New targeted treatment for arthritis looks promising

Date: Sep-19-2014There is currently no cure for rheumatoid arthritis - an autoimmune disease that causes

inflammation and bone erosion in the joints - although it can be controlled. Now, a new approach

that targets drugs directly to affected joints while avoiding side effects shows promise in a

mouse study.

Rheumatoid arthritis causes inflammation that damages the cartilage and erodes the bone of the joints, leading to pain and deformation.

The study, led by Dr. Ahuva Nissim, of Queen Mary University of London, is published in the

journal Arthritis Research & Therapy.

Rheumatoid arthritis causes long term inflammation in the synovium - the thin layer of

protective tissue that lines the joints and produces fluid that lubricates them. This long-term

inflammation eventually damages the cartilage and erodes the bone of the joints, leading to pain

and deformation.

Treatments that control rheumatoid arthritis currently involve painkillers, non-steroidal anti-inflammatory drugs (NSAIDs), steroids or another group of small molecule drugs called disease

modifying anti-rheumatoid drugs (DMARDs) that suppress inflammation.

Newer biologic drugs that are designed to reduce inflammation by blocking inflammatory signals

are effective, but unfortunately, they can cause serious side effects such as infection because they

suppress the immune system in the rest of the body as well.

For their study, Dr. Nissim and colleagues developed antibodies that seek out and travel to

damaged arthritic cartilage; they then fused a biologic drug to these antibodies and injected them into

the body cavity of mice with induced arthritis in their joints.

The results showed the drug could be delivered specifically to the arthritic joints, with much-reduced side effects compared with a systemic approach that allows the drug to circulate in the whole

body.

Targeting biologic drugs increases potency while minimizing side effects

Dr. Nissim says they believe their approach to treating rheumatoid arthritis shows promise

because:

"Targeting of biologic drugs to the inflamed joint will result in high local concentrations and

low systemic concentrations, increasing efficacy while minimizing side effects."

Also, she says, the new approach is likely to be effective with a lower total dose, which

reduces the cost of treatment.

The biologic drug they used in their study was the anti-inflammatory cytokine IL-10.

Other studies have shown effective ways of delivering drugs to joints, but these used injections

into the joint. The authors wanted to find a different way, that avoids injection into the joint,

because - as they explain in their study paper - due to the number and inaccessibility of many

affected joints, direct injection "is not a feasible option."

Meanwhile, Medical News Today recently learned how research led by the University of

Illinois at Chicago College of Medicine found that deactivating a

cell protein may halt progress of rheumatoid arthritis. The study shows for the first time that

activation of a single protein on the surface of white blood cells flooding into the fluid around

the affected joints is a trigger for the disease.

Written by Catharine Paddock PhD

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.