WEE1 kinase inhibition to overcome acquired resistance to targeted therapies in colorectal cancer.

Molecular therapies targeting the EGFR/MAPK pathway have improved outcomes in colorectal cancer (CRC), yet acquired resistance remains a major clinical challenge. Oncogenic signaling can activate stress response pathways that sustain tumor survival under therapeutic pressure. Among these, the DNA damage response (DDR) maintains genomic integrity and may represent a targetable vulnerability in resistant tumors. To investigate this, we developed a preclinical platform of CRC models with acquired resistance to anti-EGFR agents ("ARes platform"). A targeted pharmacological screen of DDR inhibitors identified WEE1 kinase as a leading therapeutic candidate. Validation in xenograft models and patient-derived organoids confirmed that anti-EGFR-resistant CRCs retained, and in some cases increased, sensitivity to WEE1 inhibition. Mechanistically, resistant cells exhibited elevated DNA damage, heightened replication stress, and accelerated mitotic entry, culminating in cell death upon WEE1 blockade. These findings establish WEE1 as a promising therapeutic target in CRC with acquired resistance to EGFR inhibition and support the clinical evaluation of WEE1 inhibitors, alone or combined with DNA-damaging agents, for patients progressing on anti-EGFR-based therapies.