Aprea Therapeutics announces preclinical data on its ATRN-1051 candidate

Aprea Therapeutics announced updated preclinical data supporting development of the Company’s WEE1 inhibitor candidate, ATRN-1051, for the treatment of ovarian cancer. The preclinical and in vitro data suggest that the selective properties of ATRN-1051 may make it a more efficacious cancer therapy than the other WEE1 inhibitors in development. Importantly, ATRN-1051 is a highly potent and selective inhibitor of WEE1 that does not significantly affect off-target PLK1, PLK2 and PLK3, a family of kinases that promote M phase entry, a critical phase in the cell cycle. Such off-targeting of the PLK family has been a challenge to other WEE1 inhibitors in the class. Evidence generated by Aprea suggests that off-target inhibition of PLK1 substantially limits the ability of WEE1 inhibitors to cause genotoxicity, the proposed mechanism by which WEE1 inhibitors act as cancer therapeutics. The preclinical research of ATRN-1051 in ovarian cancer also shows an increased expression of cyclin E1, or CCNE1. CCNE1 amplification, which is associated with platinum resistance and poor survival, has been shown to be a reliable predictive biomarker of response to WEE1 inhibition. As part of the preclinical studies with ATRN-1051, the Company conducted cell culture and CDX mouse model studies using the CCNE1-normal and CCNE1-amplified ovarian cancer cell lines to show that low doses of ATRN-1051 completely suppress the growth of CCNE1-amplified ovarian cancer cells and tumors