definiens: means a Small Molecule that:(a ) ( i ) was synthesized and/or assayed against the Target by PTI or Third Parties acting on behalf of PTIprior to the Effective Date, ( ii ) was synthesized and/or assayed intentionally against the Target by [COMPANY] Idec orThird Parties acting on behalf of [COMPANY] Idec prior to the Effective Date, or ( iii ) is synthesized and/or assayed againstthe Target by or on behalf of a Party in the course of performing activities under the Research Program, or is [ * * * ] ofany Small Molecule synthesized and/or assayed as described in ( i ), ( ii ) or ( iii ) above . For clarity, assaying describedin ( i ) and ( ii ) above will exclude [ * * * ] ; ( b ) modulates the activity of the Target as its primary and intended mechanism of action for therapeuticeffect ; and(c ) the IC50 for such chemical entity in the Target in vitro assay is less than or equal to [ * * * ] with [ * * * ] selectivity against the [ * * * ]