FDA staff cautious on AstraZeneca, Bristol diabetes drug

LONDON (Reuters) - U.S. Food and Drug Administration staff said on Tuesday they were wary about the benefits versus the risks of AstraZeneca and Bristol-Myers Squibb's new diabetes drug dapagliflozin. In documents posted on the agency's website ahead of an advisory committee meeting on Thursday, staff said the latest evidence was mixed in terms of the drug's heart benefits and the possible risk of bladder cancer or liver damage. "As a result of these updated analyses the agency could not conclude with any level of confidence that the purported CV (cardiovascular) benefit associated with dapagliflozin use outweighed the observed imbalance in specific malignancies or potential liver toxicity risks," they wrote. Dapagliflozin - a new kind of drug for type 2 diabetes designed to allow more sugar to be excreted with urine - is already approved in Europe, where it is sold under the brand name Forxiga. But U.S. regulators knocked it back in January 2012, due to concerns over cancer and potential liver injury, prompting the latest review. If approved this time around it would be the second so-called SGLT2 inhibitor drug to hit the U.S. market, after the launch of Johnson & Johnson's Invokana, or canagliflozin, in March. Analysts, on average, forecast worldwide sales of $806 million for dapagliflozin in 2019, according to consensus estimates compiled by Thomson Reuters Pharma. (Reporting by Ben Hirschler; Editing by Martinne Geller and Louise Heavens)