Enbrel Recommended By FDA Panel for Approval to Treat Ankylosing Spondylitis
Enbrel (Etanercept) is the first biologic recommended for approval by the Arthritis Advisory Committee of the U.S. Food and Drug Administration (FDA) for the treatment of ankylosing spondylitis (AS), as stated in a press release from Enbrel manufacturers Amgen and Wyeth Pharmaceuticals. A supplemental biologics license application is under review by the FDA for the use of Enbrel in treating AS. If approved, Enbrel will be the first anti-tumor necrosis factor-alpha (TNF-a) therapy available to treat the disease. In previous clinical trials involving AS patients, Enbrel has shown significant reduction in pain, as well as improvement in spinal mobility and physical function.
Although some doctors prescribe the drug to people with AS, yet it is not FDA-approved for this group. Currently there are few treatments other than non-steroidal anti-inflammatory drugs (NSAIDs) and steroids to treat AS.
"The committee's recommendation for approval of Enbrel underscores the importance of identifying new treatments to help those with ankylosing spondylitis," said Jane Bruckel, RN, executive director of the Spondylitis Association of America (SAA). "We support efforts to develop treatments for this disease, since spondylitis can dramatically affect people's lives."
Physicians and patients are closer to a new option in the treatment of AS, according to Dr. Victoria Kusiak, vice president of global medical affairs and North American medical director of Wyeth Pharmaceuticals. "We look forward to the opportunity to extend the benefits and impact of Enbrel, beyond rheumatoid arthritis, juvenile rheumatoid arthritis, and psoriatic arthritis patients, to patients who have gone for so long with few aggressive options to significantly reduce the painful symptoms of their disease."
New Results of Trial Involving Enbrel in People with AS
Patients in a phase 3 clinical study accessing the efficacy and tolerability of Enbrel in the treatment of active AS experienced significant and rapid reduction in back pain and morning stiffness, and improvement in spinal mobility and physical function. Preliminary results released from this study showed great improvements within the first two months, and these new results demonstrate sustained results for the remainder of the six-month study. Adverse events were similar to those reported in pervious clinical trials of Enbrel.
"I am excited about these encouraging results with Enbrel, especially since it is the first treatment to show improvement in AS patients' range of spinal motion in a phase 3 study," says Dr. John Davis, assistant professor of medicine at the University of California-San Francisco and associate of the Department of Medicine Clinical Trials Center.
The multi-center, double-blind, placebo-controlled study randomized 277 people with active AS to receive either Enbrel (25mg twice weekly) or a placebo over a six-month period. The primary endpoint of the Phase 3 study was the percentage of participants at 12 weeks and 24 weeks achieving a 20% improvement in back pain, inflammation, and physical function.
At week 12, 60% of patients treated with Enbrel achieved the 20% improvement, while 27% of the placebo patients achieved the 20% improvement.
At week 24, 58% of patients treated with Enbrel achieved the 20% improvement, while 23% of the placebo patients achieved a 20% improvement.
The most frequent adverse events in placebo-controlled rheumatoid arthritis trials were:
- Injection site reactions (37%)
- Infections (35%)
- Headache (17%)
- Only the rate of injection site reactions was higher than that of placebo.
"When we measured spinal mobility and back pain, the most debilitating aspects of AS, we found that patients treated with Enbrel experienced significantly greater improvement in mobility than patients receiving placebo and a 50% reduction in spinal pain," explains Dr. Davis. "Enbrel also had a positive impact on many patients' ability to accomplish everyday tasks, such as being able to more easily put on socks or look over their shoulders without turning their bodies.
What a Phase 3 Clinical Trial Means
The FDA groups clinical trials into four phases, each of which addresses a separate research question.
- Phase I: First, researchers test a new drug or device in about 20-100 healthy volunteers to determine whether it is safe and what side effects it may have. Researchers also study how long the drug stays in the body, which helps them decide what doses to test further. Phase I studies primarily address the question of safety.
- Phase II: Next, researchers test the new drug or device in about 100-300 people to determine whether or not it works and to learn more about possible side effects. So Phase II studies address safety and effectiveness.
- Phase III: Researchers compare the new intervention to current standard therapy to learn whether it offers any advantage. In a Phase III study, several hundred to several thousand people receive the new drug or device. The FDA will only approve drugs that complete Phase III testing.
- Phase IV: To monitor long-term side effects, effectiveness, and other potential uses, researchers continue to study new interventions after they are approved and in regular use.
(Courtesy of www.webmd.com)
Amgen's SAFETY NET Program provides replacement product to medically indigent patients (those uninsured or underinsured with limited financial resources). For Enbrel patients, the Encourage Foundation has been established. To learn more about the enrollment process, contact 1-888-4Enbrel (1-888-436-2735) 9am to 9pm ET, Monday through Friday.
For additional information on Enbrel, please refer to www.enbrel.com, www.rxlist.com, and the Spondylitis Association of America's Message Boards to learn others' experiences with the medication.