definiens: means any Antibody that ( a ) specifically binds CD33 and a principal therapeutic mechanism ofaction of which is mediated as a result of such binding and ( b ) is claimed in the Existing Patents or Licensor Program Patents or made by oron behalf of Licensor or its Affiliates under this Agreement . Licensed CD33 Antibody expressly includes the Antibody known by Licensor asAL003 and all back - ups to AL003 described on Schedule 1.127 . For clarity, bispecific and multispecific Antibodies with at least one of theirbinding specificities and principal therapeutic mechanisms of action ( as described above ) directed to CD33 and that are claimed in theExisting Patents, Licensor Program Patents, or made by or on behalf of Licensor or its Affiliates under this Agreement shall also beconsidered Licensed CD33 Antibodies