News - Letter Warns of Hepatitis B Reactivation Associated with Anti-TNF alpha Products

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Letter Warns of Hepatitis B Reactivation Associated with Anti-TNF

alpha Products

OTTAWA, CANADA -- January 18, 2006 -- Amgen Canada, Abbott

Laboratories, and Schering Canada have sent out a letter to health

care professionals in consultation with Health Canada regarding their

anti-TNF alpha products Enbrel (etanercept), Humira (adalimumab), and

Remicade (infliximab).

The focus of the letter is updated safety information regarding the

anti-TNF alpha therapies Enbrel (etanercept), Humira (adalimumab),

and Remicade (infliximab), which are authorized for sale in Canada.

Enbrel (etanercept, Immunex Corporation, Distributor: Amgen Canada,

Inc.) is approved for treatment of rheumatoid arthritis, juvenile

rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis,

chronic plaque psoriasis.

Humira (adalimumab, Abbott Laboratories, Ltd.) is approved for

treatment of rheumatoid arthritis,

Remicade (infliximab, Centocor, Inc., Distributor: Schering Canada,

Inc.) is approved for treatment of rheumatoid arthritis, crohn's

disease, and ankylosing spondylitis.

Based on review of recent post-marketing reports:

Hepatitis B virus (HBV) reactivation has been reported very rarely in

patients with chronic hepatitis B infection receiving the anti-TNF

alpha agents Enbrel, Humira, and Remicade, the letter states.

Patients at risk for HBV infection should be evaluated for prior

evidence of HBV infection before initiating anti-TNF alpha therapy.

Those identified as chronic HBV carriers (i.e. surface antigen

positive) should be monitored for signs and symptoms of active HBV

infection throughout the course of therapy and for several months

following discontinuation of therapy.

Reactivation of HBV is not unique to anti-TNF alpha agents and has

been reported with other immunosuppressive drugs, the letter states.

Very rare cases (less than 1 adverse event per 10,000 treated

patients) of HBV reactivation associated with anti-TNF alpha therapy

have been reported cumulatively, with one (1) report originating from

Canada, according to the letter. Clinically active HBV infection

occurred following a latency period ranging from 3 weeks to 20 months

after initiation of therapy. In the majority of cases, patients were

also being treated with other immunosuppressive drugs, including

methotrexate, azathioprine, and/or corticosteroids. Hence,

establishing a direct causal relationship to anti-TNF alpha agents is

confounded by the presence of these other medications.

Where outcome information was provided, most patients were reported

to have improved after antiviral treatment and/or discontinuation of

the anti-TNF alpha agent. However, fatal outcomes have also occurred

in reported cases, the letter states.

The Canadian Product Monographs for Enbrel, Humira, and Remicade are

being revised to include the above updated safety information.

Managing marketed health product-related adverse reactions depends on

health care professionals and consumers reporting them. Reporting

rates determined on the basis of spontaneously reported post-

marketing adverse reactions are generally presumed to underestimate

the risks associated with health product treatments. Any case of HBV

reactivation or other serious or unexpected adverse reactions in

patients receiving Enbrel, Humira, or Remicade should be reported to

Amgen Canada, Inc., Abbott Laboratories, Ltd., or Schering Canada,

Inc., respectively, or Health Canada

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