AMSTERDAM (Reuters) - Shares in Dutch biotechnology firm Pharming (PHAR.AS: Quote, Profile, Research) fell as much as 4.6 percent on Friday after it reported a higher first-quarter net loss due to increased costs.

Pharming, which produces therapeutic proteins in milk of genetically-modified animals, had a first quarter net loss of 6.4 million euros ($10.2 million) compared to a 5.1 million euros loss in the same period last year.

Its cash position at the end of the quarter was 49.2 million euros.

Pharming shares were down 2.3 percent at 0.86 euros in early trade after earlier falling as low as 0.84 euros, underperforming a 0.4 percent higher small-cap index .

The company said it was determined to bring its key drug Rhucin to the market despite not getting approval from European authorities for the drug. It intends to re-submit the request with additional data.

It has said the drug could achieve annual sales of up to 600 million euros in the United States and Europe combined.

"Pharming is fortunate to have a strong financial position which will allow us to take the necessary next steps in our Rhucin program as well as invest in other portfolio programs," the company said in a statement.

"We do not expect a registration for Rhucin in 2008 due to the need for more clinical results, which are expected in the second quarter, and the long regulatory trajectory," Rabo Securities analyst Fabian Smeets said in a note.

Rhucin treats hereditary angioedema (HAE), a disorder characterised by acute attacks of painful swelling of the skin, intestine, mouth and throat and is derived from the milk of transgenic rabbits.