* U.S. firms seeking to block release of drug data by EMA
* AbbVie, InterMune say they defending business secrets
* EU's top court refers case back to lower court
By Ben Hirschler
LONDON, Dec 5 (Reuters) - A legal case over access todetails of clinical trials held by Europe's drugs regulator -sparked by two U.S. firms wanting to keep their data secret -has been hit by delay after the EU's top court sent it back tobe re-examined by a lower body.
The decision leaves in limbo a high-profile fight that haspitched the European Medicines Agency (EMA), Europe's equivalentof the U.S. Food and Drug Administration, against AbbVie and InterMune.
Officials said on Thursday that the vice president of theEuropean Court of Justice had annulled earlier interim orderspreventing the release of data and had referred the matter backto the European Union's General Court for further consideration.
With the legal situation still uncertain, sensitive datafrom trials involving AbbVie's rheumatoid arthritis treatmentHumira - the world's top-selling prescription medicine - andanother drug from InterMune will remain under wraps for now.
"Until a new decision is taken by the courts, we will notrelease the documents relating to the AbbVie and InterMuneproducts," EMA spokesman Martin Harvey said.
Still, the London-based watchdog does not intend to letuncertainty in this case prevent it from continuing its policyof responding to outside requests for documents about clinicaltrials on other medicines.
The EMA has already released millions of pages of detailedclinical trial information about different drugs - an approachit says reflects growing public demands for more openness toensure that drugmakers cannot conceal adverse side effects.
The vast majority of all documents released by the EMA -some 76 percent in the past 12 months, according to Harvey -have been handed over to academic groups and researchers.
BUSINESS SECRETS
AbbVie and InterMune argue in a case brought earlier thisyear that they have a right to the protection of their businesssecrets, since this information could be used by competitors.
In the case of the AbbVie drug, those seeking data includerival Belgian drugmaker UCB.
Spokeswoman Fiona Olivier said AbbVie remained confident theGeneral Court would rule in favour of upholding the provisionalinjunction, since the clinical study reports held by the EMAcontained commercially confidential information.
AbbVie backed sharing of data with qualified researcherswhen this did not undermine its ability to innovate, she added.
Europe's medicines body has been on a collision course withparts of the pharmaceuticals industry since deciding to lift thelid on previously secret clinical trial data.
This data is routinely submitted by manufacturers as part ofthe application process for new medicines and, until recently,it had been view as confidential.
But in 2010 the European Ombudsman, which investigatescomplaints about EU institutions, ruled that the EMA shouldprovide access to it - and the EMA plans to proactively releasedetailed data, rather than just waiting for requests, from 2014.
A number of drug companies have recently shifted theirposition towards more transparency in the face of this pressurefrom the agency and some stern critics in academia.
Pfizer, the largest U.S. pharmaceutical company,became the latest to take a step down this path on Wednesday bybroadening access to information from its clinical trials toindependent researchers and to patients.
Britain's GlaxoSmithKline, meanwhile, has alreadyset up an online system to provide researchers with access toanonymous patient-level data about its medicines.
Glaxosmithkline (GSK)