Cymirafen is a novel antibody-drug conjugate (ADC) from the University of California that targets leucine-rich repeat-containing G-protein coupled receptor 4 (LGR4)/LGR5/LGR6 and is composed of a potent cytotoxic payload, monomethyl auristatin E (MMAE), plus an Fc domain fused to the receptor binding domain of RSPO1.