Twenty-nine US states yesterday charged Bristol-Myers Squibb with illegal efforts to block generic rivals to its top-selling breast cancer drug Taxol, according to court papers.

The lawsuit, spearheaded by Ohio, was filed in US District Court for the District of Columbia and charges Bristol-Myers with unfairly profiting from its monopoly over the cancer drug and depriving US consumers of less-expensive versions of the treatment, used primarily for ovarian and breast cancers.

"I find it particularly distasteful that Bristol is illegally profiting from a drug which only exists because taxpayers paid for its development in the first place. That's double-dipping at its worst," said Michigan Attorney General Ms Jennifer Granholm, one of the lawyers involved with the suit.

The active ingredient in Taxol was developed by the National Cancer Institute and rights were then granted to Bristol-Myers.

The lawsuit alleges that cancer patients and healthcare providers were forced to pay significantly higher prices for Taxol even after Bristol-Myers's original US patent protection expired.

Bristol-Myers was not immediately able to comment.

The suit is the latest blow for embattled Bristol-Myers, already suffering from stiff generic competition on its other key drugs and a failure so far to bring new cancer drug Erbitux to market after a $2 billion (€2.12 billion) investment in Erbitux's developer, ImClone Systems.

Generic forms of the drug were approved by US regulators in September 2000 after protracted litigation between generic drugmaker IVAX and Bristol-Myers.

Since then, the drug, known chemically as paclitaxel, has experienced a sharp price decline, and Bristol-Myers has seen sales slump. - (Reuters)