RESEARCH NEWS New Drug Shows Promise in MG and Other Autoimmune Disorders

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The drug mycophenolate mofetil (CellCept), marketed by Roche Pharmaceuticals to prevent organ transplant rejection, has shown marked benefit in myasthenia gravis (MG) and may help in other disorders in which the immune system attacks the body's own tissues (autoimmune diseases).

Two studies at MDA clinics, one at Duke University in Durham, N.C., and the other at Johns Hopkins University in Baltimore, showed the drug was beneficial to people with MG, both alone and in combination with other medications. The advantage of the new drug may be that, while other drugs used in MG to suppress the immune system often have many, sometimes serious side effects, minimal side effects were found with mycophenolate mofetil.

In many cases, mycophenolate mofetil allowed patients to reduce their dosages of corticosteroids (the prednisone family of drugs). Such dosage reductions are important to minimize the side effects of corticosteroids, such as weight gain, fluid retention, bone loss, high blood pressure and psychological disturbances.

MG results from a mistaken attack by the immune system on acetylcholine receptors, specialized docking sites on muscle cells that receive signals from nerves. It causes fluctuating weakness.

Mycophenolate mofetil works by preventing T and B cells, key cells of the immune system, from replicating themselves by blocking a biochemical pathway that they need to do so. Other cells have an alternate replication pathway, so they're unaffected by the drug.

Drawbacks to mycophenolate include a long lag time before it begins to work -- sometimes as long as a year -- and high cost, estimated at about $480 a month. Third-party payers sometimes cover the cost but may require a doctor's letter explaining why it's needed.

Both papers are published in the Jan. 9 issue of Neurology. One study included 32 people with MG, of whom 22 improved on mycophenolate mofetil; the other included 12 people with MG, of whom eight improved.

PubMed links: [PubMed abstract, Duke] [PubMed abstract, Johns Hopkins]