December 22, 2008 — A multiple sclerosis patient treated with natalizumab (Tysabri, Biogen Idec/Élan) monotherapy who contracted progressive multifocal leukoencephalopathy (PML) earlier this year has died, the companies report. The patient, who died December 19 and had been diagnosed in October of this year, was in the United States.
Another 3 patients diagnosed with PML since reintroduction of natalizumab in 2006, including 1 announced just last week, were in Europe.
"The patient has died, and our thoughts and prayers go out to the family," Shannon Altimari, manager of public affairs for Biogen Idec, in Cambridge, Massachusetts, told Medscape Neurology & Neurosurgery.
Four Cases to Date:
On December 11, Biogen Idec and Élan reported to the United States Securities and Exchange Commission (SEC) that "relevant regulatory agencies" had been informed of another case of PML with natalizumab monotherapy in a patient with multiple sclerosis. The companies released information on their Form 8-K report to the SEC on December 15.
The case was found through surveillance, the companies noted, and the patient was stable at that time. The male patient is from Germany and had been on natalizumab monotherapy for 26 months.
The new case last week brought to 4 the number of cases that have been reported since natalizumab was reintroduced to the market in 2006; it had been withdrawn in 2005 when 3 patients developed PML during clinical trials. The drug was reintroduced with restricted distribution and risk-management programs, Tysabri Outreach: Unified Commitment to Health (TOUCH) in the United States and Tysabri Global Observational Program in Safety (TYGRIS) for the global cohort.
The newest case was found through TYGRIS. The diagnosis was made based on detection of JC virus (JCV) DNA in the cerebrospinal fluid (CSF) along with clinical signs, symptoms, and MRI findings consistent with PML, the SEC filing notes.
Cases 1 and 2 have both stabilized from their acute episode of PML and currently have "undetectable levels of JC virus in their CSF," Biogen Idec spokesperson Altimari told Medscape Neurology & Neurosurgery last week. They are both in rehabilitation and under medical care.
"Patient 3, it's still too early in her diagnosis, but she's in the acute phases of management for PML," Altimari said last week. This is the patient who subsequently died.
The 4 cases have occurred in the context of 35,500 patients who are currently on therapy, she added, "and so we still consider it a rare event, and well within the rate that's implied in the label."