UPDATE 1-Pharming's Rhucin drug takes step toward EMEA nod

* Gets OK for immunology, rheumatology and transplantation

* Agreement is key to get European marketing approval

* Pharming shares up 23 percent

(Adds detail, background, shares)

AMSTERDAM, June 4 (Reuters) - Dutch biotechnology firm Pharming (PHAR.AS) said on Thursday it had taken a step forward in its bid to secure marketing approval from European authorities for its main Rhucin drug.

The Paediatric Committee of the European Medicines Agency (EMEA) has adopted an opinion agreeing with Pharming's paediatric investigation plan for Rhucin in the therapeutic area of immunology-rheumatology-transplantation, Pharming said.

"(The agreement) is a key milestone in Pharming's regulatory plans for the September 2009 submission of the Rhucin marketing authorisation application," Bruno Giannetti, Pharming's Chief Operating Officer, said in a statement.

Pharming shares were up 22 percent at 0.86 euros at 1248 GMT, up from 0.72 euros just before the announcement.

Pharming, which produces therapeutic proteins in milk of genetically modified animals, has no products on the market yet.

Rhucin is Pharming's lead product, for which marketing approval was twice denied by the EMEA.

The drug's main target is treatment of hereditary angioedema, characterised by acute attacks of painful swelling of the skin, intestine, mouth and throat, but Pharming is also looking to use the drug in other areas such as transplantation.

Pharming has spent about 100 million euros ($142 million) in developing Rhucin and is eager to get it into new areas such as organ transplants, where it hopes the drug will reduce cases of rejection. ($1=.7058 Euro) (Reporting by Harro ten Wolde, editing by Will Waterman)