Plasma HIV-1 RNA decline within the first two weeks of treatment is comparable for nevirapine, efavirenz, or both drugs combined and is not predictive of long-term virologic efficacy: A 2NN substudy.
BACKGROUND
The initial rate of plasma HIV-1 RNA (pVL) decline has been proposed as a marker of early efficacy of antiretroviral therapy (ART) and a possible predictor of late efficacy. We compared the rate of pVL decline in patients starting ART with nevirapine (NVP), efavirenz (EFV), or both drugs combined in addition to lamivudine (3TC) and stavudine (d4T).


METHODS
Analysis of the viral decay constant (VDc) during the first 2 weeks of treatment in patients enrolled in the 2NN study who remained on allocated treatment.


RESULTS
The median VDc (log10 copies per day, [interquartile range]) was similar for NVP (0.30 [0.25-0.36], EFV (0.31 [0.27-0.37]), and NVP + EFV (0.30 [0.27-0.36]). Patients with a baseline pVL >100,000 copies/mL were 8.7 (95% confidence interval [CI]: 6.2-12.3) times more likely to have a VDc >75th percentile. A high VDc was not associated with plasma drug concentration or with a decreased risk of virologic failure at week 48 after the start of therapy (hazard ratio = 0.8, 95% CI: 0.6-1.2).


CONCLUSIONS
NVP, EFV, or NVP + EFV in combination with 3TC and d4T show similar rates of pVL decline during the first 2 weeks of treatment. The VDc with these regimens is not predictive of late virologic efficacy.
van Leth
Frank
F
International Antiviral Therapy Evaluation Center, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, The Netherlands. f.vanleth@iatec.com
Huisamen
Casper B
CB
Badaro
Roberto
R
Vandercam
Bernard
B
de Wet
Joss
J
Montaner
Julio S G
JS
Hall
David B
DB
Wit
Ferdinand W N M
FW
Lange
Joep M A
JM
D000328:Adult; D000480:Alkynes; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use*; D048588:Benzoxazines; D003521:Cyclopropanes; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D019259:Lamivudine / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D019829:Nevirapine / Q000494:pharmacology / Q000627:therapeutic use*; D010078:Oxazines / Q000494:pharmacology / Q000627:therapeutic use*; D016016:Proportional Hazards Models; D012367:RNA, Viral / Q000097:blood*; D018119:Stavudine / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D010078:Oxazines; D012367:RNA, Viral; D019259:Lamivudine; D019829:Nevirapine; D018119:Stavudine; C098320:efavirenz