Two Cancer Drugs Get FDA Black Box Warning Due to Hepatitis B LinkSep 26, 2013
The U.S. Food and Drug Administration (FDA) has increased the warnings on two blood cancer medications over the drugs’ ties to the hepatitis B virus in some patients.
The blood cancer drugs — GlaxoSmithKline Plc's Arzerra (ofatumumab) and Rituxan (rituximab), made by Roche Holding AG and Biogen Idec Inc. — may increase risks for immunosuppression-related reactivation of the hepatitis B virus in patients who were previously infected with the virus, according to Reuters. The increased risks warranted a so-called “Black Box” warning, the agency’s most stringent warning.
Arzerra received United States approval in 2009 for the treatment of chronic lymphocytic leukemia (CLL). Rituxan received approval for the treatment of a number of conditions, including CLL, non-Hodgkin's Lymphoma, vasculitis, and rheumatoid arthritis, Reuters reported. Both drugs are anti-CD20-directed monoclonal antibodies, according to MedPageToday.
The drugs suppress the body's immune system. Because the immune system is needed to fight infections, hepatitis B, a serious liver infection, can become chronic when reactivated, which can lead to liver failure, liver cancer, or cirrhosis of the liver, Reuters reported. Hepatitis B, which also can cause permanent scarring of the liver, is spread through contact with infected blood and bodily fluids.
Hepatitis virus reactivation can take place in people who were previously infected, even if the hepatitis B infection had been clinically resolved, MedPageToday explained. If the hepatitis B virus (HBV) remains latent in a person’s hepatic tissue and that individual is later immunosuppressed, the disease can reactivate — and possibly lead to liver failure and death.
To date, more than 100 potential cases of fatal HBV-associated hepatic injury tied to Rituxan and Arzerra have been identified in the FDA's Adverse Event Reporting System (FAERS) database, according to MedPageToday. Of 109 reported cases of hepatitis B-associated injury with the drugs, 106 cases involved rituximab and three involved Arzerra.
Although the risk of HPV reactivation associated with Arzerra and Rituxan is described in the “Warnings and Precautions” section of each drug’s label, the FDA stated that reactivation cases, some fatal, continue to take place. Now, this information will be included on the Black Box, Reuters explained.
The agency recommends physicians screen all of their patients for the hepatitis B virus before starting them on either medication, and that they also monitor those patients who reveal evidence of prior infection for indications of the virus’s reactivation; monitoring should continue for months after therapy has discontinued, according to MedPageToday.
Reactivation following exposure to the anti-CD20 monoclonal antibody generally occurs anywhere from 63 days after the first dose, to up to one year after the last dose, MedPageToday wrote.