Abatacept(Orencia): A new drug for rheumatoid arthritis treatment

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Abatacept: A new drug for rheumatoid arthritis treatment

http://www.mayoclinic.com/health/abatacept/AR00053

Abatacept (Orencia) belongs to a new class of drugs called costimulation

modulators. Find out how Abatacept can help people with moderate to severe

rheumatoid arthritis.

A new class of drugs called costimulation modulators may offer hope for

people with rheumatoid arthritis who haven't found relief from other drugs.

The Food and Drug Administration approved abatacept (Orencia) in late 2005

for people with moderate to severe rheumatoid arthritis. Weigh the benefits

and risks of abatacept if you're considering this treatment.

How do abatacept and other costimulation modulators work?

Abatacept and other costimulation modulators work by interfering with your T

cells - a type of white blood cell. T cells play an important role in your

immune system by attacking viruses, bacteria and other disease-causing

agents. Doctors believe your T cells also play a central role in rheumatoid

arthritis, though it isn't clear exactly how they're involved in the

disease. What is known is that if you have rheumatoid arthritis, your T

cells set off a chain of events that are believed to cause your signs and

symptoms.

Abatacept and other costimulation modulators render T cells inactive by

interfering with the process that turns T cells on. If they don't turn on,

your T cells can't activate the cells that cause the inflammation and joint

damage of rheumatoid arthritis.

Your T cells have two switches that must be turned on in order to activate

the cells. Costimulation modulators interfere with one of these switches, so

that the chemicals that would normally activate the switches can't make the

connection. Abatacept sticks to one of the T cell switches, blocking the

switch so that it can't be turned on. Since this allows only one switch to

turn on in the T cells, they can't be activated and therefore can't start

the chain reaction that leads to the signs and symptoms of rheumatoid

arthritis.

Who is abatacept for?

Abatacept is the only costimulation modulator currently available to treat

rheumatoid arthritis in the United States. People with moderate to severe

rheumatoid arthritis who haven't adequately benefited from methotrexate or

tumor necrosis factor-alpha (TNF-alpha) inhibitors, including adalimumab

(Humira), etanercept (Enbrel) and infliximab (Remicade), can consider

abatacept.

Studies have found that abatacept can reduce the signs and symptoms of

rheumatoid arthritis. It can also reverse some signs of joint damage.

Your doctor administers abatacept into a vein in your arm (intravenous

therapy). Each infusion takes about a half-hour. You receive abatacept

infusions every two weeks for the first month, then every four weeks. Some

people may continue to take methotrexate while on abatacept.

People with chronic obstructive pulmonary disease (COPD) shouldn't take

abatacept because it can worsen the signs and symptoms of COPD. Also people

currently taking TNF-alpha inhibitors shouldn't take abatacept.

MORE ON THIS TOPIC

a.. TNF-alpha inhibitors: Treatment for inflammatory diseases

What side effects are associated with abatacept?

Serious side effects have occurred in people taking abatacept for rheumatoid

arthritis. Carefully weigh the expected benefit from this drug against the

possible side effects to decide whether abatacept is a good option. If

you're concerned about potential side effects, discuss them with your

doctor. The most common side effects of abatacept include:

a.. Back pain

b.. Cough

c.. Dizziness

d.. Headache

e.. High blood pressure

f.. Nausea

g.. Painful hands and feet

h.. Rash

i.. Upper respiratory tract infection

j.. Urinary tract infection

Less common but more serious side effects include:

a.. Infections. Because abatacept interferes with your T cells - an

important component of your immune system - you may be more likely to

develop infections while taking this drug. Most infections associated with

abatacept are mild, with upper respiratory tract infections being most

common. Other types of infections include sinus infections, urinary tract

infections, the flu and bronchitis. Severe infections, such as pneumonia,

are possible.

b.. Cancer. People taking abatacept may be at an increased risk of certain

cancers, including lung cancer and lymphoma, though it isn't clear why.

People with rheumatoid arthritis are more likely than the general population

to develop lymphoma. It isn't clear how or if abatacept may increase this

risk.

The long-term effects of abatacept aren't clear because it hasn't been

studied for an extended period.

What does the development of abatacept mean for future rheumatoid arthritis

treatment?

Despite continued research, doctors still aren't sure exactly what causes

rheumatoid arthritis. However, that hasn't stopped researchers from

continuing to develop new drugs to treat rheumatoid arthritis. Abatacept has

helped to prove that T cells play an important role in the disease.

Researchers continue to look for new ways to slow or stop T cells from

activating.