Aberrations within the PI3K/AKT signaling axis are frequently observed in numerous cancer types, highlighting the relevance of these pathways in cancer physiology and pathology. However, therapeutic interventions employing AKT inhibitors often suffer from limitations associated with target selectivity, efficacy, or dose-limiting effects. Here we present the first crystal structure of autoinhibited AKT1 in complex with the covalent-allosteric inhibitor borussertib, providing critical insights into the structural basis of AKT1 inhibition by this unique class of compounds. Comprehensive biological and preclinical evaluation of borussertib in cancer-related model systems demonstrated a strong anti-proliferative activity in cancer cell lines harboring genetic alterations within the PTEN, PI3K, and RAS signaling pathways. Furthermore, borussertib displayed antitumor activity in combination with the MEK inhibitor trametinib in patient-derived xenograft models of mutant KRAS pancreatic and colon cancer. Significance: Borussertib, a first-in-class covalent-allosteric AKT inhibitor, displays antitumor activity in combination with the MEK inhibitor trametinib in patient-derived xenograft models and provides a starting point for further pharmacokinetic/dynamic optimization.

Structure-based driven synthesis and biological evaluation provide innovative novel covalent-allosteric Akt inhibitors.

The protein kinase MKK7 is linked to neuronal development and the onset of cancer. The field, however, lacks high-quality functional probes that would allow for the dissection of its detailed functions. Against this background, we describe an effective covalent inhibitor of MKK7 based on the pyrazolo­pyrimidine scaffold.

We present inhibitors of drug resistant mutants of EGFR including T790M and C797S. In addition, we present the first X-ray crystal structures of covalent inhibitors in complex with C797S-mutated EGFR to gain insight into their binding mode.