Tysabri - Update on PML Risk and Recovery
Held in Montreal last week was the largest single gathering of MS clinicians and researchers at the World Congress on Treatment and Research in Multiple Sclerosis, the first ever joint meeting of ACTRIMS, ECTRIMS, and LACTRIMS.
I was interested to reading updates on the use of TYSABRI (natalizumab), especially for the two male MS patients in Europe (37-yr old Swede and 52-yr old German) who developed PML (an often fatal opportunistic brain infection) earlier this summer. There was much speculation at the time that access to Tysabri might become more limited.
From the relevant Abstract prepared for the Conference:
A 52-year old male who has had MS for 30 years, and during that time had various treatments including azathioprine for five years, began natalizumab treatment in May 2007 because of ongoing disease activity with relapses. In the following year, the patient remained stable until May 2008 when symptoms of depression and a mild left-sided partial paralysis appeared.
When these symptoms progressed despite treatment and atypical lesions in cranial MRI were noted, the patient was referred to the neurological department in July 2008 where another cranial MRI showed two enlarging lesions. CSF was examined twice, and JC-virus was detected. This patient was found to be severely immunosuppressed. After plasma exchange therapy (plasmapheresis), in combination with antiviral medication, the patient immediately stabilized with respect to mood and cognition.
From the Update presented at the Conference (source, Reuters):
Dr. Ralf Gold of Ruhr University Bochum, Germany, said in an interview that a German patient, hospitalized near the town of Freiburg, is close to a coma and being fed through tubes, though he is breathing on his own.
The other patient, a 37-year-old Swede, is in a rehabilitation center near Stockholm and suffering only from mild weakness on one side of his body.
Gold said the 52-year-old German patient was not diagnosed until at least three months after developing the disease, whereas the Swedish patient's condition was identified in less than a month. As a result, the German patient had a higher level of the virus in his brain.
Gold said the virus appears to be leaving the German patient's brain, but he is suffering from brain damage brought about by a condition known as immune reconstitution inflammatory syndrome, or IRIS. This occurs when the immune system, in eliminating an infection, produces an excessive inflammatory response that can worsen symptoms.
It is most likely the patient will be permanently brain damaged, Gold said. The only question is by how much. The patient was started on a course of corticosteroids on Friday, the standard treatment for IRIS. It typically becomes clear within a few days whether such a treatment is likely to work, Gold said. In the meantime, the patient is in a critical condition but not in intensive care.
What do you think of the PML risk associated with Tysabri?