US drugs giant Pfizer is digging into its deep pockets to boost its oncology portfolio. The New York-based company said it will pay $48 per share to acquire Array BioPharma, a US drug developer that has seen its shares soar recently on the back of positive clinical trials.

Array's share price has more than doubled since the start of this year, and Pfizer's offer represents a premium of 62% to the paper’s closing price of $29.59 on Jun. 14. The biotech’s stock surged again on news of the Pfizer deal, which the boards of both companies have approved.

The acquisition is Pfizer’s first major M&A move under the leadership of Albert Bourla, who became chief executive in January of this year after being promoted from chief operating officer, a position he held for just over a year.

Pfizer said it plans to finance the purchase, the biggest since its takeover of Medivation for $14.3 billion in 2016, with a combination of debt and cash. The US market’s largest pharmaceutical producer in terms of revenue expects the transaction to be accretive to earnings per share starting in 2022.

With Array, Pfizer will add two marketed drugs, MEK inhibitor Mektovi and BRAF inhibitor Braftovi, to its cancer portfolio. Approved as a combined treatment for melanoma, the duo also recently returned positive results in trials with metastatic colorectal cancer patients. When used in tandem with Eli Lilly’s and Merck KGaA’s Erbitux, it reportedly reduced the risk of death by 48%.

Along with Mektovi and Braftovi, Array has a number of out-licensed drugs that analysts expect to generate considerable royalties, including Vitrakvi, the first drug to get an initial FDA approval in tumors with a particular molecular feature regardless of their location, developed by a partnership of Loxo Oncology and Bayer.