News: Avonex linked to liver damage; no recall yet

FDA and Biogen have made an important update to the prescribing information for AVONEX (Interferon beta-1a) without doing a press release or highlighting it prominently on their websites. On the FDA's website, the information is buried in one of those hard-to-find corners. A press release could not be found on Biogen, the Avonex manufacture, website. AVONEX, a multiple sclerosis (MS) drug was introduced to the market in 1996. In another related development, GlaxoSmithKline said that the FDA has ordered a halt to the trial of its own MS drug, that works similar to Tysabri. (Related article: Tysabri recall)

In the revised letter to the doctors, it is indicated that post-marketing experience from Avonex shows severe hepatic injury, including cases of hepatic failure, in patients taking AVONEX. In some cases, these events have occurred in the presence of other drugs that have been associated with hepatic injury. The potential for hepatic injury should be considered, the revised letter advises, when AVONEX is used in combination with other products associated with hepatic injury, or when new agents are added to the regimen of patients already on AVONEX.

Asymptomatic elevation of hepatic transaminases has also been reported, and in some patients has recurred upon rechallenge with AVONEX. In some cases, these events have occurred in the presence of other drugs that have been associated with hepatic injury. The potential risk of AVONEX used in combination with known hepatotoxic drugs or other products (e.g. alcohol) should be considered prior to AVONEX administration, or when adding new agents to the regimen of patients already on AVONEX. Patients should be constantly monitored for signs of hepatic injury.

Biogen has been in deep trouble since Tysabri recall and its executives are being investigated for insider trading just before the news about Tysabri was made public.