A Randomized, Placebo-Controlled and
Double Blind Study at Stanford
University
Drs. Jose Montoya and Andreas Kogelnik of Stanford Hospital
Infectious Disease Clinic are planning a double blinded placebo
controlled clinical
trial to determine whether patients with Viral Induced CNS Dysfunction,
a subset of patients with Chronic Fatigue Syndrome, would benefit
from valganciclovir treatment.
The trial will enroll 30 patients
and is expected to start in the spring of 2007. The HHV-6 Foundation
has supported this group to
initiate
and design the trial and Roche Pharmaceuticals, the manufacturer
of valganciclovir,
has agreed to fund the study in full. This trial was precipitated
through a preliminary study conducted by Drs. Montoya and Kogelnik
announced at the 2006 HHV-6 & HHV-7 Conference in Barcelona
which reported the successful response to antiviral treatment
experienced by nine out of 12 (75%) of patients chronically
infected with human
herpes virus 6 (HHV-6) and Epstein-Barr virus (EBV) and who
were suffering
from debilitating fatigue for more than one year (median 3 years,
range 1 to 8 years). In these patients antibody titers dropped
four fold suggesting (a) these patients had active infections
(b) elevated
antibody levels can be a useful indicator of active infection
in some patients and (c) a subset of patients with CFS and elevated
antibody
levels to HHV-6 and EBV may have an illness that is caused by
reactivation
of these viruses, and that is responsive to valganciclovir therapy.
The
successful results as well as the limitations of the preliminary
study have warranted a larger, randomized controlled trial
with long-term follow-up to confirm the possible value of antiviral
therapy and exclude
a placebo effect. Additionally, the study aims to establish
a quantifiable biological marker in these patients that will
facilitate
the identification
of those likely to respond to valganciclovir and will make
it
possible to assess response to treatment. The planned study
will provide further
definition of this subset of patients, with better and more
standardized viral assays as well as immunologic, radiological, and
genetic endpoints to determine whether there are objective and measurable
changes
in these parameters and whether they correlate with clinical improvement.
Despite the fact that the improvements in physical activity and
cognitive functions were dramatic and impressive in the
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preliminary
group, they were self-reported and not objective measurements. The
planned study will utilize a more comprehensive evaluation of the
functional status of subjects, using established and validated instruments.
The resulting data from the trial will help to elucidate the possible
role of EBV, HHV-6 (or a yet to be known virus) and/or an altered
immune system as possible triggers for CFS.
The trial is now fully enrolled.
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