GenMark Sued by Holder Eyeing $1.8 Billion Roche Deal Challenge

A GenMark Diagnostics Inc. investor sued it in Delaware, seeking internal files to investigate allegations that its board succumbed to conflicts of interest in backing its $1.8 billion sale to Roche Holding AG—which was set to close Thursday—over a potentially superior offer.

The board’s close engagement with Roche during pre-deal talks and its “apparent indifference” to a rival suitor showing “strong interest” create “a credible basis to suspect” that “potential favoritism” led the directors to “short-circuit” the sales process to secure perks for themselves, the complaint says.

The lawsuit, filed late Wednesday in Delaware Chancery Court, cites “financial incentives” ...