Inhibitors of pro-HGF activation overcome resistance to anti-EGFR therapy

ABSTRACTFactors in the tumor microenvironment promote the growth of tumors and impact their response to therapyHepatocyte Growth FactorHGFfrequently upregulated in the tumor microenvironmentactivates the receptor tyrosine kinase MET expressed on cancer cells which contributes to tumor progression and confers therapeutic resistanceBecause cancer cells become addicted to HGF MET signalingboth HGF and MET are valid therapeutic targetsAlthough various agents have been developed to target HGF MET signalingthere are currently no approved drugs that would inhibit HGF or block MET activity specificallyThe rate limiting step in the HGF MET signaling is the proteolytic processing of pro HGF to active HGF by one or more of the three serine proteasesmatriptasehepsin or HGF activatorHGFAWe have developed the first small molecule inhibitors of HGF activation which mimic the activity of the endogenous inhibitors of HGF activationHAIand HAIThese triplex inhibitors of hepsinmatriptase and HGFA are from two chemical series of ketobenzothiazoleskbtsand cyclic urea benzamidinescubsWe confirmed that these inhibitors block HGF activation and thus refer to them as synthetic HAIssHAIsWe have shown that sHAIs inhibit MET signaling and prevent HGF mediated scatteringmigration and survival in multiple types of cancer cellsWe have shown that the lead sHAIPTXovercomes resistance to EGFR inhibitors in vitro and impedes HGF dependent growth of lung cancer in vivoThe goal of this application is to continue lead optimization and to confirm its in vivo activity in colon cancerWe will show that PTXblocks HGF mediated growth and metastasis of colon cancer and prevents overcomes resistance to EGFR inhibitors in vivoOur specific aims areAimTo optimize sHAIs for improved metabolic stability and pharmacokineticPKpropertiesTo rationally designsynthesize and evaluate analogues for their HGFAmatriptase and hepsin inhibitory activityacyclic peptide and bunnatural amino acid containing kbt InhibitorscTo determine the in vitro metabolic stabilityphysical properties and in vivo PK of lead sHAIsAimTo demonstrate that PTXblocks HGF dependent tumor growth metastasis and overcomes resistance to EGFR inhibitors in colon canceraTo show that PTXblocks tumor growth and metastasis in two syngeneic colon cancer models that are driven by HGFCTand MCbTo confirm that PTXprevents HGF dependent primary resistance and overcomes tumor microenvironment mediated therapeutic resistance to EGFR targeting agents in vivoCollectivelythese studies will provide a rationale to include sHAIs into treatment regimens to block HGFdependent tumor progression and to prevent or to overcome HGF dependent resistance to targeted therapysignificantly improving the outcome of colon cancer patients Narrative At ProteXase Therapeutics we have developed the first small molecule inhibitors of HGF activationwhich we termed Vynthetic HGF Activator InhibitorssHAIsWe have shown that sHAIs block HGF activationhave potent anticancer activity and overcome resistance to EGFR targeting drugs in colon cancer cell linesThe objective of this project is to confirm that lead compoundVDQG PTXblock tumor progression and prevent resistance to targeted therapy in mouse models of colon cancera necessary step before we can validate the activity of sHAIs in clinical trials!