Enbrel needs further study on infections issue; new data support early use

The US Food and Drug Administration has asked Immunex to conductpost-marketing studies on its new rheumatoid arthritis drug Enbrel (etanercept) to ascertain whether it can be associated with the development of serious infections. A Dear Doctor letter has also been sent out to warn physicians not to prescribe the drug to patients who have active infections and to exercise caution when giving it to patients with a history of infections or to those with underlying conditions such as advanced or poorly controlled diabetes, which may predispose them to these events.

The move follows the news that 30 of the 250,000 patients treated with Enbrel since it was launched onto the market last year (Marketletter November 9, 1998) developed serious infections, including sepsis, within two to 16 weeks of starting treatment. Six of the patients died as a result. As yet there is no evidence to link the drug to the deaths, although the possibility that Enbrel might exacerbate infections was recognized at the drug's approval, as it inhibits the action of tumor necrosis factor, a component of the body's natural defenses against serious infection.

On approval, Enbrel was contraindicated in patients with sepsis and carried labeling noting that it should be discontinued if a patient developed an infection. This contraindication has now been extended to include all types of infection.