New Pill Might Relieve Severe Rheumatoid Arthritis
Studies suggest drug works but may have serious side effects
WEDNESDAY, Aug. 8, 2012 (HealthDay News) -- A new oral medication may be available soon for people with rheumatoid arthritis who have not gained relief from other medicines.
As rheumatoid arthritis progresses, people often struggle with everyday tasks and find walking difficult. To help combat those issues, patients with severe forms of the disease often need drugs that must be injected, typically twice a month.
The new drug, tofacitinib, was approved by an advisory panel of the U.S. Food and Drug Administration in May and could be green-lighted by the FDA this month. However, the drug carries the risk of serious side effects, as do injectable treatments. The risks include blood and lymphatic system disorders, infections, and cancer.
"This is an advance, but it's not a cure-all," said Dr. Roy Fleischmann, study author and clinical professor of medicine at the University of Texas Southwestern Medical Center, in Dallas. "We have not cured rheumatoid arthritis."
Rheumatoid arthritis, which differs from age-related osteoarthritis, is a debilitating autoimmune disorder, meaning the body attacks its own tissues. It is characterized by inflammation of the lining, or synovium, of the joints.
The new drug, called a JAK inhibitor, blocks signals that activate inflammatory immune responses involved in the disease.
The FDA is not required to follow its panel's recommendations, but it usually does. Further evidence supporting the benefits of the drug comes in two studies published Aug. 9 in the New England Journal of Medicine.
Fleishmann explained that while people with the disease have benefitted from the discovery of "biologic" drugs such as Humira (adalimumab), Enbrel (etanercept) and Remicade (infliximab), many patients don't find relief from these medications. Biologic products are large proteins that are available only by injection or intravenous administration. The hope, he said, is that JAK inhibitors will help improve the lives of those not getting enough relief from other medications.
Both studies were phase 3 clinical trials, used to test the effectiveness and safety of potential drug therapies in large groups of people.
In Fleischmann's research, about 700 patients who had been taking methotrexate -- a commonly used drug for rheumatoid arthritis -- with inadequate relief were randomly assigned to take either 5 milligrams (mg) or 10 mg of tofacitinib twice daily, 40 mg of Humira every two weeks, or an inactive placebo.
Patients in the placebo group who didn't see notable improvement in their joint pain were switched after three months to get either 5 mg or 10 mg of tofacitinib. Participants were rated on a commonly used index of disability and checked for clinical signs of disease activity. The 12-month study showed that tofacitinib was superior to placebo and similar to Humira in its effectiveness.
The second study involved about 610 patients who had had an inadequate response to methotrexate. Tofacitinib was found to be associated with reductions in symptoms of rheumatoid arthritis and improvement in physical functioning.
Experts not associated with the study think the new drug, if approved by the FDA, would be a positive treatment option.
"It looks like tofacitinib could be used as a first-line agent, before taking a patient to a biologic," said Dr. Ernest Brahn, professor of medicine and rheumatology training program director at University of California, Los Angeles School of Medicine.
However, he noted that the studies involved a relatively small number of patients and no long-term data.
Dr. David Fox, of the rheumatology division at University of Michigan, Ann Arbor, writes in an accompanying journal editorial that a better understanding of the drug's safety picture is needed to determine at what point patients might turn to tofacitinib.
The cost of the drugs, if approved, is unknown. "My guess is that it will be close to the price of the biologics," said Brahn. Fleischmann estimated that the current cost of those drugs to a consumer without insurance is about $25,000 a year.
Tofacitinib would be manufactured by Pfizer Inc., which funded both studies.
Rheumatoid arthritis affects about 1.3 million Americans, according to the Arthritis Foundation.
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about rheumatoid arthritis.