Two more Tysabri patients develop brain disease, Biogen Idec says
Biogen Idec Inc. said two more patients taking its promising multiple sclerosis drug Tysabri appear to have contracted a rare and potentially fatal brain disease, the first cases since the Cambridge biotech company reintroduced the treatment two years ago.
Biogen Idec originally launched Tysabri in late 2004, but yanked it off the market a few months after several patients were diagnosed with a serious brain disease, called progressive multifocal leukoencephalopathy, or PML. Two of the three patients who contracted PML eventually died.
In July 2006, the company reintroduced Tysabri with strict prescribing guidelines — designed to reduce the risk of the disease — and prominent warnings that PML could be a possible side-effect. The US label says one in 1,000 patients could potentially contract the disease.
Biogen Idec spokesman Tim Hunt said the company only confirmed the first case Wednesday and found out about the second yesterday. The first patient, who has been using Tysabri for 17 months, is clinically stable and at home. The second, who has been using Tysasbri for 14 months, is hospitalized.
But the company still contends the drug is so powerful that it is worth the risk for many MS patients who can’t be effectively treated with other drugs.
‘‘We believe Tysabri has established a new level of efficacy,’’ Hunt said. ‘‘It has offered new hope for many patients with MS.’’
Still, company shares were down 21 percent last night after hours on concern that the latest news could spook discourage doctors and patients from using the drug. Even worse, Biogen Idec could be forced to pull the drug from the market again if more cases of the disease show up — eliminating one of the company’s most important revenue sources. Nearly 32,000 patients worldwide, including 17,800 in the United States, now use Tysabri, and Biogen Idec has predicted it will attract 100,000 patients by 2010.
Deutsche Bank analyst Mark Schoenebaum wrote in a note to investors that he expects the stock to open sharply lower tomorrow, but would still advise against buying the stock right away because ‘‘investor sentiment could continue to weaken.’’
News of the additional PML cases comes just days after Biogen Idec impressed investors with strong growth for the drug. In the first six months of the year, the company said, it reaped nearly $262 million from Tysabri, tripling sales of the drug compared with the same period a year ago. In the latest quarter, more than a fifth of the company’s revenue came from Tysabri. Biogen Idec shares rights to the drug with Elan Corp. of Ireland.
Jim Mullen, the company’s chief executive, has said concerns about Tysabri were the key reason why Biogen Idec didn’t receive a single offer from a pharmaceuticals company when it briefly put itself on the market late last year, after prodding from billionaire investor Carl Icahn. Mullen said Tysabri was thought by some to be just too big a risk.
But 13,900 patients have been using the treatment for at least a year, including 6,600 who have been on the therapy for 18 months or longer, raising hopes that PML cases will not be common.
And Biogen Idec also notes that some other widely-used drugs are also associated with the brain disease. For instance, another Biogen Idec drug, Rituxan, used to treat non-Hodgkin’s lymphoma and rheumatoid arthritis, also carries a PML warning on its label. Genzyme Corp.’s cancer drug Campath has also been linked to PML. But the concern is especially strong about Tysabri because two patients died when the drug was new and still in limited use.
Todd Wallack can be reached at twallack@globe.com.
