FDA strengthens warning on Arzerra, Rituxan over hepatitis B reactivation
The FDA on Wednesday issued new boxed warnings for GlaxoSmithKline’s Arzerra (ofatumumab) and Roche and Biogen Idec’s Rituxan (rituximab) concerning a risk of reactivation of the hepatitis B virus (HBV) in previously infected patients. The updated labels for the cancer drugs will also include additional recommendations for screening, monitoring and managing patients to decrease the risk of HBV reactivation.
The US regulator noted that the risk of HBV reactivation is already described in the warnings and precautions section of the labels for both products, which act to suppress the body’s immune system. However, the continued occurrence of HBV reactivation among patients using these drugs prompted the regulator «to examine this risk further for current evidence that may aid in recognition and reduction in the risk." Consequently, the boxed warning on the labeling of Rituxan was updated to reflect the risk of HBV reactivation, while a new boxed warning was created for Arzerra label regarding the risk. The FDA added that the warnings and precautions sections of the drugs' labels will also be revised to state new recommendations.
Specifically, the drug regulator is recommending that doctors screen all patients for HBV infection prior to initiating treatment with Arzerra or Rituxan. The agency also mentioned that patients with evidence of prior HBV infection should be monitored for clinical and laboratory signs of hepatitis B or HBV reactivation during treatment with these drugs and for several months after treatment discontinuation, as reactivation of the virus can occur several months after treatment.