Integrase
Inhibitor Raltegravir (Isentress) Compares Favorably to Efavirenz (Sustiva) at
144 Weeks in Treatment-naive Patients
 | The
integrase inhibitor raltegravir (Isentress), in combination with tenofovir/lamivudine,
continued to exhibit potent anti-HIV activity at 144 weeks in treatment-naive
patients, suppressing viral load as well as efavirenz (Sustiva) but associated
with fewer side effects. |
By
Liz Highleyman At
the 5th International AIDS Society Conference on HIV Pathogenesis,
Treatment, and Prevention (IAS 2009) this week in Cape Town, South Africa,
researchers from Peru, Canada, and the U.S. presented a poster describing results
from an ongoing Phase 2 study comparing the long-term efficacy, safety, and tolerability
of raltegravir
versus efavirenz in previously
untreated patients. In
this double-blind, multicenter study, 198 treatment-naive participants were randomly
assigned to receive 400 mg twice-daily raltegravir (the first 48 weeks were dose-ranging
from 100 to 600 mg twice-daily) or 600 mg once-daily efavirenz, both combined
with tenofovir (Viread) and lamivudine
(3TC; Epivir). Results 
| At
144 weeks, in a non-completer = failure analysis, 144, 78% of the 160 patients
receiving raltegravir and 76% of the 38 patients taking efavirenz had sustained
HIV RNA suppression < 50 copies/mL. | |
| Only
3 patients met the study's definition of virological failure after week 96, 2
in the raltegravir arm and 1 in the efavirenz arm. | |
| Participant
in both arms experienced similar CD4 cell gains (252 vs 233 cells/mm3, respectively).
| |
| Drug-related
clinical adverse events were less frequent in the raltegravir arm compared with
the efavirenz arm, at 54% vs 76%, respectively. | |
| Overall,
the most common adverse events, reported by more than 10% of participants, were
nausea, dizziness, and headache, which occurred with similar frequency in the
2 arms. | |
| Neuropsychiatric
adverse events were less frequent in the raltegravir compared with the efavirenz
arm (35% vs 61%). | |
| Laboratory
adverse events were uncommon in both treatment groups. | |
| Raltegravir
had a minimal effect on total cholesterol, LDL ("bad") cholesterol,
and triglyceride levels. |
Based
on these findings, the researchers concluded," In ART-naive patients, raltegravir
with [tenofovir/lamivudine] had potent and durable antiretroviral activity, which
was similar to [efavirenz/tenofovir/lamivudine] and was sustained to week 144." "Raltegravir
was generally well tolerated, they added. "[D]rug related adverse events
were less frequent in patients treated with raltegravir compared to efavirenz." These
data indicate that raltegravir continues to be effective at 144 weeks, consistent
with previously reported 48-week data. The U.S. Food and Drug Administration approved
raltegravir for treatment-naive HIV patients earlier this month. Hospital
Nacionale Cayetano Heredia, Lima, Peru; Merck Research Laboratories, West Point,
PA; Aaron Diamond AIDS Research Center, New York, NY; Hospital Nacionale Edgardo
Rebagliati, Lima, Peru; Siriraj Hospital, Bangkok, Thailand; Canadian Immunodeficiency
Research Collaborative, Toronto, Canada; Fundación Santafe de Bogota University
Hospital, Bogota, Colombia; Clinical Research Puerto Rico, Inc., San Juan, Puerto
Rico; Beth Israel Deaconess Medical Center, Boston, MA. 7/21/09 Reference
E
Gotuzzo, BY Nguyen, M Markowitz, and others. Sustained antiretroviral efficacy
of raltegravir as part of combination ART in treatment-naive HIV-1 infected patients:
144-week data. 5th International AIDS Society Conference on HIV Pathogenesis,
Treatment, and Prevention. Cape Town, South Africa. July 19-22, 2009. Abstract
MOPEB030.
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