The substance patent protecting its cholesterol fighter is valid.

• AstraZeneca profits climb by nearly a third

A US District Court has found that AstraZeneca’s substance patent protecting multibillion-dollar cholesterol fighter Crestor is valid and enforceable, the company said Wednesday in a statement that could only be described as a cry of joy.

The company stock rallied 10 percent in Stockholm after the announcement.

The ruling is a great victory in the Anglo-Swedish pharmaceuticals giant's effort to ward off early generic competition.

"Most in the investment community felt AstraZeneca would very likely win, but given how devastating a loss would ... have been, actually securing a favorable ruling removes an overhang," Tim Anderson, an Bernstein analyst, wrote in a research note.

Last year the drug had U.S. sales of 2.1 billion dollar and global sales of 4.5 billion dollar.