The FDA issued an announcement on Jan. 13 that two additional cases of progressive multifocal leukoencephalopathy (PML) were reported with use of Adcetris (brentuximab vedotin). The FDA mandated that the lymphoma drug's label now include a Boxed Warning highlighting the risk, as well as a Contraindication against the use of Adcetris with bleomycin due to an increased risk of pulmonary toxicity.

Symptoms of the rare, but serious and potentially fatal brain infection, PML, include changes in mood or usual behavior, confusion, thinking problems, loss of memory, changes in vision, speech, or walking, and decreased strength or weakness on one side of the body. Patients are advised to contact their doctor immediately if symptoms are observed, and health care professionals are advised to hold Adcetris dosing if PML is suspected and discontinue if a diagnosis is confirmed, according to the FDA's alert.

Adcetris received FDA approval in August 2011 for treatment of Hodgkin lymphoma and systemic anaplastic large cell lymphoma (ALCL). It was the first new FDA-approved treatment for ALCL, and the first for Hodgkin lymphoma since 1977. At that time one case of PML had been reported and was described in the Warnings and Precautions section of the label.

Health care professionals are asked to report adverse events involving Adcetris to the FDA Medwatch program.