AstraZeneca confirmed late last week that four civil lawsuits had been filed in Japan by the families of victims claimed to have been harmed by the company’s lung cancer drug Iressa (gefitinib).

A report in the Japan Times published last Friday said the lawsuits allege that AstraZeneca advertised Iressa in Japan before it was approved, and that these ads were misleading because they played down the side effects of the drug.

Japan was the first country to approve Iressa for use in non-small cell lung cancer patients in July 2002, when the drug was still being tipped as a potential blockbuster for the UK’s second-largest pharmaceutical group. Mere months later the drug was being linked to a potentially fatal lung condition known as interstitial lung disease [[28/10/02a]], and matters got worse last year when a post-marketing study found that the rate of ILD in Japan was higher than had been recorded elsewhere [[27/08/04b]].

Since its launch in Japan Iressa has been linked to the deaths of over 600 patients, although an April report from a study group at the Japanese Ministry of Health concluded that Iressa should continue to be used, despite the risk of ILD, as a last-line treatment in NSCLC patients.

The problems with the drug in Japan have also been felt elsewhere. While Iressa was approved in the USA in May 2003, the concerns over ILD and clinical trial data suggesting no survival benefit in NSCLC patients [[20/12/04b]] have led AstraZeneca to change the labelling for the drug and restrict its use to patients in clinical trials [[20/06/05a]]. As a result, the company has withdrawn its marketing application for the drug in the European Union [[05/01/05a]].

Iressa brought in $389 million dollars to AstraZeneca’s coffers in 2004, although this figure is likely to shrink rather than grow in light of the safety and efficacy issues besetting the drug. The company is trying to establish a set of biomarkers that will allow it to target use of the drug only to those patients likely to experience a benefit.