UPDATE 1-PREVIEW-Odds stacked against Human Genome's lupus drug

* What: Results from first late-stage trial of lupus drug

* When: July 20, Monday

* Analysts skeptical about trial outcome (Adds stock movement, analyst comment)

By Himani Sarkar and Esha Dey

BANGALORE, July 16 (Reuters) - Human Genome Sciences' (HGSI.O) lupus drug Benlysta faces long-odds to reaching the market, given disappointing early trial results as well as a history of multiple prior drug failures in an indication that does not readily lend itself to treatment.

It has been more than three decades since a new therapy has been approved for systemic lupus erythematosus (SLE), which occurs when the body's immune system attacks healthy cells and tissues.

"We note that historically, drug development in SLE has been extremely difficult... and view the Benlystaprogram similarly; with cautious skepticism, following recent SLE failures," UBS analyst Maged Shenouda said in a note.

It is tough to assess a treatment's effectiveness as SLE tends to flare up and wane.

Analysts also cited disappointing data from the drug's mid-stage trial in 2006 as a cause for concern.

However, Human Genome shares rose as much as 45 percent in high-volume trade on Thursday, which Barclays Capital's Jim Birchenough attributed to market speculation ahead of key results.

The stock later pared some of these gains to close up 22 percent at $3.35.

Results from Benlysta's first late-stage study will be released on July 20.

The study, codenamed BLISS-52, was designed to measure patient response rate to the drug at the 52nd week.

"Fundamentally, odds are against a robustdata set," Jason Kolbert at ThinkEquity LLC said in a note.

"We cannot predict with accuracy the outcome of the (late-stage) clinical trial," he wrote.

The graveyard of compounds that failed clinical studies in the SLE indication includes Biogen Idec Inc (BIIB.O) and Genentech Inc's Rituxan, and La Jolla Pharmaceutical Co's (LJPC.O) Riquent -- both of which failed in late-stage trials.