Birmingham-based Wragge has advised a Japanese giant on a "snail" drug.
The law firm's Life Sciences team led by partner Patrick Duxbury is acting for Eisai on its acquisition of the European rights to pain suppressant Prialt from US group Elan Corporation.
Prialt is the synthetic equivalent of a peptide found in a marine snail.
Elan will receive $50 million on completion plus a further $50 million in launch and milestone payments.
The Wragge & Co team comprised director and life sciences specialist Luke Kempton, corporate partner Baljit Chohan, antitrust partner Bernardine Adkins and antitrust solicitor Andrew
Maxwell. They worked closely with Eisai's European general counsel and director of compliance, Simon Thomas, and legal director, Kenta Takahashi. Clifford Chance partner Joel Ziff and a team comprising Ron Moscona and Robin Bolivar advised Elan.
Eisai is a global pharmaceutical company headquartered in Tokyo.
It employs more than 8,000 people across its businesses in Asia, Europe and the US.
It is the first major deal Wragge & Co has handled for Eisai, who instructed the firm following a recommendation from an existing life sciences client.
The Life Sciences Team has completed deals for Unilever, Astex and 3i.