LY3214996 and Cetuximab Alone or in Combination With Abemaciclib for the Treatment of Unresectable or Metastatic Colorectal Cancer

Inclusion Criteria: * Provision of signed Informed Consent prior to any screening procedures being performed. The informed consent process will be conducted in accordance with MD Anderson Office of Clinical Research SOP 04 and as indicated in Appendix 2. * Age ≥18 years at the time of informed consent. * Histologically (or cytologically) confirmed diagnosis of adenocarcinoma of the colon or rectum, with clinical confirmation of unresectable and/or metastatic disease that is measureable according to RECIST1.1 criteria. * Baseline tissue-based KRAS, NRAS, EGFR, BRAF wild-type tumor. If MEK1 was tested, must be wild-type tumor * Prior treatment with at least one systemic chemotherapy regimen for mCRC, or recurrence/progression with development of unresectable or metastatic disease within 6 months of adjuvant chemotherapy for resected colorectal cancer. * Participants who received chemotherapy must have recovered (Common Terminology Criteria for Adverse Events \[CTCAE\] Grade .1) from the acute effects of chemotherapy except for residual alopecia or Grade 2 peripheral neuropathy prior to randomization. A washout period of at least 21 days is required between last chemotherapy dose and randomization (provided the participant did not receive radiotherapy). * Participants who received radiotherapy must have completed and fully recovered from the acute effects of radiotherapy. A washout period of at least 14 days is required between end of radiotherapy and randomization * Left-sided…