X0306 4 2020-01-22 0 0001564824 Allakos Inc. ALLK 0001736001 Alta Partners NextGen Fund I Management, LLC ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001399894 Alta Partners Management VIII, LLC ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001698110 Alta Partners NextGen Fund I, L.P. ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198321 CHAMPSI FARAH ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001674884 Hudson Peter A ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001207792 MORE ROBERT J ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198330 NOHRA GUY P ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001399763 Alta Partners VIII, L.P. ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198325 JANNEY DANIEL ONE EMBARCADERO CENTER SUITE 3700 SAN FRANCISCO CA 94111 1 0 1 0 Common Stock 2020-01-22 4 J 0 1000000 0.00 D 10519200 I See Footnote Common Stock 2020-01-22 4 J 0 34615 0.00 A 34615 I By APNG I Management Common Stock 2020-01-22 4 J 0 34615 0.00 D 0 I By APNG I Management Common Stock 2020-01-22 4 J 0 11538 0.00 A 11538 D Common Stock 2020-01-22 4 J 0 11538 0.00 A 11538 I By Hudson Capital LLC Common Stock 2020-01-22 4 J 0 11539 0.00 A 11539 I By Alta Bioequities, L.P. Common Stock 2020-01-22 4 J 0 6837 0.00 A 6837 D Represents a pro-rata in-kind distribution of Common Stock of the Issuer by Alta Partners NextGen Fund I L.P. ("APNG I"), without consideration, to its general partner and limited partners. Consists of 2,557,377 shares held of record by APNG I and 7,961,823 shares held of record by Alta Partners VIII, L.P. ("Alta VIII"). The shares directly held by Alta VIII are indirectly held by Alta Partners Management VIII, LLC ("Alta Management VIII"), which is the general partner of Alta VIII. The individual managing directors of Alta Management VIII are Farah Champsi, Guy Nohra and Daniel Janney. The managing directors of Alta Management VIII exercise sole voting and investment control with respect to the shares held by Alta VIII. The individual managing directors of Alta Management VIII disclaim beneficial ownership of all shares held by Alta VIII, except to the extent of their respective pecuniary interests therein. The shares directly held by APNG I are indirectly held by Alta Partners NextGen Fund I Management, LLC ("APNG I Management"), which is the general partner of APNG I. The individual managing directors of APNG I Management are Robert More, Peter Hudson and Daniel Janney. The managing directors of APNG I Management exercise sole voting and investment control with respect to the shares held by APNG I. The individual managing directors of APNG I Management disclaim beneficial ownership of all shares held by APNG I, except to the extent of their respective pecuniary interests therein. Represents a pro-rata in-kind distribution of Common Stock of the Issuer by APNG I Management, without consideration, to its members. Represents the acquisition of the shares of Common Stock of the Issuer by Robert J. More in connection with the pro-rata distribution described in footnote (5) herein. Represents the acquisition of the shares of Common Stock of the Issuer by Hudson Capital, LLC, a limited liability company of which Peter A. Hudson is the managing member, in connection with the pro-rata distribution described in footnote (5) herein. Mr. Hudson disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein. Represents the acquisition of the shares of Common Stock of the Issuer by Alta Bioequities, L.P. in connection with the pro-rata distribution described in footnote (5) herein. Alta Bioequities Management, LLC is the general partner of Alta Bioequities, L.P. and may be deemed to have sole voting and investment power over the shares beneficially owned by Alta Bioequities, L.P. Daniel Janney is the Managing Director of Alta Bioequities Management, LLC. The reporting person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein. Represents the acquisition of the shares of Common Stock of the Issuer by Guy P. Nohra in connection with the pro-rata distribution described in footnote (1) herein. /s/ Daniel Janney, Managing Director, Alta Partners NextGen Fund I Management, LLC 2020-01-24 /s/ Daniel Janney, Managing Director, Alta Partners Management VIII, LLC 2020-01-24 /s/ Daniel Janney, Managing Director, Alta Partners NextGen Fund I, L.P. 2020-01-24 /s/ Farah Champsi 2020-01-24 /s/ Peter A. Hudson 2020-01-24 /s/ Robert J. More 2020-01-24 /s/ Guy P. Nohra 2020-01-24 /s/ Daniel Janney, Managing Director, Alta Partners VIII, L.P. 2020-01-24 /s/ Daniel Janney 2020-01-24