UPDATE 1-GSK seeks EU marketing approval for lupus drug

* Says to seek U.S. FDA approval by end June

* Submission includes results from 2 late-stage trials

June 7 (Reuters) - GlaxoSmithKline Plc (GSK.L) has sought European regulators' marketing approval for its experimental lupus drug Benlysta, being developed along with Human Genome Sciences Inc HGSI.O, the companies said.

The submission to the European Medicines Agency (EMA) includes results from two late-stage trials, Human Genome said.

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

GSK said it plans to submit a Biologics License Application for the drug to the U.S. Food and Drug Administration later this month.

Benlysta is being developed by GSK and Human Genome under a co-development and marketing agreement signed in 2006. (Reporting by Shailesh Kuber in Bangalore; Editing by Gopakumar Warrier)