Gilead Sciences Inc.'s (GILD) second-quarter profit climbed 31% as the biopharmaceutical company reported higher sales from its HIV products and added revenue from its acquisition of heart-drug maker CV Therapeutics Inc.

The company, which dominates the HIV treatment market, continued to post solid growth for those treatments, despite a difficult economy.

Gilead reported earnings of $571.4 million, or 61 cents a share, up from $434.8 million, or 45 cents a share, a year earlier.

Excluding stock-based compensation and other items, earnings rose to 69 cents a share from 48 cents.

Revenue increased 29% to $1.65 billion.

Analysts polled by Thomson Reuters expected per-share earnings of 61 cents on revenue of $1.6 billion.

Total costs and expenses grew 32%.

Sales of its key HIV products rose 26% to $1.41 billion. Truvada - which combines two Gilead drugs - recorded improved sales of 18%, as sales of Atripla, its once-daily tablet treatment for HIV, surged 60%, both due to higher sales volume in the U.S. and Europe.

Sales of Viread, which is used to treat HIV and hepatitis B, climbed 5.5%.

Gilead also saw 5.1% growth in its fungal infection treatments and sales surged 79% for its high blood pressure drug.

The company, boosted by its $1.4 billion acquisition of CV Therapeutics, reported sales of $36.1 million for Ranexa, which treats chronic angina. The sales were from the acquisition date of April 15 until the end of the quarter.

In May, Gilead filed a lawsuit against Israeli-based Teva Pharmaceutical Industries Inc. (TEVA) and its U.S. subsidiary for infringement of two patents tied to two of its HIV drugs. Gilead is seeking to prevent Teva from making a generic version of Truvada until 2021, when the U.S. patent expires.

Shares were down 0.8% at $48.15 in after-hours trading. The shares have regained about a third of their value from the 52-week low set in October.

-By John Kell, Dow Jones Newswires; 212-416-2480; john.kell@dowjones.com