UPDATE 4-Gilead 1st-quarter profit rises 22 pct

(Adds analyst comment, background, updates share price)

By Deena Beasley

LOS ANGELES, April 16 (Reuters) - Gilead Sciences Inc (GILD.O) said on Wednesday its first-quarter profit rose a better-than-expected 22 percent as its AIDS drugs continued to take market share.

But the company did not change its outlook for full-year sales, saying some U.S. states stockpiled the drugs in the first quarter. Shares fell slightly in after-hours trading.

Foster City, California-based Gilead said quarterly net profit increased to $496.1 million, or 51 cents per share, from $407.4 million, or 43 cents per share, a year ago.

Analysts, on average, expected 47 cents per share, according to Reuters Estimates.

"It's a very strong quarter. They beat on the top line, and they beat on the EPS line ... very strong all around," said Rodman & Renshaw analyst Mike King.

First-quarter revenue jumped 22 percent to $1.26 billion, beating the $1.22 billion expected by Wall Street analysts. Product sales increased 36 percent to $1.14 billion during the quarter.

Gilead has benefited from the emergence of AIDS trial data earlier this year showing that regimens containing Epzicom, a two-drug combination pill sold by GlaxoSmithKline Plc (GSK.L), were less effective at controlling the HIV virus for some patients than regimens containing Truvada, which combines Gilead's Viread and Emtriva. Glaxo's drug was also associated with a higher risk of heart attack.

Gilead's first-quarter sales of HIV drugs rose 37 percent to $964.7 million, which included a 39 percent jump in sales of Truvada to $479.4 million.

Sales of the newer Atripla, which combines Truvada with Bristol-Myers Squibb Co's (BMY.N) Sustiva into a single pill, rose 70 percent to $324.2 million.

King said Atripla sales beat the average Wall Street estimate of $311 million, while sales of Truvada "blew away" the average estimate of $457 million.

John Milligan, the chief financial officer and chief operating officer, said on a conference call the company still expects full-year 2008 product sales of $4.7 billion to $4.8 billion, mainly because some U.S. states bought larger-than-normal volumes of AIDS drugs in the first quarter. That could result in lower orders in the second quarter.

He also said the exact timing of pricing approvals and drug launches in European countries is still uncertain, and foreign exchange rates remain volatile, making it difficult to predict their impact on revenue.

Sanford Bernstein analyst Geoffrey Porges said, "It doesn't surprise me at all that companies are conservative about managing their guidance through the year. I don't think that's an issue."

He said it was clear that revenue was boosted from stockpiling by a couple of big states.