A randomized, controlled trial of initial anti-retroviral therapy with abacavir/lamivudine/zidovudine twice-daily compared to atazanavir once-daily with lamivudine/zidovudine twice-daily in HIV-infected patients over 48 weeks (ESS100327, the ACTION Study)

Table 4 Summary of Protocol-Defined Virologic Failure and Drug Resistance at Week 48

	ABC/3TC/ZDV (N = 138)	ATV+3TC/ZDV (N = 140)
Virologic Responders	120 (87%)	123 (88%)
Protocol-Defined Virologic Failures	18 (13%)	17 (12%)
1. Less than 1 log₁₀ reduction in baseline plasma HIV-1 RNA by week 12	3	3
2. Reduction of plasma HIV-1 RNA < 50 copies/mL on two occasions with a subsequent increase to ≥ 400 copies/mL on two consecutive occasions prior to week 24	2	2
3. Failure to achieve plasma HIV-1 RNA < 400 copies/mL by Week 24	3	4
4. Plasma HIV-1 RNA ≥ 400 copies/mL on consecutive occasions after Week 24	6	11
5. Plasma HIV-1 RNA ≥ 400 copies/mL at Week 48 without confirmation	7	3
Subjects meeting multiple virologic failure criteria ¹	3	5
Post-Baseline Genotype and Phenotype	17	16
Subjects with treatment-emergent mutations	10	11
Any NRTI-associated Mutations ²	8	9
(M184V, M184M/V, L74V, L74I/V D67N, L210W)
Any PI-associated mutations	7	6
(G16E, K20M, L24I, L33V, I54I/L, I62V, V77I, I85I/V, I93I/L)
Any NNRTI-associated mutations	0	1
(K103N)

Note: Genotype at screening was not performed.
1. In the ABC/3TC/ZDV group, 1 subject met both criteria 2 and 5 and 2 subjects met both criteria 4 and 5; In the ATV+3TC/ZDV group, 1 subject met criteria 2 and 4, 3 subjects met criteria 3 and 4, and 1 subject met criteria 4 and 5.
2. Treatment-emergent mutations that were considered non-significant that also developed included: F77L, I13V, L63L/P, L63P, and E35G.

ISSN: 1742-6405