Gilead Sciences Inc. reported on Wednesday its first quarter earnings rose 22 percent relying mostly on sales of its drug for AIDS treatment.

The company had revenue of $1.26 billion leaving behind Wall Street predictions of $1.22 billion. In the same period a year ago its revenue was of $1.03 billion.

Gilead had a net income of $496.1 million or 51 cents a share compared to $407.4 million or 43 cents a share in the same period in 2007. The results surpassed analysts' forecasts who expected 47 cents per share.

Earnings totaled $522.1 billion or 54 cents a share, excluding items.

Product sales surged 36 percent from $840.2 million in the first quarter of 2007, to $1.14 billion in the first quarter this year.

Gilead's sales of its HIV treatment in the first quarter rose as much as 37 percent to $964.7 million including an increase of 39 percent of Turvada sales totaling $479.4 million.

Gilead posted its product sales expectations for 2008 by $4.7 to $4.8 billion. Its shares rose 1.4 percent to $51.80 in closing trade in Nasdaq, but in after trading its shares fell 1.83 percent to $50.85 a share.