Federal health officials said Friday that the first new drug developed to treat lupus in decades relieves disease symptoms, but they questioned the significance of its benefits, which varied across different patient groups.
Human Genome Sciences is asking the Food and Drug Administration to approve Benlysta to relieve symptoms of lupus, a difficult-to-treat ailment in which the body attacks its own tissue and organs. If approved, the drug — which is being codeveloped with GlaxoSmithKline — would be the first new lupus treatment in about 50 years.
Two of three studies submitted by the companies show Benlysta improved patients' scores on a test that measures lupus symptoms.
However, FDA reviewers raised a number of questions about the strength of Benlysta's effect in briefing documents posted online Friday.
"The robustness and the clinical meaning of the efficacy findings warrant discussion," states the FDA review.
Regulators pointed out that African American patients actually appeared to fare worse when taking the drug. Reviewers were also concerned that the drug's benefit appeared greater among patients studied in Latin America, compared with those from the U.S. and Canada.
The FDA will ask a panel of outside experts about these discrepancies and also to vote on Benlysta's safety and effectiveness at a meeting next Tuesday. The FDA is not required to follow the group's advice, though it often does.
Panelists will also likely discuss the longevity of Benlysta's effect.
In the companies' studies, patients taking Benlysta — known generically as belimumab — had significantly fewer lupus symptoms after one year compared with those taking a placebo injection. However, follow-up studies have shown that after 76 weeks, patients taking Benlysta do not fare significantly better than those taking a sham treatment.
The FDA also outlined potential side effects of Benlysta, including infections, depression and suicide.
"If belimumab only has a modest effect for some patients and manifestations, is a possible increased risk of death, infection, or neuropsychiatric adverse effects worth the potential benefit?" ask the FDA reviewers.
Despite the somewhat critical review from the FDA, most analysts believe Benlysta will win approval from the FDA, simply because there are so few options for Lupus patients.
Lupus occurs more frequently in women than men, though it's unclear why. The disease is marked by skin rashes, joint pain and swelling, inflammation of the kidneys and the fibrous tissue surrounding the heart, as well as other problems.
Current treatments for lupus include steroids, which can cause bone fractures, and chemotherapy drugs, which cause hair loss, anemia and diarrhea.
"Existing medications have been helpful in prolonging life, but at what cost? Is quality of life the cost of prolonging life?" asked Sandra Raymond, President of the Lupus Foundation of America, one of several patient groups expected to testify next Tuesday.
The FDA is scheduled to make its final decision on Benlysta by Dec. 9.
According to Human Genome Sciences, Benlysta blocks the antibodies that cause lupus symptoms in a subset of roughly three-fourths of patients. The company estimates there are 1.5 million patients in the U.S. who could benefit from the drug and 5 million worldwide.
Human Genome Sciences Inc., of Rockville, Md., and GlaxoSmithKline PLC, of Britain, are also seeking approval to market the injectable drug in Europe.
Shares of Human Genome Sciences fell $2.40, or 9.1 percent, to $24.08 in afternoon trading.