CD228 (melanotransferrin / MFI2, membrane-bound form)

Class

CD228-directed antibody-drug conjugate (MMAE payload)

Pathway

Antibody selectively binds membrane-bound CD228 on tumor cells and delivers a cleavable-linker MMAE cytotoxic payload

CD228, also known as melanotransferrin, is a membrane-bound glycoprotein related to the transferrin family of iron-transport proteins. It is expressed at markedly higher levels on the surface of certain tumor cells, most notably melanoma, than on most normal tissues, making it a candidate for antibody-based tumor targeting. This mechanism uses an antibody-drug conjugate (ADC) approach: a monoclonal antibody recognizes membrane-bound CD228 and is chemically linked to a potent microtubule-disrupting payload, monomethyl auristatin E (MMAE), via a linker designed to remain stable in circulation but release the drug once inside the target cell. The rationale is to concentrate a cytotoxic agent too systemically toxic to give as a free drug within tumor cells while sparing normal tissue that lacks the antigen. This general strategy—pairing a tumor-selective surface marker with a potent payload—is broadly relevant across solid tumors where an antigen shows a favorable ratio of tumor to normal tissue expression, with melanoma being the disease context most closely associated with CD228 biology. The approach reflects a wider principle in oncology: converting a nonspecific cytotoxic agent into a tumor-directed therapy through selective antibody delivery.