This study aims to determine the safety, effectiveness and appropriate dose level of the combination of the medicine BGB-3245 and panitumumab targeted therapy in people with advanced or metastatic RAS mutant bowel or pancreatic ductal cancersA Phase 1b, Open-Label, Dose Escalation and Expansion Study to Investigate the Safety, Pharmacokinetics, and Antitumor Activity of BGB-3245 With Panitumumab in Patients With Advanced or Metastatic RAS Mutant Colorectal and Pancreatic Ductal Cancers

Exclusion

1. Participants receiving cancer therapy (chemotherapy or other systemic anticancer therapies, immunotherapy, radiation therapy, or surgery) at the time of Cycle 1 Day 1.
2. Active infection requiring systemic treatment at the start of the study treatment.
3. Clinically significant cardiovascular disease and / or events within 6 months of signing the informed consent form.
4. Participants with toxicities that have not recovered to Grade ≤1 or stabilized and those Grade 2 toxicities listed as permitted in other eligibility criteria.
5. Participants with a history of pneumonitis or interstitial lung disease.
6. Participants with immune-related toxicities that have not resolved with appropriate management.
7. History or presence of gastrointestinal disease or other condition known to interfere with the absorption of drugs.
8. History of ulcerative colitis or Crohn's disease or protracted and ongoing immune-mediated diarrhea from prior checkpoint inhibitor use.
9. History of corneal perforation, keratitis, or severe dry eye.
10. Current evidence of symptomatic central nervous system metastases, leptomeningeal carcinomatosis, or untreated spinal cord compression.
11. Any active malignancy ≤3 years before Cycle 1 Day 1 except for the specific cancer under investigation in this study and any localized or noninvasive cancer that has been treated curatively.
12. Known hypersensitivity to rapidly accelerated fibrosarcoma (RAF) inhibitors, anti-epidermal growth factor receptor (EGFR) monoclonal antibodies, or their excipients.
13. Any known history of Grade ≥3 toxicity lasting >14 days from another RAF, mitogen activated protein kinase, extracellular signal-regulated kinase, or anti-EGFR antibody inhibitor requiring discontinuation of treatment from these drugs.
14. Receiving any treatment with a strong cytochrome P450 3A4 (CYP3A4) inhibitor or inducer ≤14 days (or 5 half-lives, whichever is longer) before Cycle 1 Day 1 and until completion of dosing with BGB-3245 for at least 5 half-lives.

NOTE: Other protocol defined Inclusion/Exclusion criteria apply. Summary of key criteria provided.