X0306 4 2018-07-30 0 0001509745 LEAP THERAPEUTICS, INC. LPTX 0001262326 Mirabelli Christopher C/O LEAP THERAPEUTICS, INC. 47 THORNDIKE STREET SUITE B1-1 CAMBRIDGE MA 02141 1 1 1 0 CEO, President and COB Warrant (Right to Buy) 6.085 2018-07-30 4 J 0 21369 0 A 2017-11-14 2024-11-14 Common Stock 21369 21369 I See Footnotes Pro rata distribution from HealthCare Ventures IX, L.P. ("HCV IX") to its limited partner, Nine Capital Partners, LLC. Christopher K. Mirabelli, Douglas E. Onsi and Augustine Lawlor are the Managing Members of Nine Capital Partners, LLC, and as such, beneficially own and share voting and dispositive power with respect to all of the securities owned by Nine Capital Partners, LLC. Dr. Mirabelli disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest in these securities. The reporting person is also (i) a Managing Director of HealthCare Partners IX, LLC, which is the General Partner of HealthCare Partners IX, L.P., which is the General Partner of HCV IX, (ii) a Managing Director of HealthCare Partners VIII, LLC, which is the General Partner of HealthCare Partners VIII, L.P., which is the General Partner of HealthCare Ventures VIII, L.P. ("HCV VIII"), and (iii) a Managing Director of HCV Strategic LLC, which is the General Partner of HealthCare Ventures Strategic Fund, L.P. ("HCV SF"). HCV IX continues to hold 3,573,376 shares of common stock, HCV VIII continues to hold 2,618,406 shares of common stock, and HCV SF continues to hold 343,889 shares of common stock, representing 24.3%, 17.8%, and 2.3%, respectively, and 44.5% in the aggregate, of the outstanding shares of common stock. /s/ Douglas E. Onsi as attorney-in-fact for Christopher Mirabelli 2018-08-01