Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with few treatment options currently available for patients. Extensive remodeling of extracellular matrix (ECM) generates a highly fibrotic tumor landscape, which impairs therapeutic response. Polychemotherapy regimens including gemcitabine/Abraxane and FOLFIRINOX are the standard-of-care for PDAC patients to extend survival but can also affect ECM deposition and remodeling, which may further drive PDAC fibrosis. Focal Adhesion Kinase (FAK) is known to regulate ECM-feedback response and fibrosis in cancer, presenting multiple modalities to reduce fibrosis and enhance therapeutic efficacy in PDAC. Narmafotinib(AMP945) is a potent, orally bioavailable small molecule inhibitor of FAK, currently Narmafotinib is currently under clinical investigation in Phase Ib/IIa trials (AMP945-PC-201 [ACCENT, NCT05355298]) in combination with gemcitabine and Abraxane (nab-paclitaxel) in PDAC patients.
Here, we present pre-clinical data on the efficacy of narmafotinib, in mouse and patient-derived models of PDAC. Using(3D)-organotypic matrices we reveal that FAK inhibition via narmafotinib during stromal remodeling (or ‘priming’) reduces fibrosis, while also limiting subsequent PDAC invasion. Moreover, intravital imaging of a Fluorescence Resonance Energy Transfer (FRET) biosensor of FAK activity and a FUCCI cell cycle reporter confirms FAK inactivation in live PDAC in real time and an improvement in chemotherapeutic efficacy, respectively, upon narmafotinib administration in vivo. Lastly, long-term assessment of narmafotinib priming prior to gemcitabine/Abraxane or FOLFIRINOX chemotherapy in patient-derived (xenograft) models demonstrates that narmafotinib priming reduces PDAC metastasis, progression and extends survival in both settings. The potential utility of narmafotinib is further supported by Phase I safety data (ACTRN12620000894998) showing excellent safety, tolerability, and pharmacokinetic properties following oral administration in human volunteers. Collectively, our pre-clinical results using this Phase II drug combination, strongly support the clinical assessment of narmafotinib in combination with chemotherapy in pancreatic cancer, which is currently ongoing in Phase Ib/IIa clinical trials, assessing a pulse dosing regimen of narmafotinib in combination with gemcitabine and Abraxane as first-line therapy in patients with unresectable or metastatic pancreatic cancer and warrants future assessment of narmafotinib in human PDAC patients.