Pfizer rheumatoid arthritis drug passes clinical hurdle

A rheumatoid arthritis medicine discovered and developed by Pfizer Inc. scientists in Groton and New London showed promise in reducing the physical symptoms of the disease, including swelling and sore joints, according to a clinical study released today.

The study of the experimental drug tofacitinib, a so-called JAK inhibitor previously known as tasocitinib, was the second successful late-stage trial of the Pfizer pill, which would be a major breakthrough for rheumatoid arthritis sufferers. A previous study showed the drug reduced pain and inflammation for nearly three-quarters of disease sufferers.

“No new safety signal was detected,” Pfizer noted in a summary of the study findings.

Rheumatoid arthritis, an autoimmune disease that causes inflammation in the joints, affects an estimated 1.3 million people in the United States, the company said. The overall market for disease sufferers worldwide has been estimated at $13 billion, with tofacitinib expected to bring in up to $2 billion annually if it eventually wins regulatory approval, most likely next year.

Pfizer is currently finishing four other clinical trials for tofacitinib. The results are expected by the middle of this year.