



Switch From Protease Inhibitor regimen to Once Daily Efavirenz Regimen Including FTC & ddI
Reported by Jules Levin



This study (poster #551. Retrovirus Conference 2003, Feb 1014) looked at patients who had undetectable HIV viral load (<400 copies/ml) using a protease inhibitor (PI) regimen and either remained the same therapy or switched to a once daily efavirenz based regimen. Patients had <400 copies/ml for 6 months prior to this study and were taking 2 NRTIs plus 1 or 2 protease inhibitors. They had never taken ddI before and were NNRTInaive. This was a randomized, noninferiority, openlabel study. The once daily regimen consisted of 5 pills taken at bedtime of emtricitabine (FTC), ddI, and efavirenz.
Before switching regimens, at the study baseline, the patients in the switch and PIbased regimens had comparable characteristics in terms of stage of HIV disease, HIVRNA (% <400 copies/ml), and CD4 count (519540, median). PI duration was an average of 35 months.
There were 177 patients remaining on the PI regimen and 178 who switched to the once daily regimen. After 48 weeks there were 151 patients (85%) on the PI regimen and 155 (87%) on the once daily regimen.
Week 48 Results
There was no difference in the probability of virologic failure based on intenttotreat available data using KaplanMeier estimation and 95% CI (8% PIregimen vs 5% once daily, p=0.66).
At week 48, 95% of patients (n=168) on the once daily regimen had <50 copies/ml vs 87% of the patients (n=163) remaining on the PI regimen (p=0.01).
There was no difference in CD4 count at week 48, as counts improved in both patient groups by 15%.
There was no difference between the 2 groups in terms of the probability of a first serious adverse event (15% vs 14%).
Fasting triglycerides: there was no difference at week 48 between the 2 groups (p=0.17).
Median Fasting HDL cholesterol (good cholesterol) increased by 20% for patients on the oncedaily EFV regimen and remained the same for patients on the PI regimen
Treatment discontinuation: the probability of treatment discontinuation was the same in both groups (12% vs 10%, p=0.88)
Fasting LDL (bad cholesterol): there was no significant difference at week 48 between the 2 regimens.







