Psoriatic Arthritis (PsA) Fact Sheet
Looking for the facts about Psoriatic Arthritis and the Psoriatic Arthritis market? The following information comes from our Psoriatic Arthritis Market Info Report™ which is available for purchase and download on our website, Drug Market Info.
What is Psoriatic Arthritis?
Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis. Patients develop swelling, stiffness and tenderness of joints and surrounding ligaments and tendons. The most commonly affected sites are the heel, Achilles tendon and joints of the fingers and toes. Many patients also have skin and nail disease. Like skin disease only, PsA tends to remit and flare over time. It was initially believed that PsA is milder than Rheumatoid Arthritis, but newer evidence suggests it may be as destructive as RA.
There are 5 types of psoriatic arthritis with the most common being asymmetric oligoarticular arthritis (50%+), although considerable overlap exists between types. PsA severity is determined by the number of joints affected, the pain level, how quickly the disease progresses, quality of life impact and X-ray findings. PsA can be mild or it can be severe, debilitating and life-altering. Interestingly, arthritis severity is not always correlated with skin disease severity. Up to one-half of patients show progression on X-ray just 2 years after diagnosis, but the speed of progression is variable and unpredictable.
Patients with psoriatic arthritis have the same co-morbidities as psoriasis patients, such as Crohn’s disease, ulcerative colitis, multiple sclerosis, cardiovascular problems, metabolic syndrome and even psychiatric problems (depression, anxiety, suicide). It is estimated that 80% of patients with PsA also have psoriasis skin disease. There is also a genetic component to PsA – a patient with a first-degree relative with PsA has a 50 fold increased risk of developing PsA.
How is Psoriatic Arthritis Diagnosed?
There isn’t a blood test or culture for diagnosing PsA and it’s easy to miss. PsA starts with prolonged early morning or immobility-induced stiffness and tender swollen joints. Many patients believe they are suffering from a sporting injury and tend to delay mentioning it to their doctors. A diagnosis of PsA is made by a rheumatologist using a tool called CASPAR that evaluates signs and symptoms, X-ray images and patient and family history of psoriasis. Other forms of arthritis are also ruled out (especially Rheumatoid Arthritis).
Patients are usually diagnosed with psoriatic arthritis 8-10 years after skin disease appears. Unlike psoriasis, which often develops before age 25, PsA is generally diagnosed in patients age 30-50, although the disease can and does occur at any age, even in children.
How Many People Have Psoriatic Arthritis?
Estimates of the number of patients in the U.S. with psoriatic arthritis range from 311,000 to 777,000. PsA is difficult to measure and the numbers are controversial because they vary from 6% to 42% of all psoriasis patients. The National Psoriasis Foundation estimates that a third of all psoriasis patients go on to develop psoriatic arthritis.
Psoriatic arthritis affects men and women equally, but has about double the prevalence among whites versus blacks or Native Americans.
How is Psoriatic Arthritis Treated?
It is currently believed that treatment modifies PsA progression and has a positive effect on the course of skin disease and other co-morbid conditions. PsA treatment is comprised of three modalities: pain relievers, DMARDs and biologics. For patients with milder disease, non-steroidal pain relievers such as Advil® or COX-2 inhibitors (Celebrex®) are effective for controlling pain and inflammation. Local corticosteroid injections can be used for a joint that is resistant, and in select cases, systemic corticosteroids are sometimes useful. The downside of all these therapies is that they can cause skin flares and do not prevent disease progression.
For PsA that is progressing or is moderate/severe, more powerful medications are often required and may need to be used in various combinations to control disease symptoms and prevent joint erosion. DMARD, which stands for disease modifying anti-rheumatic drugs or biologics are used. DMARDs are older drugs, like methotrexate, that treat both skin and joint disease and inhibit further joint deterioration. Interestingly, these drugs are approved for use in rheumatoid arthritis, but are used off-label for PsA.
Biologics are the first drugs to be specifically evaluated and tested for use in PsA and are now standard therapy. There are 4 different biologics approved for treating psoriatic arthritis. Enbrel® and Humira® are the biologics used most frequently, but a newer drug is also showing promise (Simponi®). Biologics are often used in combination with methotrexate for increased efficacy and are interchanged with each other when efficacy wanes. Only the Biologics are capable of treating all the symptoms of PsA.
How Much Does Psoriatic Arthritis Treatment Cost?
The patient price for a DMARD ranges from $500-$5,000 per year (all DMARDs used for PsA are generic drugs) and the biologics (no generics available) run about $30,000 per year. Because of this price difference, patients are often started on a DMARD, with a biologic added or substituted based on response.
What’s On The Horizon For New Psoriatic Arthritis Treatments?
There are 5 drugs in Phase 3 clinical development and a few in Phase 2. Virtually all the drugs in development are for biologic therapies that focus on inhibition of several inflammatory-related targets. There are 10 times the number of studies ongoing for Rheumatoid Arthritis – drugs used here are often used off-label for PsA.
What Is The Patients’ Perspective On Psoriatic Arthritis?
Psoriatic arthritis is a potentially crippling and painful disease with severe physical and life-altering ramifications – patients need treatment to function. Surprisingly, the most disabling symptom of PsA isn’t joint pain or stiffness; it is a deep and profound fatigue which only the biologics alleviate.
Psoriatic arthritis patients are well aware that treatment is associated with side effects and long-term risks, but they are willing to accept more risk. It can mean the difference between a wheel chair and full function. Many patients do experience waning efficacy and must “switch” therapies after several years. Still others find that while joint disease is well-controlled, skin disease is not and requires management with other therapies. “Drug holidays” are one way patients try to limit their long-term exposure to the safety issues and maybe ensure the drug keeps working. Waning responses are common no matter what therapy is used.
To provide a voice for millions of psoriatic arthritis sufferers, the National Psoriasis Foundation (NPF) was established. The NPF is a patient-driven nonprofit advocacy and support group. It also raises money to fund research and maintains the Victor Henschel BioBank, the largest source of DNA samples and clinical registry for psoriasis and psoriatic arthritis in the world.
Posted on August 19, 2011, in Patients' Perspective, Psoriatic Arthritis and tagged Celebrex, DMARD, Enbrel, Humira, joint pain, methotrexate, psoriasis, psoriatic arthritis, Psoriatic Arthritis Market Info, Rheumatoid Arthritis, Simponi, The National Psoriasis Foundation. Bookmark the permalink. 4 Comments.