Programme Supplement [International Conference on AIDS (16th: 2006: Toronto, Canada)]

Late Breaker Abstracts

Results: 136 subjects were randomized (83 LPV/r; 53 LPV/r+AZT/
3TC), Baseline characteristics were similar: VL (median 4.5 log
LPV/r; 4.3 log LPV/r+AZT/3TC), CD4 (median 235 LPV/r; 224 LPV/
r+AZT/3TC). Discontinuations through W48 were 19% for LPV/r
arm and 30% for LPV/r+AZT/3TC arm.

LPV r n (%) LPV/r n (%) LPV/r+AZT/
IT tiscont. Ontreatment 3TC n (%)
=failure VL available ITI Discont.
=failure

LPV/r+AZT/
3TC n (%) On
treatment VL
available

(1) VL <400
c/mL at W24
(2) VL <50
c/mL at W48
Primary
endpoint
(1)+(2)

65/82 (79%) 65/73 (89%) 41/53 (77%) 41/42 (98%)
58/82 (71%) 56/67t (84%) 40/53 (75%) 40/41t (98%)
53/81 (65%) 53/66$ (80%) 40/53 (75%) 40/411 (98%)

t p= 0.03, tp=0.02
Sub-optimal virological response occurred in 9 (11%) for LPVr
and 7 (13%) for LPV/r+AZT/3TC. At W48, median CD4 increase
from baseline was 152 for LPV/r, 159 for LPV/r+AZT/3TC. Through
Wk 48, 2/83 (2%) subjects on LPV/r monotherapy developed
resistance mutations (both in protease), versus 1/53 (2%) on LPV/
r+AZT/3TC (M184V). Similar tolerance was observed.M
Conclusions: Initiating antiretroviral therapy with LPV/r
monotherapy demonstrated a sustained virological efficacy.
However LPV/r monotherapy was associated with more episodes
of viremia compared with 3-drug therapy.
THLBO203
Lopinavir/ritonavir as single-drug maintenance therapy
in patients with HIV-1 viral suppression: forty eight week
results of a randomized, controlled, open label, clinical trial
(OK04 Study)
J. Arribas', F. Pulido2, R. Delgado3, E. Cabrero4, C. Cepeda2, J.
Gonzalez-Garcia', M.J. Perez-Elias', A. Arranz6, J. Portilla', J.
Pasquau8, J.A. Iribarren', R. Rubio2, A. Ocampo"o, P. Miralles0,
H. Knobell2, F. Gaya13, R. Munoz1, M. Norton4, OK04 Study
Group. 'Hospital La Paz, HIV Unit, Madrid, Spain, 2Hospital Doce
de Octubre, HIV Unit, Madrid, Spain, 3Hospital Doce de Octubre,
Laboratory of Molecular Microbiology, Madrid, Spain, 4Abbott,
Virology. Medical Dpt., Madrid, Spain, 5Hospital Ram6n y Cajal,
HIV Unit, Madrid, Spain, 'Hospital Principe de Asturias, HIV Unit,
Alcala de Henares, Spain, 'Hospital General de Alicante, HIV Unit,
Alicante, Spain, 8Hospital Virgen de las Nieves, HIV Unit, Granada,
Spain, 9Hospital de Donostia, HIV Unit, San Sebastian, Spain,
"oHospital Xeral Cies, HIV Unit, Vigo, Spain, "Hospital Gregorio
Marafi6n, HIV Unit, Madrid, Spain, 12Hospital del Mar, HIV Unit,
Barcelona, Spain, 1"Hospital La Paz, Investigation Unit, Madrid,
Spain, 14Abbott, Antivirals. GPRD, Abbot Park. IL, United States
Background: In patients with suppressed HIV replication on
lopinavir/ritonavir (LPV/r) and two nucleosides, this study compared
continuation of triple therapy (T) vs. LPV/r monotherapy (MT)
followed by reinduction with two nucleosides if virological rebound
occurred [without major protease inhibitor (PI) mutations].
Methods: Patients were eligible for this non-inferiority trial (upper
limit of 95% CI for T-MT <12%) if they had no history of virological
failure while receiving a PI and were receiving 2 nucleosides + LPV/
r with serum HIV RNA <50 c/mL for >6 months. Primary endpoint
was percent of patients without therapeutic failure, defined as
confirmed HIV RNA >500 c/mL with exclusion of MT patients who
re-suppressed to <50 c/mL after resuming baseline nucleosides,
or loss to follow-up, or change of randomized therapy other than
reinduction.
Results: 198 patients were randomised to the MT (n=100) or T
(n=98) arms. Baseline characteristics were similar in both arms.
After 48 weeks, percentage of patients without therapeutic
failure: 94% (MT) vs 90% (T) (T-MT= - 4%; upper limit 95%CI:
3.4%). Percentage of patients with HIV RNA <50/500 c/mL at 48
weeks (ITT, M = F, Reinduction = F): 85/89% (MT) vs 90/90%
(T) (p=0.4/0.99). Therapeutic failures: 6/100 in MT (3 lost to
follow-up, 2 confirmed rebound with PI resistance, 1 treatment
change) and 10/98 in T [4 lost to follow up, 3 confirmed rebound

