AbbVie will pay $261.25 per share in cash and stock, a 13 percent premium to Pharmacyclics stock's closing price on Wednesday on the Nasdaq.
The deal will consist of about 58 percent cash and 42 percent AbbVie common stock. Pharmacyclics stockholders can elect cash, AbbVie stock or a combination, subject to proration, the company said in a statement.
"Imbruvica is not only complementary to AbbVie's oncology pipeline, it has demonstrated strong clinical efficacy across a broad range of hematologic malignancies," AbbVie's Chief Executive, Richard Gonzalez, said in a statement.
Sales of Imbruvica, which has U.S. approvals for four forms of blood cancer, are expected to touch $1 billion in the United States this year, Pharmacyclics has said earlier.
AbbVie said it expects to fund the transaction through a combination of existing cash, new debt and stock.