CMS request for public comment:
National Coverage Policy for VNS therapy in
patients with treatment resistant depression.


I have been working with the Vagal Nerve
Stimulator now for over five years since I was a
co-investigator (with Dr. Barry Rittberg as
principal investigator) in the Cyberonics D02 and
D04 studies. Our site at the University Of
Minnesota enrolled 16 subjects and of those 16 we
did have several that did not respond to the
device in terms of their depression. However, the
majority the subjects enrolled did benefit to some
degree from the device and we had three or four
subjects that had markedly favorable response to
the point that several of them are off
antidepressant medications altogether.

I have been doing clinical trials in the area of
depression and anxiety for about 10 years and as
such very experienced in the design of clinical
trials. In terms of the D02 study there were, in
retrospect, problems with the study design. The
average patient in the trial had been depressed
for about 25 years; it appears that this may have
been too long of a period of time to expect
improvement using the device. I also think the
individuals with significant personality disorders
ended up being enrolled. Also it was clear the
trial was simply too short to demonstrate
separation from the placebo condition (device off
for 10 weeks during the D-02). In looking at the
data from the longer term study it is apparent
that the benefits for the device improve over at
least a one year period. The short term D02 study
would not capture this affect although the
difference in active treatment were demonstrated
in the comparative trial with D04 subjects.

Since FDA approval last summer I have worked with
about a dozen patients that have had the device
implanted and so far the majority of them are
having gratifying results in terms of the affect
on their depression. Also the device has been
well tolerated and the voice changes commonly seen
with the stimulation have been acceptable to the
patients.

In summary treatment resistant depression is a
significant and costly problem. A minority of our
depressed patients simply do not respond to our
usual intervention. Therefore it is important to
have an additional intervention available to these
patients. From a clinical perspective the VNS
appears to be a beneficial device and I expect
that the longer term registration trials will
demonstrate this. I the meantime, I think that we
need to able to offer selected patients this
promising intervention.