X0306 4 2018-05-11 0 0001694665 Evelo Biosciences, Inc. EVLO 0001508051 Flagship Ventures Fund IV General Partner LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001642578 Flagship VentureLabs IV, LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001503559 Flagship Ventures Fund IV, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001590973 Flagship Ventures Fund IV-Rx, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 Common Stock 2018-05-11 4 C 0 14622143 0.00 A 17952153 I See footnotes Common Stock 2018-05-11 4 P 0 281250 16.00 A 18233403 I See footnotes Series A Preferred Stock 2018-05-11 4 C 0 12536945 0.00 D Common Stock 3073533 0 I See footnotes Series A-1 Preferred Stock 2018-05-11 4 C 0 10102055 0.00 D Common Stock 2476600 0 I See footnotes Series A-2 Preferred Stock 2018-05-11 4 C 0 5416667 0.00 D Common Stock 1327939 0 I See footnotes Series A-3 Preferred Stock 2018-05-11 4 C 0 8333000 0.00 D Common Stock 2042902 0 I See footnotes Series B Preferred Stock 2018-05-11 4 C 0 18611110 0.00 D Common Stock 4562664 0 I See footnotes Series C Preferred Stock 2018-05-11 4 C 0 4643963 0.00 D Common Stock 1138505 0 I See footnotes Following the transactions reported herein, Flagship VentureLabs IV LLC ("VentureLabs IV") holds 684,372 shares of common stock, Flagship VentureLabs V LLC ("VentureLabs V") holds 2,645,637 shares of common stock, Flagship Ventures Fund IV L.P. ("Flagship Fund IV") holds 1,836,836 shares of common stock, Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx" and, together with VentureLabs IV and Flagship Fund IV, the "Flagship Fund IV Funds") holds 448,911 shares of common stock, Flagship Ventures Fund V, L.P. ("Flagship Fund V") holds 4,201,284 shares of common stock, Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V") holds 1,609,871 shares of common stock, Nutritional Health Side Fund, L.P. ("Nutritional Health Side Fund") holds 795,950 shares of common stock, [Continued] Nutritional Health Disruptive Innovation Fund, L.P. ("Nutritional Innovation Fund" and, together with VentureLabs V, Flagship Fund V, VentureLabs Rx V and Nutritional Health Side Fund, the "Flagship Fund V Funds") holds 3,598,177 shares of common stock, and Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I" and, together with the Flagship Fund IV Funds and Flagship Fund V Funds, the "Flagship Funds") holds 2,412,365 shares of common stock. Flagship Fund IV is a member of VentureLabs IV and also serves as its manager. Flagship Fund V is a member of VentureLabs V and also serves as its manager. The general partner of each of Flagship Fund IV and Flagship Fund IV-Rx is Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP"). The general partner of Flagship Fund V, VentureLabs Rx-V, Nutritional Innovation Fund and Nutritional Health Side Fund is Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP"). The general partner of Flagship Opportunities Fund I is Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP," and together with Flagship Fund IV GP and Flagship Fund V GP, the "Flagship General Partners"). Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV Funds. Dr. Afeyan also serves as the managing member of the Flagship Fund V GP and Flagship Opportunities Fund GP and may be deemed to possess sole voting and investment control over the shares held by the Flagship Fund V Funds and Flagship Opportunities Fund I. Each of the Flagship General Partners, Dr. Afeyan and Mr. Kania disclaims beneficial ownership of any shares beneficially owned by the Flagship Funds except to the extent of its or his pecuniary interest therein. Includes 35,156, 105,469, and 140,625 shares purchased by Nutritional Health Side Fund, Nutritional Innovation Fund, and Flagship Opportunities I, respectively, in connection with the Issuer's initial public offering. Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into the Issuer's common stock on a 0.2452-for-one basis. Due to the limitations of the electronic filing system each of Flagship Ventures Fund V General Partner LLC, Flagship VentureLabs V LLC, Flagship Ventures Fund V, L.P., Flagship V VentureLabs Rx Fund, L.P., Nutritional Health Disruptive Innovation Fund, L.P., Nutritional Health Side Fund, L.P., Flagship Ventures Opportunities Fund I, L.P., Flagship Ventures Opportunities Fund I General Partner LLC, Noubar B. Afeyan and Edwin M. Kania, Jr. are filing a separate Form 4. Flagship Ventures Fund IV General Partner LLC, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Title: Manager 2018-05-15 Flagship VentureLabs IV LLC, By: Flagship Ventures Fund IV, L.P., its manager, By: Flagship Ventures Fund IV General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Title: Manager 2018-05-15 Flagship Ventures Fund IV, L.P., By: Flagship Ventures Fund IV General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Title: Manager 2018-05-15 Flagship Ventures Fund IV-Rx, L.P., By: Flagship Ventures Fund IV General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Title: Manager 2018-05-15