This study is evaluating how safe, tolerable and effective administering a new targeted therapy (called ZN-c3) with an existing combination of targeted therapies (encorafenib and cetuximab) is in adults with metastatic BRAF V600E mutant colorectal cancer who have previously had treatmentA Phase 1/2, Open-Label, Multi-Center Study of ZN-c3 Administered in Combination With Encorafenib and Cetuximab in Adults With Metastatic Colorectal Cancer

Exclusion

• Documented clinical disease progression or radiographic disease progression during the screening period
• Leptomeningeal disease.
• Symptomatic brain metastasis.
• Presence of acute or chronic pancreatitis.
• Unable to swallow, retain, and absorb oral medications.
• Clinically significant cardiovascular diseases
• Evidence of active noninfectious pneumonitis.
• Evidence of active and uncontrolled bacterial or viral infection, within 2 weeks prior to start of any of the study interventions
• Participants with known positivity for HIV
• Active hepatitis B or hepatitis C infection
• Concurrent or previous other malignancy within 2 years of study entry
• Has had an allogeneic tissue/solid organ transplant
• Pregnant or females of childbearing potential who have a positive β-hCG laboratory test result within 14 days prior to enrollment or is breastfeeding