definiens: means the commercially reasonable efforts and resources that are of a substantially similarlevel of effort and resources with respect to the Development, obtaining of regulatory approvals and commercializationof drug candidates that Buyer, Parent and their Affiliates would typically exercise with respect to drug candidates ofsimilar commercial potential at a similar stage in their development or product lifecycle to that of a Product taking intoaccount all relevant factors at the time such efforts are expended, including, the safety and efficacy of such Product, the risks inherent in the Development and commercialization of the Product, its competitiveness compared toalternative products, the proprietary position of the Product ( including scope and duration of relevant Patents ), thescope of marketing approval, the regulatory status of the Product, whether the Product is subject to a clinical hold, recall or market withdrawal and the anticipated profitability of the Product ; it being understood that ( a ) the payment ofMilestone Payments shall be de facto evidence that Buyer has exercised Diligent Efforts ; and ( b ) the failure toachieve any Milestone Event or make any Milestone Payment shall not in itself constitute evidence that DiligentEfforts were not exercised