How Low Does Your Viral Load Have To Be: Kaletra plus d4T/3TC study
Reported by Jules Levin
At the post 9/11 ICAAC (Dec 2001), researchers reported results from this
study in which patients who achieved <3 copies/ml between weeks 24-72 after
starting therapy did not affect the maintenance of <400 or <50 copies/ml
after 144 weeks of Kaletra combination therapy. At Glasgow Perrin and Abbott
reported the same findings after following patients for 204 weeks (4 years).
These results apply to Kaletra plus d4T/3TC but may or may not apply to other
In other words, the Glasgow study found there was no greater risk of loss of
viral control through 204 weeks of follow-up in patients who did not achieve
¾3 copies/ml during the first 24-72 weeks of therapy in this study compared
to patients who did achieve ¾3 copies/ml during the first 72 weeks. Here is
the link to my original article from ICAAC 2001 on this study:
Failure to Achieve HIV RNA <3 copies/mL by Week 72 Is Not Associated with
Loss of Virologic Response Through 144 weeks of Lopinavir/Ritonavir-Based
Here are conclusions study authors presented in Glasgow:
Based on the ITT NC=F analysis through Week 204, 71% and 70% of patients had
HIV RNA <400 copies/mL (on-treatment analysis 99%) or <50 copies/mL
(on-treatment analysis 97%) at Week 204.
--Mean increase from baseline to Week 204 in CD4 cell count was +440 cells/mm
--15 patients met loss of virologic response criteria.
7/15 remained on study through 204 weeks, and 7/7 had HIV RNA <50 at Week 204.
8/15 patients discontinued. 1 patient discontinued at Week 4 without
achieving HIV RNA <400 copies/mL, 1 patient discontinued with HIV RNA
resuppressed <400 copies/mL at final visit, and 6 patients discontinued after
rebound (2 lost to follow-up, 4 due to noncompliance).
-Genotype was available on 10 patients, including all 8 who discontinued
after loss of virologic response. Isolates from 0/10 patients demonstrated
resistance in protease, and 3/10 demonstrated 3TC resistance.
--28 patients discontinued prior to Week 204, including 7 due to adverse
events probably or possibly related to LPV/r. Diarrhea and nausea were the
most common adverse events, and lipid elevations were the most common
100 antiretroviral naive patients entered this phase II study and as said
just above 28 discontinued.
Glasgow abstract concluded:
--Whether one does or does not achievend/or sustain HIV RNA <3 copies/mL
through the first 1.5 years of LPV/r therapy does not appear to predict risk
of virologic failure at either <50 or <400 copies/mL through an additional
2.5 years of follow-up.
--Intermittent viremia >3 copies/mL may be due to assay variability,
variation in adherence patterns, or other physiologic factors such as the
presence of subacute
intercurrent illness. The inability to suppress viral load to <3 copies/mL
may be due to the aforementioned factors as well as the potential impact of
the size of the reservoir
of latently infected cells or the status of the immune system.
--These observations may differ depending on the potency, tolerability and
genetic barrier of the antiretroviral regimen being evaluated.
--Among patients with high BL VL (>100,000 copies/mL) or low BL CD4 count
3), virologic response through Week 204 was similar to that for patients with
less advanced disease.
--A longer duration of follow-up is necessary to determine whether any of
these virologic or immunologic factors will eventually have an impact on the
duration of virologic response.