definiens: means, with respect to : ( a ) each Program other than the Pain 2 Program, the set of up to three ( 3 ) Collaboration Compounds comprised of a Development Candidate and up to two ( 2 ) Backup Compounds or one ( I ) Backup Compound and one ( I ) Follow - On Compound ; or ( b ) the Pain 2 Program, the set of up to five ( 5 ) Collaboration Compounds comprised of ( i ) a Development Candidate and up to two ( 2 ) Backup Compounds or one ( I ) Backup Compound and one ( I ) Follow - On Compound, in each case for a particular Pain Sub - Indication, and ( ii ) up to two ( 2 ) Follow - On Compounds, with each such Follow - On Compound under this clause ( ii ) to be for a different Pain Sub - Indication from each other and from the Development Candidate . In each case above, such Backup Compounds or Follow - On Compounds shall be pursued pursuant to a strategy contemplated by the Research Plan(s ) and approved by the JSC