Abstract Metastatic uveal melanoma (mUM) is an aggressive cancer with limited treatment options; 85−90% of tumors harbor activating GNAQ and GNA11 mutations. Uveal melanoma cells also express PMEL (also known as PMEL17 or gp100), a melanocyte lineage antigen. DYP688, a novel biology-matched antibody−drug conjugate, binds surface PMEL and delivers the potent Gαq/Gα11 (Gq/11) inhibitor SDZ475 as pay...