At the AAN meeting
in April 2011, there were several important presentations on MS. The most interesting concerning new treatments
were on an intravenous treatment that seems to have excellent effectiveness, and two oral treatments.
The intravenous treatment
is a monoclonal antibody called ocrelizumab. This antibody depletes B cells, and is similar to rituximab,
which has already been tested in MS with promising results. Ocrelizumab was given every 24 weeks, and it
had a marked effect on MS activity on MRI scans, reducing new activity by more than 90%. Relapse
rate was also significantly decreased by about 80% compared to no treatment and more than 50% compared to Avonex.
This drug looks very promising, with excellent effectiveness, but safety is a concern. There was
one death in the 60 patients in the high dose group, but the relation to the treatment is not clear at present.
Ocrelizumab is now in phase III testing in both relapsing and progressive MS.
The first oral treatment
presented was teriflunomide. This drug depletes lymphocytes, both T and B cells, and a very similar drug
is already in use for rheumatoid arthritis. The relapse rate decreased about 31%, and the progression decreased
about 30%. Similar benefits were seen on MRI. Safety appeared good, but one concern
is adverse effects in pregnancy. The oral form and minimal side effects are attractive, but the effectiveness
is not any better than interferon or glatiramer. This may be a good agent to use in combination with another
treatment, and such studies are presently in progress.
The second oral drug was laquinimod.
This is an interesting treatment because it modulates the immune system, rather than suppressing it.
It should theoretically have less infectious complications. This was a large Phase III study with
550 patients on laquinomod, and 556 on placebo for two years. Relapse rate was reduced 23% and progression
of disability was reduced 36%. There were no concerning side effects. This treatment
is attractive because it is oral and relatively safe, but its effectiveness is less than existing treatments.
the scientific sessions, there is continuing progress in the genetics of MS. About 57 genes related
to MS susceptibility have been identified to date, with more to come. The majority with known function
are related to the immune system, supporting the idea that MS is an immune-mediated disease. Two
of them are related to Vitamin D metabolism, supporting a role for Vitamin D in MS.