This invention relates to novel peptidomimetic compounds which are useful as linkers of antibody-drug conjugates (ADC). This invention also relates to ADCs containing peptidomimetic linkers and anthracycline derivatives. It is contemplated that the ADC of the present invention may be used to treat various diseases or disorders, e.g.characterised by the overexpression of a tumour antigen.L'invention concerne des éléments de liaison peptidomimétiques et des conjugués anticorps-médicaments de ceux-ci, des compositions pharmaceutiques les contenant, et leur utilisation en thérapie pour la prévention ou le traitement du cancer.