Licensee Enforcement. In the event that either Licensee or Merck becomes aware of any alleged or threatened commercially material infringement in a country in the Territory of any issued patent within the Compound Patent Rights or Joint Patent Rights, it will notify the other Party in writing to that effect. Licensee shall have the first right (but not the obligation) to enforce any such Compound Patent Right or Joint Patent Right against any such infringer or alleged infringer, at its own expense, and control, and litigate and settle, such suit as set forth herein. Merck shall reasonably cooperate in any such suit at Licensee’s expense; and where necessary, Merck shall join in, or be named as a necessary party to, such suit. Licensee shall not enter into any settlement of any claim described in this Section 8.04(a) that, in the reasonable judgment of Merck would violate any law or regulation, admits to the invalidity or unenforceability of the Compound Patent Rights or Joint Patent Rights, incurs any financial liability on the part of Merck, requires an admission of liability, wrongdoing, or fault on the party of Merck, without Merck’s prior written consent (in each case, such consent not to be unreasonably withheld). Merck shall have the right, prior to commencement of the trial, suit or action brought by Licensee, to join any such suit or action, and in such event shall pay one-half of the costs of such suit or action.