BAY-707 is a substrate-competitive, highly potent and selective inhibitor of MTH1. Despite superior cellular target engagement and pharmacokinetic properties, inhibition of MTH1 with BAY-707 resulted in a clear lack of in vitro or in vivo anticancer efficacy either in mono- or in combination therapies.
DKFZ-251 is a potent inhibitor of kallikrein-related peptidase 6 with on-target cellular activity. DKFZ-251 demonstrated good selectivity for KLK6 compared to other KLKs, and on-target activity in a cellular assay.