definiens: means : ( a ) an active pharmaceutical ingredient or drug substance comprising GRN163, inunconjugated or any conjugated form ; or ( b ) a Bioequivalent of such pharmaceutical ingredient or drug substancedescribed in clause ( a ) ( e.g., a homologous oligonucleotide having substantial identity to the oligonucleotide sequenceof GRN163 having pharmaceutically or pharmacologically equivalent telomerase inhibitory activity, or any otherbiological activity that is ( at the relevant time ) recognized by the FDA or another Regulatory Authority as thepredominant or primary mechanism of action in humans, such as may be reflected in associated product labelling orpackage insert information at the relevant time ) as GRN163 in unconjugated or conjugated form ; or ( c ) a salt, hydrate, solvate, polymorph, stereoisomer, prodrug, or metabolite of any of the foregoing pharmaceutical ingredients or drugsubstances described in clauses ( a ) or ( b )