X0306 4 2020-05-18 0 0001564824 Allakos Inc. ALLK 0001207792 MORE ROBERT J ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 0 1 member - potential 10% group Common Stock 2020-05-18 4 S 0 6432 71.01 D 5106 D Common Stock 2020-05-18 4 S 0 4506 72.25 D 600 D Common Stock 2020-05-18 4 S 0 600 72.74 D 0 D Common Stock 2557377 I See Footnote The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.46 - $71.38, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.68 - $72.65, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $72.72 - $72.76, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. These shares are directly held by Alta Partners NextGen Fund I L.P. ("APNG I"). Alta Partners NextGen Fund I Management, LLC ("APNG I Management") is the general partner of APNG I. The Reporting Person is one of three managing directors of APNG I Management and, as such, has voting and investment control with respect to the shares held by APNG I. The Reporting Person disclaims beneficial ownership of all shares held by APNG I, except to the extent of his pecuniary interest therein. /s/ Robert J. More 2020-05-20