Switching
from Other Ritonavir-boosted Protease Inhibitors to Boosted Atazanavir (Reyataz)
Did Not Improve Body Fat Accumulation: REAL Study  | Reyataz
Capsule | | Kaletra
Tablet |
Atazanavir
(Reyataz) is a potent, well-tolerated, once-daily protease inhibitor (PI)
that has been extensively studied in both treatment-naive and treatment-experienced
patients. Comparative data have demonstrated efficacy similar to that of lopinavir/ritonavir
(Kaletra), but with a superior lipid profile. At
the XVII International AIDS Conference this month in Mexico
City, Graeme Moyle of Chelsea and Westminster Hospital in London presented
48-week results from the REAL study, which evaluated the impact on body composition
of switching from any twice-daily ritonavir-boosted
PI to once-daily atazanavir/ritonavir
regimen in patients with lipohypertrophy
(fat accumulation). In
this prospective, multicenter, open-label, randomized study, patients with waist
circumference > 90 cm and viral load < 400 copies/mL were randomized (2:1)
to either switch to atazanavir/ritonavir
or continue on their current boosted PI. A total of 200 patients were randomized
and treated: 131 in the atazanavir/ritonavir arm, 69 in the continuing PI/ritonavir
arm (including 72% on lopinavir/ritonavir).
Computed
tomography was used to quantify visceral adipose tissue (VAT), subcutaneous adipose
tissue (SAT), and total adipose tissue (TAT); DEXA was used to assess trunk and
limb fat. The primary endpoint was changes in trunk-to-limb fat ratio by DEXA
at 48 weeks. Results •
At
week 48, there was no significant difference between regimens in mean percent
change from baseline in trunk-to-limb fat ratio or in mean change from baseline
in VAT, SAT, TAT, VAT-to-TAT or VAT-to-SAT.
•
Virological
rebound rates were similar in the 2 arms.
•
There
was no loss of virological suppression after switching to atazanavir/ritonavir
(> 50 copies/mL in 5% of atazanavir/ritonavir arm vs 6% of continuing PI/ritonavir
arm).
•
Mean
changes in CD4 count from baseline CD4 were 15 cells/mm3 in the atazanavir/ritonavir
arm vs 44 cells/mm3 in the continuing PI/ritonavir arm.
•
Mean
percent changes from baseline in fasting lipids in the atazanavir/ritonavir vs
continuing PI/ritonavir arms were
•
Total cholesterol: -13% vs -1% (P < 0.0001);
•
HDL
("good") cholesterol: -6.2% vs -2.6% (P = 0.22);
•
LDL ("bad") cholesterol: -10.4% vs 2.6% (P = 0.0086);
•
Non-HDL cholesterol: -14.8% vs -0.6% (P < 0.0001).
•Triglycerides:
-23.8% vs -11.7% (P = 0.04);
•
Discontinuation
rates were 8% for atazanavir/ritonavir vs 10% for other PI/ritonavir.
•
Overall adverse events were comparable in both arms.
In
conclusion, the study authors wrote, "In this 48 week analysis, a switch
from [twice-daily] boosted PI to [once-daily] boosted atazanavir in patients experiencing
lipohypertrophy resulted in no significant change in body composition [trunk-to-limb
fat ratio] with maintenance of efficacy and significant reduction in [lipid parameters]
total cholesterol, LDL cholesterol and non-HDL cholesterol." They
added that the significant difference in change in total body fat is attributable
to the greater loss of limb fat in the continuing PI/ritonavir group. Follow-up
though 96 weeks is planned. Chelsea
And Westminster Hospital, London, UK; Saint-Antoine Hospital, Paris, France; Hosp.
Civil De Gdj, Mexico, Mexico; Diversified Medical Practices PA, Houston, TX; Medizinische
Klinik Der LMU, Munich, Germany; St.George's Hospital, London, UK; Hospital de
la Princesa, Madrid, Spain; Bristol-Myers Squibb Research and Development, Braine
L'Alleud, Belgium; Bristol-Myers Squibb Research and Development, Rueil-Malmaison,
France; Istituto Malattie Infettive I.R.C.C.S, Rome, Italy. 8/19/08 Reference Moyle
G, Girard J-M, Andrade J, and others. Continuation
of BID boosted PI vs switch to once-daily ATV/RTV for the management of lipodystrophy:
48 week primary analysis of the 96 week multicenter, open-label, randomized, prospective
REAL study. XVII International AIDS Conference (AIDS 2008). August 3-8, 2008.
Mexico City.
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