Biotech Stock Roundup: Amylin Ascends

The Nasdaq Biotechnology Index was up 1.3% but slightly lagging the broader market Thursday, with the Nasdaq up 1.7% and the Dow up 1.3%.

Among those gaining in afternoon trading:

Amylin(AMLN Quote) shares were rising 5% to $12.99 on news that billionaire investor Carl Icahn was building his position in the company as he tries to replace some board members.

Dendreon (DNDN Quote), which announced it would give a company update via Webcast at the upcoming BIO CEO conferences, was lately up 4.8% to $3.68.

Medivation (MDVN Quote) was up 1.7% to $19.56.

Elan(ELN Quote) was down 0.5% to $8.01.

Genzyme(GENZ Quote) was up 1.2% to $72.01.

Biogen Idec(BIIB Quote) was up 0.6% to $53.04.

Among those losing:

Genentech (DNA Quote) shares were down 0.7% to $81.90.

Amgen(AMGN Quote) was down 0.1% to $56.71.

Gilead Sciences(GILD Quote) was down 0.4% to $51.78.