Rheumatoid Arthritis Goes on Trial

A clinical trial of a new drug in development for the treatment of rheumatoid arthritis (RA), has shown it to be well tolerated, with side-effects going away affter three months.

Researchers writing in BioMed Central's journal Arthritis Research and Therapy have shown that treatment with Masitinib significantly reduced the severity of active arthritis.

Olivier Hermine worked with researchers from several French hospitals to carry out this trial in 43 patients with arthritis that is resistant to current treatments. Hermine said, "In choosing which interventions to use for the management of rheumatoid arthritis, it is important to recognise that treatment should aim to keep the disease in remission and not be used intermittently to manage exacerbations."

We are encouraged from this study that Masitinib not only appears to be effective, but that within the first 3 months of treatment the worst of its side-effects were over, possibly making it suitable for long-term treatment regimens. He adds, "The results of this study also help establish the critical role of mast cells in the pathogenesis of rheumatoid arthritis and demonstrate their viability as a therapeutic target. There is sufficient compelling evidence to warrant further placebo-controlled investigation."

Masitinib inhibits the activity of mast cells, a component of the immune system thought to be involved in the pathogenesis of rheumatoid arthritis. The clinical improvement described in the study was supported by laboratory evidence of reduced inflammation. The authors found that adverse effects of the treatment were mainly mild to moderate.

Alain Moussy from AB Science, a pharmaceutical company who are developing Masitinib for multiple indications in human and animal medicine said, "This is a milestone article for us, being the first publication of Masitinib in a human study." Speaking about the drug, Moussy said, "Our preclinical studies have shown that Masitinib selectively targets cell receptors known to be involved in various disease processes but does not affect those associated with toxicity, particularly cardiotoxicity."

There are approximately 1.3 million rheumatoid arthritis sufferers in the United States, about 75 percent of whom are women. Rheumatoid arthritis damages the joints, most commonly in the hands, feet, and cervical spine. Inflammation can also affects other organs and systems in the body such as the skin, lungs (fibrosis), kidneys (amyloid protein deposits), and cardiovascular system (increased risk for heart attack and stroke, as well as fibrosis and pericarditis). A clinical diagnosis can be made on the basis of symptoms, physical exam, radiographs, x-rays and lab tests. There are many prescription medications used to treat rheumatoid arthritis such as hydroxychloroquine (Plaquenil®), chloroquine (Aralen®), leflunomide (Arava®), and methotrexate (Rheumatrex ®). Non-pharmacological treatment includes psychical therapy, orthoses, and nutritional therapy but these do not stop progression of joint destruction. Analgesia (painkillers) and anti-inflammatory drugs, including steroids, are used to suppress the symptoms, while disease-modifying antirheumatic drugs (DMARDs) are required to inhibit or halt the underlying immune process and prevent long-term damage. Recently the newer group of biologics, such as abatacept (Orencia®), adalimumab (Humira®), etanercept (Enbrel®), infliximab (Remicade®), and rituximab (Rituxan®) have increased treatment options.