Raptiva PML Infection Warning Issued in Canada after Two Deaths in U.S.

Health Canada has released a letter sent to healthcare providers warning about an increased risk of serious infections, including Progressive Multifocal Leukoencephalopathy (PML), as a side effect of Raptiva. They disclosed that two deaths from PML have been reported in the United States among patients taking Raptiva for psoriasis.

Raptiva (efalizumab) is a psoriasis drug which was approved in the U.S. in 2003 and Canada in 2005. It generated worldwide sales of $120 million in 2007, and approximately 46,000 people have received the injection.

Psoriasis is a skin disease caused by over-activity of immune cells, called T-cells. This can lead to excess skin cells being produced and a build up in the form of plaques.

Raptiva is an injectable therapeutic antibody that suppresses T-cell activity, but side effects of Raptiva could increase the risk of serious infections due to weakening of the immune system.

Health Canada, which is the drug regulatory agency in Canada, released a letter sent to healthcare providers on December 22, 2008 warning about the increase risk of infections, including a serious and potentially fatal brain infection known as Progressive Multifocal Leukoencephalopathy (PML). The letter disclosed that two patients treated with Raptiva in the United States have died as a result of PML.

Progressive Multifocal Leukoencephalopathy is a rare viral infection that attacks the brain and central nervous system. There is no known cure and in many cases it results in death. Symptoms could include dizziness, loss of balance, confusion, difficulty walking, impaired speech and vision problems.

In the United States, the FDA announced on October 16, 2008 that a “black box” warning is being added to the Raptiva warning label about the risk of serious infections, including bacterial sepsis, viral meningitis, invasive fungal disease and Raptiva PML infections.

According to the letter released by Health Canada, the two Raptiva PML deaths in the United States involved patients who were 70 years old or older and had been receiving the drug continuously for about four years. One of the patients also received another immune system suppressing medication for a short time about three years before the diagnosis of PML.

A direct cause and effect relationship between Raptiva side effects and PML has not been established in the two cases, but it can not be ruled out according to EMD Serono Canada, Inc., which markets the drug in Canada.