X0306 4 2017-07-26 1 0001370053 ANAPTYSBIO INC ANAB 0001318999 Avalon Ventures VII L P 1134 KLINE STREET LA JOLLA CA 92037 0 0 1 0 0001380392 AVALON VENTURES VII GP, LLC C/O AVALON VENTURES VII, L.P. 1134 KLINE STREET LA JOLLA CA 0 0 1 1 See Remarks 0001311643 Kinsella Kevin J C/O AVALON VENTURES VII, L.P. 1134 KLINE STREET LA JOLLA CA 92037 0 0 1 1 See Remarks 0001695652 Tomlin Stephen Lawrence C/O AVALON VENTURES VII, L.P. 1134 KLINE STREET LA JOLLA CA 92037 0 0 1 1 See Remarks Common Stock 2017-07-26 4 J 0 399987 0.00 D 1636945 I See footnote Common Stock 2017-07-26 4 J 0 37040 0.00 A 37040 I See footnote Common Stock 2017-07-26 4 S 0 37040 24.35 D 0 I See footnote Represents a pro-rata in-kind distribution of Common Stock by Avalon Ventures VII, L.P. effected on July 26, 2017 without consideration to its limited partners and to its general partner, Avalon Ventures VII GP, LLC. Represents the receipt by Avalon Ventures VII GP, LLC, the general partner of Avalon Ventures VII, L.P., of its pro-rata portion of the in-kind distribution described in footnote 1. Represents the open-market sale by Avalon Ventures VII GP, LLC, the general partner of Avalon Ventures VII, L.P., of the Common Stock received as a result of the in-kind distribution described in footnote 1. Avalon Ventures VII GP, LLC is the general partner of Avalon Ventures VII, L.P. The managing members of Avalon Ventures VII GP, LLC are Kevin J. Kinsella and Stephen L. Tomlin. As a result of the transactions reported herein, none of the Reporting Owners will beneficially own 10% or greater of the outstanding Common Stock or otherwise be subject to Section 16 (except as expressly provided by Section 16 once reporting status has ended). Avalon Ventures VII, L.P., Avalon Ventures VII GP, LLC, Kevin Kinsella, Stephen Tomlin, By: /s/ Tighe Reardon, Attorney-in-Fact 2017-07-27