Shares of Emergent BioSolutions Inc. climbed Friday morning, a day after the company said its fourth-quarter profit nearly tripled as sales of its anthrax treatment BioThrax grew.

The Rockville, Md., company earned $4.2 million, or 13 cents per share, compared with $1.5 million, or 5 cents per share, in the final quarter of 2008.

Revenue climbed 51 percent to $53.8 million.

Analysts polled by Thomson Reuters expected, on average, earnings of 5 cents per share on $51.7 million in revenue.

Emergent also said research and development expenses rose 36 percent to $19.2 million while selling general and administrative expenses climbed 35 percent to $18.7 million.

For the full year, Emergent earned $31.1 million, or 99 cents per share, on $234.8 million in revenue. That compares with 2008 income of $20.7 million, or 68 cents per share, and $178.6 million in revenue.

The company said Thursday its 2009 performance was driven mainly by BioThrax sales. That included a $34 million payment the company received from the federal government based on the Food and Drug Administration's approval of the extension of the vaccine's shelf life to four years from three years.

Emergent also reported an 8 percent increase in BioThrax doses sold in 2009. Product sales revenue last year consisted mostly of $216.4 million in BioThrax sales to the government.

Contracts and grants revenue rose 87 percent to $17.6 million in 2009.

The company's shares advanced 88 cents, or 5.9 percent, to $15.81. The stock has ranged from $9.15 to $20.01 over the past year.