At least 35 drugs developed and marketed by biotech companies are anticipated to have more than $500 million in sales in 2011. Of those, 20 are expected to bring in more than $1 billion in annual sales. However, 10 of the top drugs could post lower year-on-year numbers, in some cases because of exchange rates. In 2010, 29 drugs were projected to fall in the $500 million-plus group, and five were projected to show declines over 2009 sales. Product sales as reported by companies listed. (A) Global in-market sales; (B) 2011 sales projected from 1H11 figures; (C) Sales of Synagis are seasonal, extrapolation assumes 4Q11 sales at least match 4Q10 sales