SOLO: 48-week efficacy and safety comparison of once-daily fosamprenavir /ritonavir versus twice-daily nelfinavir in naive HIV-1-infected patients.
OBJECTIVE
To compare the magnitude and durability of the antiviral response to fosamprenavir (FPV) plus ritonavir (RTV) once-daily (FPV/r QD) with nelfinavir twice-daily (NFV BID), each administered with abacavir and lamivudine twice-daily.


METHODS
An international, phase III, randomized, open-label study in antiretroviral therapy-naive, HIV-infected adults.


RESULTS
Patients with advanced HIV disease received FPV/r QD (n = 322) or NFV BID (n = 327). At week 48, 69% of patients in the FPV/r QD group and 68% in the NFV BID group had plasma HIV-1 RNA (vRNA) < 400 copies/ml, whereas 55% of patients in the FPV/r QD group and 53% in the NFV BID group had vRNA < 50 copies/ml (intent to treat, rebound/discontinuation = failure). More patients in the NFV BID group (17%) experienced virological failure than in the FPV/r QD group (7%). Efficacy of FPV/r QD was maintained in patients with CD4+ cell counts < 50 x 10 cells/l or vRNA >/= 100 000 copies/ml at entry. At week 48, median CD4+ cell counts were increased to 203 x 10 cells/l (FPV/r QD group) and 207 x 10 cells/l (NFV BID group). Both regimens were generally well tolerated. Diarrhea was more common on NFV BID than on FPV/r QD (16 versus 9%; P = 0.008). Fasting lipid profile results were generally favorable in both treatment arms. FPV/r QD maintained plasma amprenavir (APV) trough concentrations above the mean phenotypic drug-susceptibility (IC50) for wild-type virus for APV.


CONCLUSIONS
As a first choice protease inhibitor with a low daily pill burden, FPV/r QD was well tolerated and provided potent, durable antiviral suppression.
Gathe
Joseph C
JC
Therapeutic Concepts, P.A., Houston, Texas, USA.
Ive
Prudence
P
Wood
Robin
R
Schürmann
Dirk
D
Bellos
Nicholaos C
NC
DeJesus
Edwin
E
Gladysz
Andrzej
A
Garris
Cindy
C
Yeo
Jane
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D002219:Carbamates; D005260:Female; D005663:Furans; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D019888:Nelfinavir / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D010755:Organophosphates / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D010349:Patient Compliance; D019438:Ritonavir / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics
D002219:Carbamates; D005663:Furans; D017320:HIV Protease Inhibitors; D010755:Organophosphates; D013449:Sulfonamides; D019888:Nelfinavir; D019438:Ritonavir; C426859:fosamprenavir