UPDATE 1-Pharming says Rhucin data addresses concerns

(adds detail, background)

AMSTERDAM, Sept 22 (Reuters) - Dutch biotechnology company Pharming (PHAR.AS) said on Monday progress in developing its key Rhucin drug meant it was now able to address concerns raised by regulatory authorities earlier this year.

In March, the European Medicines Agency (EMEA) denied approval for the drug, which is produced from therapeutic proteins in the milk of genetically modified rabbits, saying it wanted more test results of repeated treatments.

Pharming said it had analysed over 300 administrations of Rhucin, with more than half in repeat treatments which showed no sign of any relevant safety issues.

"We have been able to address the issues raised by the European Authorities in a very promising way thereby generating data that confirm the effectiveness and safety of Rhucin in repeat use," Chief Executive Francis Pinto said in a statement.

Rhucin treats hereditary angioedema, characterised by acute attacks of painful swelling of the skin, intestine, mouth and throat. Pharming has said the drug could generate annual sales of up to 600 million euros ($879 million) in the U.S. and Europe.

The company said on Monday it hoped the data would support its upcoming registration files and planned to submit a license application for Rhucin with the U.S. Food and Drug Administration (FDA) by the end of the year. It expects to follow this shortly after with a market authorisation application to EMEA.

(Reporting by Catherine Hornby; Editing by Jon Loades-Carter)