Reports of a rare and deadly neurological condition called progressive multifocal leukoencephalopathy (PML) in patients taking certain biologic immunosuppressants for autoimmune or inflammatory conditions are raising concerns about the safety of these drugs.
In February, the US Food and Drug Administration (FDA) issued a public health advisory alerting physicians and patients to 1 possible and 3 confirmed cases of PML in patients taking efalizumab, a once-weekly injection approved for the treatment of severe plaque psoriasis in adults. The label of this drug had been changed to reflect the risk of serious infections, including PML, in October 2008.
Kuehn BM. Rare Neurological Condition Linked to Newer Monoclonal Antibody Biologics. JAMA. 2009;301(14):1423-1424. doi:10.1001/jama.2009.451