Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune inflammatory disease that affects more than 2 million Americans.

It is the subject of intense interest since it is so common and the lessons learned from it may help in the management of other forms of inflammatory arthritis.

Currently, the initial step upon diagnosis of RA is to start the patient on disease- modifying anti-rheumatic drugs (DMARDS) like methotrexate. It is one of the most effective and best tolerated DMARDS. Other DMARDS such as Plaquenil (hydroxychloroquine) and sulfasalazine (Azulfidine), and leflunomide (Arava) are also used.

Over time (less than 3 months), if the patient has failed one of these agents, or a combination of these agents, biologic response modifiers, such as the TNF inhibitors, etanercept (Enbrel), infliximab (Remicade), and adalimumab (Humira) are initiated.

In general, the biologic response modifiers are used in addition to methotrexate or one of the other DMARDS. For those patients that fail a biologic or a biologic plus methotrexate, the next step is to move patients who have failed a TNF inhibitor and/or other agents, to abatacept (Orencia) or rituximab(Rituxan).

Abatacept differs from other disease-modifying treatments in that it has a different mechanism of action. This therapy blocks costimulation which is a major factor in the Abatacept appears to be effective in treating rheumatoid arthritis, the symptoms and signs of the disease, improving function, and reducing x-ray progression.

A recent study involving abatacept showed that if a patient fails a TNF inhibitor, because of lack of efficacy, then switching to abatacept leads to a more than 50% likelihood of having a significant benefit (ATTAIN trial).

It was demonstrated that more than 50% of patients who received abatacept met at least a 20% improvement, based on a validated scoring system. And, on average, more than 20% of patients also achieved a 50% improvement using the same scale. A little more than 10% had also achieved a 70% improvement.

The Health Assessment Questionnaire (HAQ), which measures the ability of a person with RA to perform activities of daily living, was also evaluated. The HAQ disability index in this study showed a mean improvement of about 0.45 units. That's a significant improvement in function in patients with long-standing, severe, disease.

Other measures of functioning also demonstrated significant differences.

The only significant adverse event was a slight increased risk of headache. Most patients did not stop the medication for any reason.

There is always a potential risk of infection associated with any immune suppressive agent.

The use of abatacept and rituximab are considered to be excellent alternatives in patients who have failed anti-TNF therapy.