Pfizer Inc. (PFE), the biggest U.S. drugmaker, confirmed it’s interested in acquiring AstraZeneca Plc (AZN) of the U.K. for about 58.8 billion pounds ($98.7 billion).

A Pfizer acquisition of the U.K.’s No. 2 pharmaceutical company would be one of the largest takeovers in the industry’s history. Pfizer proposed buying London-based AstraZeneca on Jan. 5 for 46.61 pounds a share in cash and stock, and AstraZeneca declined to pursue negotiations, New York-based company said in a statement today. That’s about 14 percent above the closing price April 25 for AstraZeneca.

“The combination of Pfizer and AstraZeneca could further enhance the ability to create value for shareholders of both companies and bring an expanded portfolio of important treatments to patients,” Pfizer Chief Executive Officer Ian Read said in the statement. “A potential combination with AstraZeneca aligns with Pfizer’s current structure and fully supports its existing strategy to build world-class businesses.”

An acquisition of AstraZeneca would add to the $127 billion of mergers in the pharmaceuticals sector this year, according to data compiled by Bloomberg. An industrywide recalibration that has been building since 2011 reached a peak last week with a flurry of activity by GlaxoSmithKline Plc, Novartis AG and Valeant Pharmaceuticals International Inc. (VRX)

AstraZeneca has no immediate comment, spokeswoman Esra Erkal-Paler said in a telephone interview today. The company is in the process of reviewing Pfizer’s statement, she said, without elaborating further.

New Drugs

The combination of Pfizer and AstraZeneca would create the largest health-care company by revenue, based on trailing 12-month financials, a position it may lose as the U.K. company loses $2.5 billion of sales by 2017, Sam Fazeli, senior analyst for pharmaceuticals at Bloomberg Industries wrote last week.

A deal with AstraZeneca would help Pfizer add early-stage drugs in a field of cancer treatments that use the body’s own immune cells to recognize and attack cancer. AstraZeneca in January announced an agreement with Immunocore Ltd. to develop new treatments that use immune cells, and it also has several of its own immune-based drugs being tested in multiple cancers.

Many of the largest drugmakers face a wave of patent expirations that are cutting billions of dollars from their top lines, forcing them to look for new therapies. Pfizer has reorganized its business over the past three years, shuttering some research projects and emphasizing others. Sales are projected to climb at a compound annual rate of 0.5 percent over the next five years, trailing the median rate of 2.4 percent for its closest peers, estimates compiled by Bloomberg show.

Latest Deals

Valeant this month offered to buy Allergan Inc., maker of the Botox wrinkle treatment, in a cash-and-stock deal valued at about $45.7 billion. Novartis AG this month agreed to buy London-based GlaxoSmithKline Plc (GSK)’s cancer drugs for as much as $16 billion while selling most of the Swiss company’s vaccines division to Glaxo for $7.1 billion and its animal-health unit to Eli Lilly & Co. for $5.4 billion.

AstraZeneca’s London-listed shares closed at 4,080 pence on April 25 and the stock has gained 14 percent this year. Pfizer closed at $30.75 in the U.S. last week, up 0.4 percent this year. The average premium for pharmaceutical takeovers of at least $1 billion was 30 percent over the past five years, data compiled by Bloomberg show.