Response to first protease inhibitor- and efavirenz-containing antiretroviral combination therapy. The Swiss HIV Cohort Study.
OBJECTIVE
To compare the response to protease inhibitor (PI) and efavirenz-containing combination therapy among treatment-naive HIV-infected persons.


METHODS
Prospective observational cohort study.


METHODS
Response to treatment was analysed according to the intent-to-treat principle among antiretroviral-naive patients who started either efavirenz (n = 89) or PI (n = 183) plus two nucleoside reverse transcriptase inhibitors between February 1999 and March 2000 using Kaplan-Meier and multivariable Cox proportional hazard regression methods. Primary endpoint was time to undetectable plasma viral load. Secondary endpoints included the number of CD4 cells gained, virological rebound, treatment change, and clinical progression.


RESULTS
Patients on PI regimens had lower median CD4 counts (165 versus 216 x 5 106/l; P = 0.15) and were more likely to have AIDS at initiation of treatment (25% versus 15% P = 0.048) than patients starting efavirenz regimens. The probability of reaching plasma HIV-1 RNA < 400 copies/ml was higher with efavirenz- than with PI-containing regimens [adjusted hazard ratio, 1.75; 95% confidence interval (CI), 1.34-2.29]. Median times to undetectable viral load were 58 days (95% CI, 44-70 days) for efavirenz-treated and 88 days (95% CI, 79-98 days) for PI-treated patients. The median number of CD4 cells gained in the first 6 months (90 x 10(6) cells/l with efavirenz, 10(7) x 10(6) cells/l with PI; P = 0.63), time to and reasons for treatment change, time to viral rebound, drug intolerance and clinical progression rates were similar in the two treatment groups.


CONCLUSIONS
Treatment with efavirenz-, compared with PI-based regimens, appeared to result in a superior virological response but no difference in immunological or clinical efficacy. The relevance of these observations remains to be determined in studies with longer follow-up.
Friedl
A C
AC
Division of Infectious Diseases and Hospital Epidemiology, Department of Internal Medicine, University Hospital Zurich, Switzerland.
Ledergerber
B
B
Flepp
M
M
Hirschel
B
B
Telenti
A
A
Furrer
H
H
Bucher
H C
HC
Bernasconi
E
E
Weber
R
R
D000328:Adult; D000368:Aged; D000480:Alkynes; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D048588:Benzoxazines; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D003521:Cyclopropanes; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D015497:HIV-1 / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010078:Oxazines / Q000627:therapeutic use*; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D017320:HIV Protease Inhibitors; D010078:Oxazines; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; C098320:efavirenz