Updated from 12:56 p.m. EDT

Human Genome Sciences

( HGSI) said Friday that it had priced a secondary public offering of 11 million shares at $75 a share and that it would use the proceeds for research and development.

Company officials said Human Genome Sciences expected to use the $825 million in proceeds from the offering to begin and expand laboratory and human studies to evaluate drugs based on its protein, gene and antibody research. The Rockville, Md.-based company said it also plans to speed up its continuing research and development efforts in a variety of fields and pursue patent coverage for its genes and potential products.

The stock offering, which increases the company's total shares outstanding to about 120 million, was led by

Credit Suisse First Boston

. The underwriters have an option to purchase an additional 1.65 million shares to cover any over-allotments.

The company's shares rose Friday after the offering announcement, closing regular trading up $6.50, or 8%, at $88.13.

Human Genome Sciences' stock has fluctuated wildly over the past year. Shares leapt from $18.44 last October to $116.38 in March, before dropping back into the mid-$20s a month later. The stock price had been climbing steadily since, trading as high as $100 early this week, but slipped back into the low $80s by Friday morning.

Industry analysts attribute some of the stock's movements to sector-wide volatility.

Last week, when the stock was trading just under $100,

AG Edwards

downgraded the stock to "maintain position," saying the had risen to a "reasonable valuation," and deferred adding positions in the company.

Yet, despite the downgrade, AG Edwards, which makes a market in the stock, emphasized it remains "as positive on the firm as ever, seeing that the story has materially improved since June."

In June, shares of Human Genome Sciences were trading at about half the current value. Since then, the company has licensed two genes for gene therapy uses, put its fourth and fifth product candidates into clinical trials, and acquired

Principia Pharmaceutical

, which provides drug delivery technology.

Human Genome Sciences purchased Principia Pharmaceutical in September for an estimated $120 million in stock, a move widely lauded by industry analysts.

US Bancorp Piper Jaffray

, which rates the company a buy, said the acquisition of Principia's albumin fusion technology had "immediate significance," greatly expanding HGS's development opportunities.

Within weeks of the acquisition, Human Genome Sciences announced it had submitted an application to the

Federal Drug Administration

to begin Phase I trials of a new drug to treat hepatitis C that incorporates the protein-fusion technology. That was almost immediately followed by the announcement that HGS would collaborate with

Aventis Behring

to help develop and market the latter's plasma protein product using a similar technology.

Carolyn Pratt, an analyst at

Needham & Company

, which does not perform underwriting for Human Genome Sciences, said the company has the potential to continue generating a number of products using its technology.

"That's the name of the game in the pharmaceutical industry," said Pratt, who maintains a buy rating on the stock. "Often the clinical trials don't turn out the way you expect. The key is to keep putting quality product candidates into clinical trials."

A.G. Edwards said Human Genome Sciences' growing list of product candidates makes it the world leader in bringing genomic-based medicines into development

Human Genome Sciences researches and develops compounds for treating and diagnosing human diseases based on the discovery and understanding of the medical usefulness of genes.

The company's strength lies in its vast research and data concerning gene sequences. The company uses automated, high-speed technology to uncover sequences of chemicals in genes and has generated a large collection of partial human gene sequences, particularly those responsible for producing proteins, according to

Multex Market Guide

. Its genomic database is one of the largest databases of the genes of humans and microbes in the world.