Winston & Strawn must face a $2.5 million malpractice suit from former shareholders of pharmaceutical company Biosynexus for allegedly botching the 2005 sale of the company, a Manhattan judge has ruled.

In OrbiMed v. Winston & Strawn, 13708/10, Supreme Court Justice Judith J. Gische (See Profile) allowed to go forward two of three claims in the suit, which was filed by medical investment firm OrbiMed on behalf of all Biosynexus’ former shareholders. The shareholders claimed Winston & Strawn failed to disclose details of Biosynexus’ licensing agreements while the shareholders were negotiating the company’s sale to the hedge fund QVT Fund LP. As a result of that alleged failure, the shareholders claim they spent $2.5 million suing QVT in order to get paid in full for the $56 million sale.