FDA calls for strictest warning on drug linked to brain infection

The US Food and Drug Administration plans to strengthen the warning label on lymphoma drug Adcetris over concerns that it may be linked to a rare, but deadly brain infection.

At the time of approval in August 2011, the regulator had seen one case of progressive multifocal leukoencephalopathy (PML) in a patient who had taken the drug, marketed by Seattle Genetics and Takeda Pharmaceutical. Since then, two more cases have been reported and the FDA is requiring a boxed warning – its strictest warning – to be placed on Adcetris’ label. The regulator has also warned that Adcetris should not be taken with cancer drug bleomycin due to increased risk of lung toxicity. Seattle Genetics must now conduct follow-up studies to confirm the safety of the treatment.

In 2011, Adcetris became the first drug to be approved by the FDA for the treatment of Hodgkins in 30 years. The drug also treats a rare disease known as systemic anaplastic large cell lymphoma.

Chief medical officer Thomas Reynolds said in a statement, “Although PML in lymphoma patients can be caused by factors such as underlying disease and prior therapies that affect the immune system, a contributory role of Adcetris cannot be excluded.”