Genentech says FDA approves Actemra arthritis drug

(AP) — Biotechnology company Genentech Inc. says the U.S. Food and Drug Administration has approved its new drug to treat rheumatoid arthritis.

The approval of the drug, Actemra, "marks a major step forward" in the treatment of the disease, Hal Barron, chief medical officer for Genentech and its parent company, the Roche Group, said in a statement. Development of the drug involved five Phase 3 clinical studies and more than 4,000 participants in 41 countries, Genentech said.

Actemra works by blocking the effect of a certain protein associated with inflammation. But because Actemra acts to suppress the immune system, it can also have serious side effects, including severe infections, liver abnormalities and damage to digestive organs.

Rheumatoid arthritis affects about 1.3 million people in the U.S., according to the Arthritis Foundation.

The drug was co-developed with Japan's Chugai Pharmaceutical Co. and has been approved for use in Japan since 2005. It is also approved in the European Union, India, Brazil, Switzerland and Australia.