United States securities and exchange commission logo June 8, 2023 John Umstead Chief Financial Officer G1 Therapeutics, Inc. 700 Park Offices Drive, Suite 200 Research Triangle Park, North Carolina 27709 Re: G1 Therapeutics, Inc. Form 10-K for the Fiscal Year Ended December 31, 2022 Filed March 1, 2023 File No. 001-38096 Dear John Umstead: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Life Sciences