Systemic lupus is the most common form of the autoimmune disease, lupus, which afflicts about five million people worldwide and causes a slew of symptoms including fever, pain and swelling. Now, sufferers of systemic lupus may be closer to a new drug to treat their symptoms, according to the results of a study announced yesterday. If approved for the market, the drug, which was developed by Human Genome Sciences (HGS) and GlaxoSmithKline, would be the first new treatment for lupus in nearly half a century.
HGS and GlaxoSmithKline had already seen encouraging results with their drug, called Benlysta, in the first clinical trial of 860 patients that was completed in July of this year. The companies were waiting for the results of a second trial to file for approval from the U.S. Food and Drug Administration. HGS states on its Web site that it will file for approval in the first half of 2010.
"The lupus community has waited for decades for one positive phase three trial of an investigative drug developed for lupus. Now we have two," said Joan Merrill, a lupus expert at the Oklahoma Medical Research Foundation, in a statement issued by the two companies. Merrill was an investigator in the trial.
In lupus, the body's immune system attacks its own tissues, with dire outcomes. The most frequent symptoms of systemic lupus are an increase in blood pressure in the lungs as well as inflammation of the kidneys, nervous system and brain. Because the disease is chronic, it persists for more than six weeks, and usually for many years, with symptoms fading in and out of intensity.
A number of factors have been associated with the onset of lupus. Environmental triggers, such as ultraviolet radiation and viral or bacterial infections, may play a part in some cases. In particular, peaks in estrogen levels in women, who make up 90 percent of lupus patients, seem to usher in lupus symptoms. In addition, familial cases of lupus, and the incidence of lupus in pairs of identical twins, suggest that genes are involved. No research as yet, however, has identified which genes are involved in the disease.
Human Genome's Benlysta would be among the first drugs to arise from genomic studies, The New York Times reported. The company based the drug on its discovery of a protein that stimulates B-cells and could be responsible for the autoimmune activity in lupus patients. Benlysta is an antibody that binds and inhibits this stimulating protein.
In the second clinical trial, involving 819 participants, 40.6 percent of the patients who took Benlysta for a year experienced relief from their lupus symptoms, compared to 33.8 percent of the placebo group. Patients in both groups continued to take steroids, which is the conventional treatment for lupus. Whereas steroids have traditionally been used to quell lupus symptoms by suppressing the immune system, they can lead to a number of side effects. In this study, improvement was assessed based on reports from doctors and the proportion of patients who could be weaned off of steroids.
"We take great pride in the innovation and scientific rigor that has made it possible to bring Benlysta to this point," H. Thomas Watkins, HGS president and chief executive officer, said in a prepared statement.
Despite the generally positive results with Benlysta, the results of the second clinical trial fall short of the first in at least one respect. Unlike in the first trial, only the higher of the two doses of drug achieved results statistically better than the placebo. HGS and GlaxoSmithKline say that patients who took Benlysta did not experience side effects.