UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 Commission File Number 001-38096 G1 THERAPEUTICS, INC. (Exact name of Registrant as specified in its Charter) Delaware 26-3648180 ( State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 700 Park Offices Drive, Suite 200 Research Triangle Park, ...