Tysabri Brain Infection Disclosure Policy Modified
According to a Wall Street Journal report, Biogen will converse with doctors once a month on the occurrence of new cases of a rare brain infection in patients using its multiple sclerosis treatment Tysabri. The situation is closely watched because Tysabri, a highly effective treatment sold with Elan Corp. was previously pulled from the market because of its association with progressive multifocal leukoencephalopathy (PML), a debilitating and often fatal condition.
Since, Tysabri reentered the U.S. market in 2008, Biogen and regulators have struggled with how to provide information on PML because case-by-case updates of a specific side effect are unprecedented. Last summer, the company stopped providing updates altogether. As of mid-January, the number of cases stands at 31, which puts the overall incidence rate at about 1-in-1,000 patients, as implied by the drug’s label.
Under the new plan, Biogen will proactively update doctors midmonth and provide information through a password-protected Web site. It will include the number of PML cases, with an incidence rate broken down by duration of use, as well as a cumulative patient exposure figure, which is different than the quarterly patient count provided to investors.
Biogen withdrew the drug from the market for 18 months beginning in 2005 after three patients developed PML. Infections re-emerged in 2008, and Biogen provided regular weekly updates to the public until last July, when it officially stopped providing any information.
In October, European and U.S. regulators said the number of PML cases had risen to 24, well above Biogen’s July disclosure of 11, surprising Wall Street and raising questions about Biogen’s disclosure policies and refusal to comment on PML case numbers. The company began to re-think its approach at about the same time.
On January 21, 2010, the European Medicines Agency’s Committee for Medicinal Products for Human Use, known as CHMP, recommended increased risk-mitigation measures for Tysabri after reviewing its safety. The panel concluded that Tysabri’s benefit for MS patients outweighs its risks and the drug should stay on the market.
Tysabri had more than $1 billion in 2009 sales.
