NEW APPROVALS: Five more countries will allow sales of Pfizer Inc.'s new twice-a-day pill for controlling rheumatoid arthritis, Xeljanz: Russia, Argentina, Kuwait, United Arab Emirates and Switzerland.

THE MARKET: Nearly 24 million people worldwide suffer from rheumatoid arthritis, a painful, often disabling immune disorder.

THE COMPETITION: Xeljanz could win patients away from pricey, injected biologic drugs approved for multiple immune disorders, including Enbrel, Humira and Remicade. They cost roughly $2,500 a month, compared to just over $2,000 for Xeljanz. It's heavily advertised in the U.S., where it was launched in November, but has dangerous potential side effects.