By Julie Steenhuysen
CHICAGO (Reuters) - Aiden Gallagher started developing symptoms of lupus at age 11 after a spider bite that left her hand swollen for weeks.
Gallagher, now 18, took strong doses of the steroid prednisone to help control the disease, in which the immune system attacks the body's own tissue and organs.
"Prednisone has completely destroyed my bones. I was a very competitive athlete but I had to stop softball because my bones became so weak they kept breaking," said the Poughkeepsie, New York, teenager. "Hopefully, the next 11-year-old girl will have another option."
For millions of patients like Gallagher, Food and Drug Administration approval on Wednesday of new lupus drug Benlysta represents long-sought relief.
Benlysta, made by Human Genome Sciences, is the first drug in more than 50 years to be approved specifically for patients with lupus. The drug is expected to reap billions of dollars in global sales.
Doctors welcomed the approval as a milestone in lupus treatment. Some said it should encourage the world's largest drugmakers, including Roche's Genentech, Pfizer and Eli Lilly, to forge ahead with more than a dozen development programs for the debilitating and deadly autoimmune disease.
"Getting this approval will lead to pharmaceutical companies wanting to continue to push and get other drugs approved," said Dr. Gary Gilkeson of Medical University of South Carolina and chairman of the Lupus Foundation of America's medical scientific advisory council.
"It's a real watershed event."
Gilkeson, who participated in Human Genome Sciences' clinical trial, still has five patients who continue to take Benlysta, known generically as belimumab.
"They are all very happy with how they are doing on the drug. I think there will be a significant use," he said.
An estimated 5 million people worldwide have lupus, which can lead to arthritis, kidney damage, chest pain, fatigue, skin rash and other problems.
To date, physicians have had limited and problematic treatment options, including immunosuppressant drugs such as Roche's CellCept and steroids such as prednisone.
In clinical trials, Benlysta's most common side effects were nausea, diarrhea, and fever. More deaths and serious infections were also reported with the drug than with a placebo in the studies.
Since the disease is different from patient to patient, it has been difficult to study in clinical trials because it is hard to know if a drug is working, or if a patient has gone into remission.
"This is a major change, a new player in the field of lupus," Dr. Anca Askanase of New York University School of Medicine and the NYU Hospital for Joint Diseases said in a telephone interview. "I think it's extraordinary."
Lisa Williams, a 41-year-old woman from Riverdale, Georgia, has battled lupus the past eight years. She hopes a less toxic drug like Benlysta will help others avoid some of the side effects she has faced from high doses of steroids and other powerful drugs.
"At one point, I was taking 40 pills a day," said Williams, now in remission. "I've had a total of 11 surgeries in these eight years," including having both hips and one shoulder replaced.
(Editing by Michele Gershberg and Peter Cooney)