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Update Bulletin
January 22, 2001
The following provides information
about recent articles in the news media concerning multiple
sclerosis.
Toronto researchers probe immune system
'switches'
Toronto researchers reported finding an important "off
switch" that is probably involved in turning off immune
system attacks. The results of their work were reported in a
letter in the January 18 issue of the science journal Nature
and were covered widely by the news media.
Although initial media reports hailed this
protein called CD45 as the "Holy Grail" of the immune
system, a clarification issued by lead investigator Dr. Josef
Penninger, the Princess Margaret Hospital, said while the protein
is important it is one of about 140 such protein "on and
off switches". They tell hormones and proteins to turn
on and off the immune system attack on invading viruses or bacteria.
When the immune system fails to turn off, the result can be
diseases such as multiple sclerosis, diabetes and heart disease.
In the case of multiple sclerosis, immune system cells target
myelin, the protective covering of the central nervous system.
"While this work is still in its early
days, it may lead to treatments that target CD45 and other proteins
to turn off the immune system attack on myelin," said Dr.
William McIlroy, national medical advisor.
Possible Study of 'Cobra' Drug
Time magazine reported in its January 16, 2001 issue that a
drug derived from modified cobra venom might be tested at Canadian
MS clinics as a treatment for MS in the near future.
Immunokine has been tried in 25 people with
MS under non-placebo controlled conditions with initial encouraging
results. Phylomed, the Florida company that makes the drug,
has applied to Health Canada to test it at several Canadian
MS clinics. Additional details will be provided when they become
available.
The study of Immunokine was a Phase I
trial. This is a short study in which both the people receiving
the therapy and the study investigators know the participants
are receiving active treatment. The primary outcome is to test
for safety of the therapy.
The usual next step would be a Phase II
trial in which participants are divided into groups. One group
receives active treatment and one receives a placebo (non-active)
treatment. Neither the participants nor the physicians who examine
them know who is taking which treatment until the code is broken
at the end of the study. This is called a double-blind, placebo
controlled study. The investigators start to gather data on
whether the therapy actually works while still measuring safety.
If results from the Phase II study are positive,
the next stage is a Phase III trial. It is a double-blind,
placebo controlled study that involves a large number of people,
often at many research sites for a number of months. It collects
data on safety, the effectiveness of the therapy and side effects.
These data are necessary for any submission to Health Canada
for evaluation of a therapy for potential approval.
Prepared by National Communications and Social
Action Department
Disclaimer
The Multiple Sclerosis Society of Canada is an independent,
voluntary health agency and does not approve, endorse or recommend
any specific product or therapy but provides information to
assist individuals in making their own decisions.
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