Predictors of the virological response to a change in the antiretroviral treatment regimen in HIV-1-infected patients enrolled in a randomized trial comparing genotyping, phenotyping and standard of care (Narval trial, ANRS 088).
OBJECTIVE
To identify predictors of the virological response to antiretroviral therapy in patients in whom initial therapy has failed.


METHODS
The Narval trial was designed to compare phenotyping, genotyping and standard of care for the choice of antiretroviral therapy in patients in whom a protease inhibitor (PI)-containing regimen had failed. Virological success was defined as viral load below 200 copies/ml at week 12. Baseline variables including demographic, clinical and biological characteristics, HIV reverse transcriptase and protease mutations, the randomization arm, the drugs prescribed, as well as adherence to treatment and plasma concentrations of PIs and non-nucleoside reverse transcriptase inhibitors (NNRTIs) at week 12 were tested in the model. Variables that were significantly associated with virological success in univariate analysis were included in a logistic regression model.


RESULTS
Five-hundred-and-forty-one patients were randomized. Virological success at week 12 was obtained in 200 patients. In multivariate analysis, the following factors were significantly associated with virological success: prescription of efavirenz to NNRTI-naive patients (OR=4.37; 95% CI: 2.76-6.90), randomization to the genotyping arm (OR=2.13, 1.20-3.79), prescription of lamivudine (OR=1.69, 1.01-2.83) and prescription of abacavir to abacavir-naive patients (OR=1.66, 1.02-2.72). Factors significantly associated with virological failure were prescription of nelfinavir (OR=0.30, 0.13-0.68), a high baseline viral load (OR=0.37, 0.28-0.50), the presence of at least five PI mutations (OR=0.42, 0.26-0.66), the presence of at least three thymidine analogue mutations (OR=0.61, 0.39-0.97) and at least 30 months of prior PI exposure (OR=0.64, 0.41-0.99).


CONCLUSIONS
These results confirm that among heavily pretreated patients, prescription of efavirenz to NNRTI-naive patients is associated with a good virological response, while a high baseline viral load, a large number of PI mutations and nelfinavir prescription at baseline are associated with a poor virological response. Genotyping was found to be beneficial, while this was not the case for phenotyping. This work was presented at the XI International HIV Drug Resistance Workshop, Sevilla, Spain, July 3-6 2002 (Abstract N(o)133); and at the XIV International Conference on AIDS, Barcelona, Spain, July 7-11 2002 (Abstract N(o)ThOrB138).
Vray
Muriel
M
INSERM EMI 0214, Université Pierre et Marie Curie, Paris, France. murielvray@hotmail.com
Meynard
Jean-Luc
JL
Dalban
Cécile
C
Morand-Joubert
Laurence
L
Clavel
François
F
Brun-Vézinet
Françoise
F
Peytavin
Gilles
G
Costagliola
Dominique
D
Girard
Pierre-Marie
PM
D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use*; D024882:Drug Resistance, Viral / Q000235:genetics*; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D016333:HIV Protease / Q000235:genetics; D017320:HIV Protease Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011237:Predictive Value of Tests; D012367:RNA, Viral / Q000097:blood*; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase; D016333:HIV Protease