With Teva Pharmaceutical Industries' announcement Monday of its $40.5 billion acquisition of Allergan's generic drug business, a third drug company, Mylan NV, no longer faces a potential hostile takeover by Teva. But even as the transactional battle cools off, Mylan remains embroiled in litigation connected to the tactics it used to fend off the hostile bid.

Beyond announcing the Allergan deal Monday, Israel-based Teva said separately that it would back off a proposal to buy Mylan. Teva's been attempting, unsuccessfully, since April to complete the Mylan takeover. Mylan, for its part, has taken several tactical steps over the past several months to contest Teva's potential takeover—moves that have put the company on opposing sides of a pair of lawsuits pending in a Pittsburgh federal court.

On one front, Mylan filed a lawsuit in May seeking to block Teva's former transactional lawyers at Kirkland & Ellis from continuing to advise on the hostile acquisition attempts. The lawsuit alleged that Kirkland had previously done some work for Mylan, making its representation of Teva a conflict of interest. Wilson, Sonsini, Goodrich & Rosati's Michael Sommer represents Mylan in the litigation, while Kirkland tapped a defense team led by Gibson, Dunn & Crutcher's Kevin Rosen.