LEAP THERAPEUTICS, INC.

(b) Lead Investor Agreement

Pursuant to the terms of the Lead Investor Agreement (as defined herein), the Company has granted Winklevoss Capital, as Lead Investor, the right to nominate two directors to the Board (the “Investor Designees”), one of whom shall act as chair of the Board. For so long as the Lead Investor continues to beneficially own at least 16.7% of the Common Stock, the Lead Investor shall have the right to designate two Investor Designees, one of whom shall also be chair of the Board, and for so long as the Lead Investor continues to beneficially own at least 8.33% but less than 16.7% of the Common Stock, the Lead Investor shall have the right to designate one Investor Designee, who shall also be the chair of the Board. The Company has agreed to use its reasonable best efforts to cause the Investor Designees to be elected to the Board (including recommending that the Company’s stockholders vote in favor of the election of the Investor Designees). The Lead Investor Agreement also contains customary representations and warranties, confidentiality provisions and limitations on liability.

(c) Rule 10b5-1 Trading Plan

During the three months ended September 30, 2025, no director or officer of the Company adopted orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.