8th Conference on Retroviruses and Opportunistic Infections Chicago, IL - February 4 - 8, 2001

Conf Retroviruses Opportunistic Infect 2001 Feb 4-8; 8:48 (abstract no. 18)

C. Van Der Horst¹, I. Sanne², C. Wakeford³, J. Quinn³, and F. Rousseau^3
1Univ. of North Carolina, Chapel Hill;²Parktown, South Africa; and³Triangle Inc., Durham, NC.

BACKGROUND: FTC is a NRTI that has in vitro potency against HIV which is 4-10 times greater than 3TC and has shown approximately a 2 log₁₀ median decrease in viral load when used at 200 mg once daily (QD) in a two week monotherapy study. To examine the efficacy and safety of FTC, we conducted two randomized, controlled equivalence trials of 150 mg 3TC BID compared with 200 mg FTC QD in triple therapy combination regimens.

METHODS: FTC-303 was a randomized, open-label switch study in HIV-1 infected patients (≤ 400 copies/mL) on a 3TC containing triple therapy regimen for ≥ 12 weeks. Patients were randomized to switch to FTC or continue on 3TC in a 2: 1 ratio. FTC-302 was a randomized, double blind study comparing FTC to 3TC in a background of stavudine and either nevirapine (NVP) or efavirenz in ART naïve HIV-infected patients. In both studies, patients were monitored every 4 weeks for adverse events (AEs) and viral load was assessed every 4 to 12 weeks. Virological failure (VF) was defined as 2 consecutive visits >400 copies/mL. Treatment arms were compared using a 95% confidence interval for the difference in the proportion of VF at week 48 (FTC-303) or week 24 (FTC-302).

RESULTS: 440 and 468 patients were enrolled in FTC-303 and FTC-302, respectively. FTC and 3TC were well tolerated by the majority of patients; AEs were predominantly mild to moderate in both groups. There have been 58 patients in study FTC-302 who experienced grade 3 or grade 4 hepatotoxicity, all within the NVP stratum. Less than 12% of the patients in either study have experienced VF to date. The 95% CI for the difference between FTC and 3TC in the proportion of VF was (-4.1, 3.6) at week 48 in study FTC-303 and (- 2.0, 9.0) at week 24 in study FTC-302.

CONCLUSIONS: These findings support equivalent antiviral efficacy and safety at one-daily FTC compared to twice daily 3TC in HIV-1 infected patients initiating therapy or switching from 3TC to FTC with HIV-1 RNA ≤ 400 copies/mL.

2001-02-04
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Copyright © 2001 - Foundation for Retrovirology and Human Health. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Foundation for Retrovirology and Human Health. Licensed (AIDSLINE) from National Library of Medicine.