Glaxo's U.S. Avandia decline starts to stabilise

LONDON, June 19 (Reuters) - The U.S. market share for GlaxoSmithKline Plc's (GSK.L) Avandia diabetes drug has started to stabilise after a widely publicised medical report suggesting it increases risk of heart attack, new prescription data shows.

Industry analysts at Citigroup said on Tuesday IMS Health data for the third week since publication of the critical analysis showed Avandia accounted for 7.4 percent of new prescriptions against 7.6 percent a week earlier.

The previous week, Avandia's share was 8.8 percent and the week before that 12.1 percent.

Total prescription share was 9.1 percent in the week to June 8, against 9.3, 10.1 and 12.3 percent in the preceding weeks.

Deutsche Bank said more up to date prescription data compiled by ImpactRx revealed the new written prescription share for Avandia was now well off its lows, with its share in the primary care physician setting having fallen from 12.9 to 3.1 percent but rebounding to 5.9 percent for the week ending June 17.

Sales and prescriptions for Avandia plunged after the May 21 analysis in the New England Journal of Medicine that suggested the Glaxo pill raises the risk of heart attack by 43 percent.

The analysis by Steven Nissen, head of cardiology at the Cleveland Clinic, was based on conclusions drawn from pooled data from 42 trials involving nearly 28,000 patients.

Glaxo disagreed with the findings and said there was compelling data from other trials showing Avandia was just as safe as other diabetes medicines.

An advisory panel of the U.S. Food and Drug Administration is due to study the issue of Avandia's safety at a meeting on July 30.

((Reporting by Ben Hirschler; editing by Greg Mahlich; e-mail: ben.hirschler@reuters.com; Reuters Messaging: ben.hirschler.reuters.com@reuters.net; tel +44 20 7542 5082)) Keywords: GLAXO AVANDIA/

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