Abbvie has completed its $21 billion buyout of Pharmacyclics. The buyout adds another major revenue producer to Abbvie’s portfolio, which already includes the world’s top-selling drug, Humira. The deal gives the North Chicago drugmaker Imbruvica, a blood cancer treatment that Pharmacyclics makes and then markets with Johnson & Johnson’s Janssen Biotech.

Pharmacyclics, Inc. will become a subsidiary of Abbvie and operate from its Sunnyvale, California headquarters.

The buyout comes months after Abbvie Inc. scuttled a $55 billion deal to buy another drugmaker, Shire, after the U.S. government put in place new limitations on the tax benefits of reincorporating overseas. Abbvie would have reincorporated on the British island of Jersey, where Shire is incorporated.