3TC and nevirapine was as effective and well-tolerated as a standard regimen including a PI in a small group of ARV-naïve patients over 24 weeks.