The first new drug to treat lupus in more than half a century won approval from the Food and Drug Administration on Wednesday, offering a new option for people with lupus, an often-debilitating immune system disease.
The drug, Benlysta, is also the first product approved for its developer, Human Genome Sciences, which has accumulated losses of more than $2 billion since its founding in 1992. GlaxoSmithKlinewill help market the drug.
Lupus has been a particularly challenging disease for the pharmaceutical industry. At least seven drugs in the last several years have suffered setbacks in clinical trials. Doctors and patient advocates said that having a drug finally make it to market would encourage other pharmaceutical companies to pursue treatments for the disease.
“It’s important to the field to have an approved product,” said Dr. David S. Pisetsky, a professor of medicine at Duke and a scientific adviser to the Lupus Research Institute, which finances efforts to develop treatments.
Aspirin was approved for the disease in 1948, and two other drugs gained approval in 1955 — corticosteroids and Plaquenil, originally a malaria drug. However, there are several other drugs that doctors use off-label that experts say appear to have some effectiveness.
Benlysta’s approval was expected because an advisory committee to the F.D.A. had endorsed the drug in November by a 13-to-2 vote, despite the reservations of many committee members that the drug was only marginally effective.
In the trial that took place partly in North America, about 43.2 percent of patients receiving Benlysta experienced a reduction in symptoms after one year compared with 33.8 percent of those on a placebo. Over all, the F.D.A. estimated, about 11 patients must be treated with Benlysta for one to benefit.
The drug is not recommended for patients whose disease is severely damaging their kidneys or central nervous systems because it was not tested on those patients.
Moreover, African-Americans, who have a far higher incidence of lupus than white people, did not appear to respond to the drug. In a news release on Wednesday, the F.D.A. said there were too few African-Americans in the trials to draw a definitive conclusion. Therefore, Human Genome Sciences has agreed to do another trial to assess the safety and effectiveness of the drug in people of African descent.
Still, some patients benefited and there were signs, though not consistent, that some patients were able to reduce doses of steroids, which cause weight gain, bone-weakening and other side effects.
Saudia Sinclair of the Bronx, who has been taking Benlysta since participating in an early clinical trial in 2003, said the drug had cleared up her skin lesions, partly relieved her fatigue and allowed her to stop taking steroids. “It was the reason I was able to get through college and grad school, and I’m now working as a social worker,” she said.
In a trial, there were more deaths and serious infections among those who received the drug compared with those on a placebo. However, this finding did not concern experts on the F.D.A. advisory committee. Side effects of Benlysta included nausea and diarrhea.
The companies said the price of Benlysta would be about $35,000 a year.
Many analysts expect worldwide sales to eventually exceed $2 billion a year. But initial sales are expected to be slow because insurers might balk at paying for the drug, at least until patients try less expensive alternatives.
One study estimated that about 300,000 Americans, many of them young women, have systemic lupus erythematosus, the most common form of the disease and the one for which Benlysta was approved.
The disease occurs when the immune system attacks the body’s own cells. Symptoms vary widely but include fatigue, pain, rashes, and damage to the kidneys, heart, lung and brain.
Benlysta, which is given as an intravenous infusion every 28 days, is a monoclonal antibody that curbs the immune system by inhibiting a protein in the body called B lymphocyte stimulator. Human Genome discovered that protein by sifting through its database of human genes. That makes Benlysta, also known as belimumab, one of the first drugs to emerge from the genomics revolution.