The Delaware Supreme Court has upheld the dismissal of a derivative suit targeting the board of AbbVie Inc. over an aborted buyout of Shire, which ended up costing the Chicago-based drugmaker more than $1.6 billion.

A three-judge panel of the high court Monday upheld, by order, a Chancery Court decision from July that dismissed the suit on demand futility grounds, finding that the directors did not face a substantial risk of liability for their role in scuttling the $55 million deal. The two-sentence order, signed by Justice Karen L. Valihura, affirmed on the basis of the Chancery Court’s July 10 ruling and did not detail any independent reasoning from the Supreme Court.