(2 without and 1 with PI resistance), 3 adverse events]. 4 patients
with confirmed rebound after MT were reinduced and remain with
HIV RNA <50 c/mL.
Conclusions: In this trial, 48 weeks of LPV/r MT was non-inferior
to continuation of T in patients with prior stable suppression. The
majority of MT patients maintained HIV RNA < 50 c/ml without
reinduction.
THLBO204
A prospective, randomized, phase III trial of NRTI-, PI-,
and NNRTI-sparing regimens for initial treatment of HIV-1
infection - ACTG 5142
S.A. Riddler, R. Haubrich2, G. DiRienzo3, L. Peeples3, W.G.
Powderly4, K.L. Klingman5, K.W. Garren6, T. George', J.F. Rooney8,
B. Brizz', D. Havlir"o, J.W. Mellors', AIDS Clinical Trials Group 5142
Study Team. 'University of Pittsburgh, Pittsburgh, United States,
2University of California San Diego, San Diego, United States,
3Harvard School of Public Health, Statistical and Data Analysis
Center, Boston, United States, 4University College, Dublin, Ireland,
5NIAID, Division of AIDS, Bethesda, Maryland, United States,
'Abbott Laboratories, Abbott Park, llinois, United States, 'BristolMyers Squibb, Plainsboro, New Jersey, United States, 'Gilead
Sciences, Foster City, California, United States, 'Social & Scientific
Systems, Inc, Silver Spring, Maryland, United States, "oUniversity
of California San Francisco, San Francisco, United States
Background: First-line therapy with 2 nucleoside reverse
transcriptase inhibitors (2NRTI) and either efavirenz (EFV) or
lopinavir/ritonavir (LPV) has not been compared in a randomized
trial; and the NRTI-sparing combination of LPV+EFV has not been
studied as initial therapy.
Methods: Randomized, open-label, prospective trial comparing
three class-sparing regimens for naive subjects: LPV+EFV (L/E)
vs. LPV+2NRTI (LPV; soft-gel BID) vs. EFV+2NRTI (EFV). NRTIs
were selected before randomization from ZDV, d4T XR or TDF
(each plus 3TC). Primary objectives were to compare between
arms the time to confirmed virologic failure (VF; HIV-1 RNA>200
after week 32) and regimen completion (RC; VF or toxicity-related
discontinuation of any regimen component). The significance
level adjusted for multiple between-arm comparisons and interim
analyses was 0.016. Analyses were ITT (censored data not equal
to failure).
Results: 753 enrolled subjects (median CD4 182 cells/mm3,
median HIV-1 RNA 100,000 copies/mL) were followed for a median
112 weeks. NRTI choice was ZDV 42%, d4T XR 24%, and TDF 34%.
No statistically significant between-arm differences were observed
in time to VF or RC (p>0.016). However, there was a trend toward
shorter time to VF (p=0.033) and RC (p=0.065) for LPV compared
with EFV. Kaplan-Meier estimates of the proportions without VF
by week 96 were 73%, 67% and 75% for L/E, LPV and EFV arms,
respectively. At week 96, the percentages with HIV-1 RNA <50
copies/mL were 83%, 77%, and 89% for the L/E, LPV and EFV
arms, respectively (p=0.003 LPV vs. EFV). The median 96 week
increase in CD4 was significantly greater for LPV-containing arms
(L/E +268, LPV +285 cells/mm3) than for EFV (+239.5; p=0.01).
The time to treatment-limiting toxicity was similar for all arms.
Conclusions: Compared with a regimen of EFV+2NRTI,
LPV+2NRTI tended to have shorter time to virologic failure and
regimen completion. The NRTI-sparing regimen of LPV+EFV had
similar efficacy and safety as EFV+2NRTI.
THLBO205
The KLEAN Study: fosamprenavir + ritonavir (FPV/r) versus
Iopinavir/ritonavir (LPV/r) in antiretroviral-nalve (ARTNaive) HIV-1 infected adults over 48 weeks
J. Eron', P. Yeni2, J. Gathe, Jr.', V. Estrada', E. DeJesus', S.
Staszewski6, P. Lackey', L. Yau', D. Sutherland-Phillips', P.
Wannamaker, M. Shaefer'. 'University of North Carolina at Chapel
Hill, Chapel Hill, United States, 'Hopital Bichat, Paris, France,

'Therapeutic Concepts, PA, Houston, United States, 'Hospital
Clinico San Carlos, Madrid, Spain, 'Orlando Immunology Center,

Late Breaker
Abstracts

Programme
Contributors
Index

XVI INTERNATIONAL AIDS CONFERENCE * 13-18 AUGUST 2006 * TORONTO CANADA * PROGRAMME SUPPLEMENT