Antibodies can also be defined by both functional properties and structural features. It is possible to claim an antibody characterised by the sequences of both variable domains or CDRs with less than 100% sequence identity when combined with a clear functional feature.
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/g_ii_5_6_1_4.htm
Date retrieved: 17 May 2021