AstraZeneca has agreed to buy San Diego-based biotech Ardea Biosciences in a $1.26 billion deal announced April 23.

London-based drugmaker AstraZeneca said it would offer Ardea’s shareholders $32 per share. This represents a premium on the value of Ardea’s stock of 54 percent based on the April 20 closing price of $20.84.

“We are delighted to be joining AstraZeneca,” said Ardea President and CEO Barry D. Quart in a statement. “From our earliest interactions, we were impressed with the quality of AstraZeneca’s people and we are confident their commercial strength and global reach will help realize the full potential of our programmes. The Ardea team and I are committed to helping complete development and working to secure registration for lesinurad.”

Lesinurad is Ardea’s most advanced product candidate. It is in Phase III development as a potential treatment for the management of hyperuricemia in gout patients. The condition, which results in an abnormally high level of uric acid in the blood, causes joint inflammation.

Steve Davis, executive vice president and chief operating officer for the 110-employee Ardea, said the process of completing the Phase III development program involving regulatory submission and approval is expected to take two to three years.

“To maximize the potential of the drug certainly we wanted to have a large pharmaceutical partnership, and we’ve done that now through this transaction,” Davis said.

Through this acquisition, AstraZeneca would also add to its pipeline a second-generation gout product that is at the end of Phase I testing. Davis said it is similar to the lead compound, but quite a bit more potent, which would require lower doses but derive similar benefits from the drug.

The boards of directors of AstraZeneca and Ardea have unanimously approved the terms of the agreement, and Ardea’s board has recommended that its shareholders approve the transaction. Ardea shareholders representing approximately 30 percent of the current total shares have agreed to vote in favor of the transaction, according to a company statement.

The deal is expected to close in the second or third quarter of this year.