The US Supreme Court could be about to rewrite the rules of innovation in America. A drug patent case this week could profoundly affect not only those who take or make American drugs but also the vitality of the innovation economy.

Those, at least, are the claims made by drug and biotechnology companies lobbying hard to influence the outcome of Merck v Integra. The case tests the basic legal compromise that has fostered 20 years of explosive drug creation in the US: that drug companies should be allowed to use other companies' patents for free when their goal is to bring new drugs to market.