Anti-GPRC5A antibodies and their uses

Abstract

The objective of this invention is to provide an anti-GPRC5A antibody that binds to GPRC5A on the cell surface, and to provide an antibody-drug complex comprising the antibody or a pharmaceutical composition comprising the antibody-drug complex. The solution involves immunizing mice with a cell line expressing human GPRC5A or human GPRC5A protein to obtain a novel mouse anti-GPRC5A antibody (Example 1). Furthermore, based on the sequence information of the mouse antibody, nine types of human chimeric anti-GPRC5A antibodies and humanized anti-GPRC5A antibodies were obtained from the anti-GPRC5A antibody (Examples 4 and 6). Furthermore, using the anti-GPRC5A antibody to prepare an antibody-drug complex (ADC), it was found that the ADC binds to cancer cells expressing GPRC5A and has a toxic effect on these cells (Examples 8 and 9). In addition, the human chimeric anti-GPRC5A antibody-drug complex showed anti-tumor effects in a mouse subcutaneous xenograft model (Example 10). The above results confirm that the novel human chimeric anti-GPRC5A antibody is useful for targeting pharmacologically active substances to cells expressing GPRC5A.

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