X0306 4 2017-03-17 0001029125 Sun BioPharma, Inc. SNBP 0001133026 KAYSEN DAVID B 712 VISTA BLVD #305 WACONIA MN 55387 1 1 President and CEO Employee Stock Option (right to buy) 1.51 2017-03-17 4 A 0 248000 0 A 2026-12-12 Common Stock 248000 424000 D On December 12, 2016, the reporting person was granted an option to purchase up to 800,000 shares of common stock. The option became exercisable with respect to 176,000 shares as of December 12, 2016 and with respect to an additional 248,000 shares as of March 17, 2017. The remainder is subject to vesting proportionately based on cash proceeds received by, or contractually obligated to be remitted to, the issuer after June 1, 2016 and before December 31, 2018 from any transaction, excluding certain internal operating-related cash flows. Option vested with respect to 248,000 additional shares pursuant to certification by issuer compensation committee. /s/ Joshua L. Colburn, Attorney-in-fact for David B. Kaysen 2017-03-21