Friday, July 19, 2013

What's New for Rheumatoid Arthritis?

One source of new information about rheumatoid arthritis is the annual American College of Rheumatology meeting. This year's meeting was held in Atlanta, Georgia from November 7-11.

Some of the interesting findings ion rheumatoid arthritis are summarized below...

One study described the combination of etanercept (Enbrel) and methotrexate in rheumatoid arthritis. The study found that disease progression is less frequent in patients with rheumatoid arthritis (RA) who haven't responded to methotrexate alone if it is continued at the same time the biologic drug etanercept (Enbrel) is started. After randomizing "151 patients with active RA to etanercept, 25 mg twice a week plus methotrexate 6mg to 8 mg/week, or to etanercept alone," researchers found the following... Significant differences in joint erosion scores (joint damage scores) were seen after two years of combined etanercept plus methotrexate compared with etanercept alone. These results were reported by Hideto Kameda, MD, of Keio University in Tokyo, and colleagues at the annual meeting of the American College of Rheumatology (ACR).

Another hot topic at the American College of Rheumatology meeting is an investigational compound called JAK. JAK has attracted increasing interest as a drug target in rheumatoid arthritis because it's pivotal to the inflammatory response. It's an enzyme that serves as the traffic director for the release of tumor necrosis factor and other cytokines (protein messengers) that accelerate inflammation in diseases such as rheumatoid arthritis. The weakness of JAK is that it is an enzyme whose effects can be blocked by an oral, small-molecule drug.

There are three forms of JAK simply known as JAK 1, JAK 2, and JAK 3. Pfizer has a JAK inhibitor called tasocitinib. Earlier reports from the ACR meeting about this compound showed that it was extremely effective as well as possessing an acceptable safety profile. Tasocitinib blocks JAK 1 and JAK3.

Tasocitinib is taken twice a day.

Another JAK inhibitor, called INCB028050, is a product from the Incyte company. Incyte has partnered with Eli Lilly to manufacture and market this compound. The drug produced ACR20 responses (at least 20% reductions in symptom scores) in up to 70% of patients after 24 weeks, and ACR70 responses in nearly 30% of patients, reported Maria Greenwald, MD, of Desert Medical in Palm Desert, Calif. INCB28050 selectively blocks JAK1 and JAK2.

INCB28050 is taken once a day.

Side effects of the JAK drugs include elevations in both HDL and LDL cholesterol of up to 25%, depending on the dosage.

Other side effects that have been seen in the clinical trials with these medicines include an increase in respiratory tract infections, viral infections, including shingles, drops in white blood cell count, increases in platelet count, and slight abnormalities in both kidney and liver function.

On a more mundane note, the drug, leflunomide (Arava), may be an acceptable alternative to methotrexate for use in combination with rituximab (Rituxan) in patients with rheumatoid arthritis (RA) who can't take methotrexate.

Katerina Chatzidionysou, MD, of the Karolinska Institute in Stockholm, reported a study showing these findings at the American College of Rheumatology meeting.

A total of 29.1% of patients on leflunomide and rituximab had a good response at the six month mark. A number of research studies have shown that the B-cell targeting antibody drug, Rituxan, is beneficial in RA, and it has usually been given in combination with methotrexate.

But a big question for doctors has been how to deal with patients who have side effects with methotrexate.

Those of us who see a lot of rheumatoid arthritis patients find this information to be "old hat." But patients with the disease should find some helpful nuggets here.

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