X0206 3 2020-06-11 0 0001733294 Generation Bio Co. GBIO 0001340097 Invus Public Equities, L.P. 750 LEXINGTON AVENUE 30TH FLOOR NEW YORK NY 10022 0 0 1 0 0001460839 Minne Pascal 8 CLOS DU BOCAGE, B-1332 GENVAL, BELGIUM CITIZENSHIP: BELGIUM C9 BELGIUM 0 0 1 0 0001218180 Artal International S.C.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001522131 Artal International Management S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001053906 Artal Group S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001283968 Westend S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001460840 Stichting Administratiekantoor Westend CLAUDE DEBUSSYLAAN, 46 1082 MD AMSTERDAM THE NETHERLANDS P7 NETHERLANDS 0 0 1 0 0001766952 Artal Treasury Ltd P.O. BOX 165 SUITE 4, BOROUGH HOUSE, RUE DU PRE ST. PETER PORT GY1 3JJ 0 0 1 0 0001340096 Invus Public Equities Advisors, LLC 750 LEXINGTON AVENUE, 30TH FLOOR NEW YORK NY 10022 0 0 1 0 Series B Preferred Stock Common Stock 1406664 I See Footnotes Series C Preferred Stock Common Stock 607527 I See Footnotes The Series B Preferred Stock automatically convert into the number of shares of Common Stock as shown in Column 3 without payment of further consideration at the holder's election or upon closing of the initial public offering of the Issuer's common stock. The shares have no expiration date. The shares are held directly by Invus Public Equities, L.P. The general partner of Invus Public Equities, L.P. is Invus Public Equities Advisors, LLC. Artal Treasury Ltd is the managing member of Invus Public Equities Advisors, LLC. Artal Treasury Ltd is a wholly owned subsidiary of the Geneva branch of Artal International S.C.A. The managing partner of Artal International S.C.A. is Artal International Management S.A., both of which are wholly owned subsidiaries of Artal Group S.A., which is a wholly owned subsidiary of Westend S.A., which is a wholly owned subsidiary of Stichting Administratiekantoor Westend (the "Stichting"). (Continued from Footnote 2) Mr. Pascal Minne is the sole member of the board of the Stichting. Each of the Reporting Persons, other than Invus Public Equities L.P., disclaims beneficial ownership of the securities held by the other Reporting Persons, except to the extent of such reporting person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Exchange Act, each of the reporting persons (other than to the extent it directly holds securities reported herein) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 of the Exchange Act or for any other purpose. The Series C Preferred Stock automatically convert into the number of shares of Common Stock as shown in Column 3 without payment of further consideration at the holder's election or upon closing of the initial public offering of the Issuer's common stock. The shares have no expiration date. /s/ Invus Public Equities, L.P., By: Invus Public Equities Advisors, LLC, its General Partner, By: Raymond Debbane, President, /s/ Raymond Debbane 2020-06-11 /s/ Invus Public Equities Advisors, LLC, By: Raymond Debbane, President, /s/ Raymond Debbane 2020-06-11 /s/ Artal Treasury Ltd, By: Keith Le Poidevin, Director, /s/ Keith Le Poidevin 2020-06-11 /s/ Artal International S.C.A., By: Artal International Management S.A., its Managing Partner, By: Anne Goffard, Managing Director, /s/ Anne Goffard 2020-06-11 /s/ Artal International Management S.A., By: Anne Goffard, Managing Director, /s/ Anne Goffard 2020-06-11 /s/ Artal Group S.A., By: Anne Goffard, Authorized Person, /s/ Anne Goffard 2020-06-11 /s/ Westend S.A., By: Pascal Minne, Director, /s/ Pascal Minne 2020-06-11 /s/ Stichting Administratiekantoor Westend, By: Pascal Minne, Sole Member of the Board, /s/ Pascal Minne 2020-06-11 /s/ Pascal Minne 2020-06-11