Rheumatoid arthritis is a chronic inflammatory disease that leads
to pain, stiffness, swelling and limitation in the motion and function
of multiple joints. If left untreated, rheumatoid arthritis can produce
serious destruction of joints that frequently leads to permanent disability.
Though the joints are the principal body part affected by rheumatoid
arthritis, inflammation can develop in other organs as well.
Over twenty million people suffer from rheumatoid arthritis worldwide
creating a global pharmaceutical market estimated at over $6.3 billion
in 2004. The disease currently affects over two million Americans,
almost 1% of the population, and is two to three times more prevalent
in women. Onset can occur at any point in life but is most frequent
in the fourth and fifth decades of life, with most patients developing
the disease between the ages of 35 and 50.
The main symptom of rheumatoid arthritis is the persistent inflammation
of the joints, usually in a symmetric distribution. This inflammation
causes destruction of cartilage, bone erosion and structural changes
in the joint, which might range from minimal joint damage to debilitating
disease. Patients’ symptoms typically wax and wane, often making
early diagnosis and treatment difficult. Some patients also experience
the effects of rheumatoid arthritis in places other than the joints.
Current Rheumatoid Arthritis Treatments Typically,
early stage rheumatoid arthritis is treated with nonsteroidal anti-inflammatory
drugs (NSAIDs), such as the Cox-2 inhibitors Celebrex® and
Bextra®, along with ibuprofen, Naprosyn ®, and Relafen®.
NSAIDs have a limited effect that is only sufficient for a short period
of time, because they simply relieve symptoms without slowing disease
progression.
Diseases modifying anti-rheumatic drugs, or DMARDs, are the only drugs
that have been shown to alter the course of disease. Doctors prescribe
DMARDs soon after diagnosis and for as long as the patient can tolerate
the drugs. DMARDs include antifolates, gold compounds, sulfasalazine,
hydroxychloroquine and Tumor Necrosis Factor, or TNF inhibitors, anakinra
and leflunomide and biologic treatments that alter the course of disease
through a variety of mechanisms.
Methotrexate
MTX, a classic antifolate, is the most commonly prescribed DMARD and
is typically the first DMARD prescribed therapy for rheumatoid arthritis.
However, the administration of MTX is known to cause serious side effects
such as pulmonary fibrosis and elevations in liver enzymes, which can
be indicative of early liver and kidney damage.
Leflunomide Leflunomide (Arava®), first marketed in 1998 as new oral
DMARD for the treatment of rheumatoid arthritis, is a cytotoxic that
is believed to work by inhibiting the enzyme dihydroorotate dehydrogenase
(DHODH) to prevent DNA synthesis and limit abnormal cell proliferation.
Side effects include diarrhea, abdominal pain or nausea and altered
liver function.
Biologics
Biologics are usually added to a patient’s treatment regimen
once MTX and other DMARDs are no longer an adequate therapy or side
effects have become unmanageable. The most commonly prescribed biologics,
such as Johnson & Johnson’s Remicade®, Amgen’s
Enbrel® and Abbott’s Humira®, block TNF-a, which is a
pro-inflammatory agent found in large quantities in the rheumatoid
joint. (top)
Psoriasis
Psoriasis is a non-contagious, chronic immune-mediated skin disease
affecting between 5.8 and 7.5 million Americans according to the National
Institutes of Health (NIH). With approximately $4.3 billion spent on
psoriasis therapeutics in 2001, the U.S. market is expected to reach
$6 billion by the year 2007.
Psoriasis is a very diverse skin disease that appears in a variety
of forms. Plaque psoriasis is the most prevalent form of the disease,
which characterized by raised, inflamed, red lesions covered by a silvery
white scale. It is typically found on the elbows, knees, scalp and
lower back. About 80 percent of all those who have psoriasis have this
form.
Current Psoriasis Treatments
There are a broad range of treatments to help control psoriasis including
topical treatments, phototherapy (exposing the skin to wavelengths
of ultraviolet light under medical supervision), and systemic medications.
In a survey conducted by the National Psoriasis Foundation in 2001,
less than 40 percent of respondents indicated they were very satisfied
with any of the four therapies assessed in the study (acitretin [brand
name Soriatane®], cyclosporine, methotrexate or PUVA [psoralen
plus ultraviolet light A]). Nearly 80 percent of persons who were very
dissatisfied with their treatment did not have severe disease.
FDA Approved Systemic treatments include:
Cyclosporine Cyclosporine is a prescription systemic medication used to treat psoriasis. In 1995, Neoral ® was FDA-approved to help prevent organ rejection in transplant patients. In 1997, the FDA approved Neoral® as a treatment for psoriasis.
Soriatane
Soriatane® is a prescription medication called an oral retinoid, which is a synthetic form of vitamin A. Synthetic retinoids were introduced as experimental drugs in the mid-1970s and were approved in the United States in the 1980s. Soriatane® is currently the only oral retinoid approved by the FDA specifically for treating psoriasis.
Methotrexate
Methotrexate is a systemic medication usually sold as a generic. Initially used to treat cancer, methotrexate was discovered to be effective in clearing psoriasis in the 1950s and was eventually approved for this use by the FDA in the 1970s.
Biologics
Biologic medications are developed from living sources, such as cells, rather than combinations of chemicals like traditional drugs. The U.S. Food and Drug Administration has approved Amevive® and Raptiva® for the treatment of psoriasis. Enbrel® is approved for the treatment of both psoriasis and psoriatic arthritis, while Humira® and Remicade® are both approved for the treatment psoriatic arthritis.
Other systemics include:
Accutane®, Hydrea®, mycophenolate mofetil, sulfasalazine, 6-Thioguanine. (top)
Inflammatory Bowel Disease (IBD)
According to the latest estimates, there are over one million IBD
sufferers in the U.S. alone with direct and indirect costs amounting
to $1.3 billion each year. IBD is an umbrella term encompassing a number
of chronic, relapsing inflammatory diseases involving the gastrointestinal
tract: two of which are Ulcerative Colitis and Crohn's Disease. Because
they behave similarly and may at times be difficult to differentiate,
the two disorders are grouped together as IBD.
Crohn's Disease is an inflammatory process that can affect any portion
of the digestive tract, but is most commonly seen in the last part
of the small intestine. Ulcerative Colitis is an inflammatory disease
of the large intestine, commonly called the colon. The disease causes
inflammation and ulceration of the inner lining of the colon and rectum.
All forms of IBD may require immunosuppression to control the symptoms.
This consists of mesalazine, steroids, and later of steroid-sparing
agents (such as azathioprine, methotrexate or 6-mercaptopurine) or
biologicals. Severe cases may require surgery, such as bowel resection,
strictureplasty or a temporary or permanent colostomy or ileostomy.
Both
diseases are chronic and onset occurs most frequently in early adult
life, requiring management over a lifetime. (top)
