LymphoStat-B was meant to target a substance called BLyS, which researchers believed acted as a trigger for lupus. The drug also had the potential to treat rheumatoid arthritis, another autoimmune disease that affects the joints.

The Rockville-based biotech company said it may continue to study the treatment.

Shares of Human Genome Sciences fell $4.10, or 29 percent, to close at $9.87 Wednesday on The Nasdaq Stock Market, where it has traded in a 52-week range of $8.96 to $15.50.

Some Reduction in Symptoms

The company said LymphoStat-B did not significantly reduce the symptoms of lupus among many study patients after 24 weeks as the company had hoped. It also did not reduce flare-ups during the first 52 weeks, one of the study's goals.

However, tests showed there was some reduction in symptoms among 75 percent of the 449 patients in the study who already had signs of lupus in their blood, helped reduce some of the damaging effects, and was safe for humans. Encouraged by those results, the company said it would consider moving to a late-stage study of the drug, known as Phase 3 trials.

"That to us is a clear path forward to Phase 3," H. Thomas Watkins, Human Genome Science's CEO, said in a conference call.

The company said it planned to consult with its partner on the drug, GlaxoSmithKline PLC, and the US Food and Drug Administration before deciding whether to continue studying LymphoStat-B. Rick Koenig, a spokesman for GlaxoSmithKline, said the company would review the trial "to get a really good understanding" of the results, but hadn't yet decided on how to proceed.

Safer Alternatives

The results were a setback for Human Genome Sciences, which has yet to bring a product to market, and for the treatment of lupus, a disease that hasn't had a new treatment in 40 years.

Roughly 1.5 million Americans, many of them women, have the disease that causes the body's immune system to attack organs such as the kidneys, liver, brain and skin. It can cause swollen joints, rashes, fatigue, fevers and other complications.

Treatment often involves drugs meant for other purposes, such as chemotherapy drugs normally used in cancer patients that suppress the immune system to prevent it from turning on the body. Recent lupus research has focused on treating the disease itself, said Duane Peters, a spokesman for the Lupus Foundation of America.

"Doctors and patients want safer alternatives," he said.

Shouldn't Be Scrapped

LymphoStat-B was meant to target a substance called BLyS, which researchers believed acted as a trigger for lupus. The drug also had the potential to treat rheumatoid arthritis, another autoimmune disease that affects the joints.

Dr. Joan Merrill, head of clinical pharmacology at the Oklahoma Medical Research Foundation and medical director of the Lupus Foundation of America, said LymphoStat-B shouldn't be scrapped because of the clinical trial results. The effects of lupus drugs are hard to gauge because of the nature of the disease, which flares up and fades away. The way Human Genome Sciences measured its results likely led to the disappointing results, she said.

"There are holes," she said. "They are not picking up what is going on with these patients."

The 13-year-old Human Genome Sciences has a handful of drugs in development. Those include a treatment for anthrax that the Department of Health and Human Services is reviewing for possible inclusion in a national biodefense stockpile.

But the company still doesn't have a product on the market and has yet to turn a profit. For the first six months of 2005, Human Genome Sciences posted a loss of roughly $56 million.