Enbrel and Psoriasis
6/26/2003
Patients in a second phase 3 clinical study accessing the efficacy and tolerability of Enbrel (etanercept) in the treatment of moderate to severe plaque psoriasis experienced significant and rapid improvement in their symptoms. Adverse events were similar to those reported in pervious clinical trials of Enbrel.
Enbrel is an anti-tumor necrosis factor (TNF-a) medication that is Food and Drug Administration (FDA)-approved for use in adult and juvenile rheumatoid arthritis, and psoriatic arthritis. It is not FDA-approved for psoriasis patients without arthritic symptoms. Since Amgen and Wyeth Pharmaceuticals (Enbrel's manufacturer) have studied Enbrel's use in two large studies of psoriasis patients, they will be seeking FDA-approval for Enbrel in the treatment of psoriasis.
Roughly one-seventh of the 7 million people in the U.S. with the chronic inflammation of the skin condition known as psoriasis have moderate to severe plaque psoriasis. The inflammation drives the formation of red, itchy skin plaques that are painful and potentially disfiguring. TNF is found at high levels in psoriatic plaques and plays a critical role in their formation and maintenance.
In this global, double blind, placebo-controlled, multi-center study, 584 patients were randomized to receive either 50mg of Enbrel twice weekly, 25mg of Enbrel twice weekly, or a placebo. Researchers sought to study what proportion of patients achieved a 75% or greater improvement after 12 weeks of treatment.
Findings
49% of patients treated with 50mg of Enbrel twice weekly and 34% of patients treated with 25mg of Enbrel twice weekly achieved a 75% or greater improvement, compared to 3% of the placebo group.
Physicians accessed their patients as having 'clear' or 'almost clear' skin in 57% of patients treated with Enbrel 50mg twice weekly, and 39% treated with Enbrel 25mg twice weekly, compared to 4% of the placebo group.
Patients were also asked to access the effect of Enbrel on their psoriasis and the impact it made on their lives over the course of the study. Those treated with Enbrel 50mg twice weekly reported 71% improvement after 12 weeks, and patients treated with Enbrel 25mg twice weekly reported 66% improvement. Both groups experienced improvement after just two weeks of treatment.
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.
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)
Enbrel Resources
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.