Rheumatoid arthritis drug being called a game changer: Pfizer’s tasocitinib

One of Pfizer’s late-stage drugs for rheumatoid arthritis (RA), called tasocitinib, has cleared a pair of key hurdles, hitting two primary endpoints for rheumatoid arthritis while failing to overcome a third endpoint.

On the study’s first primary goal, 65.7% of patients who took 10 milligrams of tasocitinib twice a day achieved ACR20, meaning at least a 20% improvement in disease activity and symptoms, after three months of treatment. Nearly 60% of 5 mg patients reached ACR20, compared with 26.7% of those who received a placebo, researchers said.

Pfizer will present the full results of their studies this week at the American College of Rheumatology annual meeting in Atlanta, Nov. 10. Prior to seeking a green signal from the FDA, Pfizer has plans to conduct four more researches on the drug.

Revenue from tasocitinib may help offset Pfizer losses when its top-selling Lipitor cholesterol pill, with $11.4 billion in annual sales, faces competition next year from cheaper copies in the U.S.

Rheumatoid arthritis is an autoimmune disease that causes chronic inflammation of the joints. Unlike the wear-and-tear damage of osteoarthritis, rheumatoid arthritis affects the lining of your joints, causing a painful swelling that can eventually result in bone erosion and joint deformity.

The exact cause of what causes rheumatoid arthritis is not known. Genes, environment and hormones might contribute. Treatments include medicine, lifestyle changes and surgery. These can slow or stop joint damage and reduce pain and swelling.