A targeted combination therapy achieves effective pancreatic cancer regression and prevents tumor resistance

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• Pancreatic ductal adenocarcinoma (PDAC) exhibits poor survival rates, with current therapies limited by rapid tumor resistance.
• RAS inhibitors show promise but face challenges due to acquired resistance mechanisms.

Purpose of the Study:

• To investigate the efficacy of targeting multiple signaling nodes in KRAS-mutated PDAC.
• To evaluate a combination therapy approach to overcome tumor resistance and achieve durable responses.

Main Methods:

• Genetic ablation of RAF1, EGFR, and STAT3 nodes in orthotopic PDAC models.
• Pharmacological inhibition of KRAS (daraxonrasib), EGFR (afatinib), and STAT3 (SD36) in preclinical PDAC models.
• Assessment of tumor regression, resistance development, and tolerability in various PDAC models including patient-derived xenografts (PDX).

Main Results:

• Genetic ablation of RAF1, EGFR, and STAT3 led to complete and permanent PDAC regression.
• Combination therapy with daraxonrasib, afatinib, and SD36 induced complete PDAC tumor regression without resistance for over 200 days.
• The combination therapy demonstrated significant efficacy in genetically engineered mouse models and PDX models, with no observed relapses and good tolerability.

Conclusions:

• Targeting KRAS, EGFR, and STAT3 simultaneously represents a potent therapeutic strategy for PDAC.
• This combination therapy shows potential for durable tumor regression and overcoming resistance in PDAC.
• Results support the development of clinical trials for this novel combination therapy in PDAC patients.