UPDATE 3-Human Genome, GSK lupus drug fails secondary goals

* Say Benlysta did not meet secondary goals

* Human Genome shares down as much as 12 percent (Recasts; adds details, analysts' comments, updates stock movement)

April 20 (Reuters) - Human Genome Sciences Inc (HGSI.O) and partner GlaxoSmithKline Plc (GSK.N) said their experimental lupus drug did not meet its secondary goals of a late-stage trial, sending Human Genome shares down as much as 12 percent.

The late-stage study, named BLISS-76, was evaluating the response rate of the drug Benlysta over a dummy drug, both in combination with standard therapies, and the secondary goal was to show statistically significant improvement at 76 weeks of treatment.

The trial also failed to reach statistical significance in several other secondary goals, the company said in a statement.

Despite the disappointing data from the 76-week study, analysts remain optimistic about the drug and expect a U.S. marketing approval by the end of 2010, as the drug had earlier met the main study goal of improving patient conditions at 52 weeks of treatment.

In November last year, Benlysta, also known as belimumab, met its primary goal in two late-stage clinical trials at week 52. [ID:nN12263099]

Analysts were expecting the stock to go down modestly and said this is a buying opportunity for long-term investors.

"We believe this news removes an overhang, since many investors were cautious that BLISS-76 was underpowered at 76 weeks," Leerink Swann analyst Joseph Schwartz wrote in a note to clients.

Panmure Gordon analyst Savvas Neophytou said there could be some risk if the drug's efficacy wanes with time because lupus is chronic disease and it would be better if efficacy was maintained or even improved over time.

As the drug showed better results in 52 weeks compared to 76 weeks, chances are payors could try to limit insurance after 52 weeks, analyst Michael Yee of RBC Capital Markets said, but added that patients generally remain on their drug when there are no other alternatives and has some perceived patient benefit.

If approved, the drug will be the first treatment for lupus -- a complex disease which causes the immune system to attack the body's own tissue and organs -- in 50 years.

In a joint statement, the companies said they were working together to complete and submit regulatory applications for the drug in the United States and Europe in the second quarter of this year.

Panmure's Neophytou expects Benlysta to generate revenue of about $220 million within the first full year of its launch, that could go up to $714 million by 2013.

Shares of Human Genome were trading down 11 percent at $28.11 in afternoon trade Tuesday on Nasdaq. They touched a low of $27.72 earlier in the session.

Glaxo shares were trading flat at $39.47 on the New York Stock Exchange. (Reporting by Krishnakali Sengupta in Bangalore; Editing by Maju Samuel)