On June 6, 2023 (the Closing Date), G1 Therapeutics, Inc. (the Company), as borrower, and Hercules Capital, Inc. and certain of its affiliates (collectively, the Lender) entered into a fifth amendment (the Fifth Amendment) to amend that certain loan and security agreement, dated as of May 29, 2020, as amended by the First Amendment to Loan and Security Agreement, dated as of March 31, 2021 (the First Amendment), the Second Amendment to Loan and Security Agreement, dated as of November 1, 2021 (the Second Amendment), the Third Amendment to Loan and Security Agreement, dated as of June 24, 2022 (the Third Amendment), and the Fourth Amendment to Loan and Security Agreement dated as of November 1, 2022 (the Fourth Amendment; the loan and security agreement, as amended by the First Amendment, the Second Amendment, the Third Amendment, the Fourth Amendment and the Fifth Amendment, the Loan and Security Agreement), under which the Lender has agreed to lend the company up to $75.0 million, subject to specified conditions. The total loan amount outstanding upon closing of the Fifth Amendment is $50.0 million. The Fifth Amendment eliminates advances under Tranches 2 and 3 and increases the advance available under Tranche 4 from $15.0 million to $25.0 million and extends the time for drawing the Tranche 4 Advance from June 30, 2024 to December 15, 2024.