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14th International AIDS ConferenceBarcelona, Spain — July 7-12, 2002 |
Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. ThOrB1388
BACKGROUND: To evaluate the prevalence, associated factors and clinical significance of NNRTI hypersusceptibility (NNRTI-HS)
METHODS: Patients without prior NNRTI therapy who were failing (HIV RNA > 400) stable antiretroviral therapy had ViroLogic phenotype assay, HIV RNA, and CD4 cell counts before changing to a new NNRTI containing regimen at baseline. NNRTI HS was defined as a fold change in IC50 of less than 0.4 (patient compared to reference control).
RESULTS: At baseline, the 177 patients had a mean HIV RNA of 4.1 log10, CD4 cell count of 322 and a mean of 41 months of prior treatment. NNRTI-HS was common: EFV-HS = 24%, DLV-HS = 17.5%, and NVP = 20%. EFV-HS was associated with duration of previous NRTI use (p < .001), number of nucleoside agents (p = .002), use of ZDV (p = 0.04), and reduced susceptibility to ZDV and ABC (fold change in IC50 > 5.0 compared to control, p< .005). The mean change in HIV RNA (area based measure) 6 months after starting a new NNRTI based regimen was greater in the 21 patients with NNRTI hypersusceptible virus compared to the 77 patients without HS (1.2 versus 0.8 reduction in log10 HIV RNA; p = .016). The difference persisted at month 12 (p = .023). Multiple linear regression models confirmed that HS to NNRTI was a significant independent predictor of the magnitude of early HIV RNA reduction (up to month 4), after accounting for the baseline HIV RNA and the number of newly prescribed drugs to which the patient's virus was susceptible (p < .02). CD4 cell increases were also greater for patients with HS virus. Between months 4 to 12, the average additional CD4 gain in those with NNRTI HS was 28- 60, differences that trended toward significance at months 4, 6, and 10.
CONCLUSIONS: NNRTI HS occurred in about 20% of nucleoside experienced patients and, in those who initiated a NNRTI, appeared to result in greater reduction of HIV RNA and CD4 cell gain for up to one year.
Presenting author: R Haubrich
1UCSD, San Diego, CA, United States
2ViroLogic, South San Francisco, United States
3UT Southwestern, Dallas, United States
4SCVMC, San Jose, United States
5Harbor- UCLA, Los Angeles, United States
6UCI, Irvine, United States
7USC, Los Angeles, United States
8UCLA, Los Angeles, United States
9UCSD, SD VA, La Jolla, United States
10United States
020711
ThOrB1388
Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.
