Prosecution and Maintenance of Patent Rights (a) Ardelyx shall be responsible for the preparation, filing, prosecution (including without limitation conducting any interferences, oppositions, reissue proceedings and reexaminations) and maintenance of the Listed Patents, unless and until Sanofi has exercised the Option to Continue and Ardelyx has received the Continuation Milestone. Ardelyx agrees to prosecute and maintain the Listed Patents in those countries set forth on Exhibit C. A detail of Patent Costs incurred by Ardelyx in prosecuting and maintaining the Listed Patents prior to the Effective Date is set forth on Exhibit B; provided, however, that the costs and expenses set forth on Exhibit B do not include those costs and expenses incurred by Ardelyx in the drafting and filing of the Listed Patents. Ardelyx will bear the [***] of Patent Costs after the Effective Date and prior to Sanofi’s exercise of the Option to Continue. After Ardelyx has paid such amount, Sanofi shall reimburse Ardelyx for any additional Patent Costs incurred by Ardelyx after the Effective Date during the Term until such time as Sanofi exercises the Option to Continue and Ardelyx has received the Continuation Milestone. Ardelyx shall submit invoices to Sanofi at the beginning of each Calendar Quarter, which invoice shall detail the Patent Costs in the previous Calendar Quarter and, if applicable, include all copies of invoices from outside counsel. Sanofi shall pay each invoice within thirty (30) days of its receipt thereof. During the time that Ardelyx is responsible for the prosecution of the Listed Patents, Ardelyx shall provide Sanofi with advance copies of, and a reasonable opportunity to comment upon, proposed patent filings, related prosecution strategies and proposed correspondence with patent officials or other Third Parties relating to any Listed Patents. Ardelyx, in the course of such activities, will consider comments received from Sanofi with respect to such proposed filings, strategies and correspondence in good faith and will not unreasonably reject such comments to the extent such comments could reasonably be deemed to impact Ardelyx Compounds. In any event, Ardelyx will not finally abandon any claims and will not limit any claims that are specific to Ardelyx Compounds without Sanofi’s prior written consent. Ardelyx shall cooperate to assist Sanofi in assuming the prosecution and maintenance of the Listed Patents as provided by Section 8.4(i), including by transferring to Sanofi the patent files associated with such Licensed Products and providing any other information reasonably requested by Sanofi and access to the relevant inventors.