Europe's regulator digs in for drug data fight LONDON (Reuters) - The head of Europe's medicines regulator is digging in for a fight over data transparency after being stopped from releasing information on drugs from two U.S. companies by a court ruling. Defeat for the European Medicines Agency (EMA) at the hands of AbbVie and InterMune highlights a growing battle between campaigners for more openness and companies which fear it will harm their business. The influential Pharmaceutical Research and Manufacturers of America lobby group said in a statement after Tuesday's ruling that industry supported responsible data sharing but "the EMA's current and proposed policies fail to respect these principles." EMA Executive Director Guido Rasi believes the pharmaceutical industry will be the loser in the long run if it does not accept the need for greater transparency in the face of mounting public distrust. "If the court decides we have to stop the release of data, I think that would be the worst possible boomerang for the industry," he said in an interview. The most powerful weapon we have to tackle distrust is transparency. The EMA said it intended to appeal the interim ruling by the European Union's general court preventing it from releasing documents until a final decision is given. The London-based watchdog has been on a collision course with some drugmakers since deciding to lift the lid on previously secret clinical trial data that is submitted by companies as part of the application process for new medicines. Since November 2010, the EMA has released nearly 2 million pages of detailed clinical trial information - an approach it says reflects growing public demands for more openness to ensure that drugmakers cannot conceal adverse drug effects. Its policy was challenged, however, by both AbbVie and InterMune, which sought an injunction in cases relating to requests for the release of data about their drugs. In the case of AbbVie, information had been sought about its rheumatoid arthritis drug Humira, the world's top-selling medicine. One of those seeking the data was UCB, a rival Belgian drug company. The InterMune case also related to information sought by a potential competitor. An AbbVie spokeswoman said the U.S. company supported transparency of clinical research for the benefit of patients, but was concerned that commercially confidential information contained in EMA filings could help competitors. Ben Goldacre, co-founder of the AllTrials campaign for data disclosure and author of "Bad Pharma," a book criticizing the industry, said the interim ruling was a "disgrace." "Forcing them (the EMA) to hide this information is nothing short of absurd," he said. The EMA plans to step up transparency further by establishing a process for the release of full clinical trial data, which will come into force on January 1, 2014. The agency is currently consulting on how exactly to publish the data proactively - an initiative that Rasi said would take account of the views of all concerned parties, including pharmaceutical companies. Some industry executives fear full transparency will undermine incentives for future investment by releasing data that has been generated in trials paid for by companies and effectively helping rivals. But Rasi said such issues could be addressed by appropriate "rules of engagement," including measures to prevent those groups who receive data from unfairly exploiting the information to undermine commercial data exclusivity rights. Similar rules would also ensure that patient confidentiality was not compromised, he added. Public distrust of drug companies and the regulatory authorities that police them has grown in recent years, following a series of scandals over the safety of drugs such as Merck & Co's now withdrawn painkiller Vioxx and GlaxoSmithKline's (GSK) diabetes pill Avandia. The decision by the EMA to opt for greater openness comes at a time of rising demands for transparency, with the British Medical Journal and others raising concerns that too many drugs are approved on the basis of selective evidence. The EMA's stance has triggered varied responses from drugmakers. While AbbVie and InterMune opted for court proceedings, GSK said last year it would routinely release patient-level data from its trials. Roche this month agreed to hand over data from all clinical trials of its best-selling flu drug Tamiflu to a group of outside researchers after a four-year fight. Editing by Keith Weir and David Brunnstrom