Kania Edwin

Row 3 · 2019-05-13 · Conversion · Acquired 751,691 · Balance 1,430,301

F3: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.0001 per share ("Common Stock") on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 4 · 2019-05-13 · Conversion · Acquired 2,255,074 · Balance 2,255,074

F3: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.0001 per share ("Common Stock") on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 5 · 2019-05-13 · Conversion · Acquired 209,933 · Balance 1,640,234

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 6 · 2019-05-13 · Conversion · Acquired 503,840 · Balance 2,758,914

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 7 · 2019-05-13 · Conversion · Acquired 545,826 · Balance 545,826

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 8 · 2019-05-13 · Conversion · Acquired 120,795 · Balance 1,761,029

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 9 · 2019-05-13 · Conversion · Acquired 335,457 · Balance 3,094,371

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 10 · 2019-05-13 · Conversion · Acquired 82,324 · Balance 628,150

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 11 · 2019-05-13 · Conversion · Acquired 194,409 · Balance 3,288,780

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 12 · 2019-05-13 · Conversion · Acquired 48,602 · Balance 676,752

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 13 · 2019-05-13 · Conversion · Acquired 486,023 · Balance 486,023

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F9: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. serves as sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 14 · 2019-05-13 · Purchase · Acquired 500,000 · Balance 986,023

F9: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. serves as sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 1 · Balance 678,610

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 2 · Balance 2,035,830

F2: Shares held by Flagship VentureLabs IV, LLC ("VentureLabs IV"). Flagship Ventures Fund IV, L.P. ("Flagship Fund IV") is a member of VentureLabs IV and also serves as its manager. Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP") is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by VentureLabs IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 15 · 2019-05-13 · Conversion · Disposed 1,384,615 · Balance 0

F3: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.0001 per share ("Common Stock") on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 16 · 2019-05-13 · Conversion · Disposed 4,153,847 · Balance 0

F3: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.0001 per share ("Common Stock") on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 17 · 2019-05-13 · Conversion · Disposed 386,697 · Balance 0

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 18 · 2019-05-13 · Conversion · Disposed 928,074 · Balance 0

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 19 · 2019-05-13 · Conversion · Disposed 1,005,413 · Balance 0

F5: Each share of Series B Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 20 · 2019-05-13 · Conversion · Disposed 222,506 · Balance 0

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship Fund 2007"). Flagship Ventures 2007 General Partner LLC ("Fund 2007 GP") is the general partner of Flagship Fund 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Fund 2007 GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 21 · 2019-05-13 · Conversion · Disposed 617,914 · Balance 0

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 22 · 2019-05-13 · Conversion · Disposed 151,643 · Balance 0

F7: Each share of Series C Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 23 · 2019-05-13 · Conversion · Disposed 358,102 · Balance 0

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F4: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 24 · 2019-05-13 · Conversion · Disposed 89,525 · Balance 0

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F6: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship Fund IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV-Rx. Each of the reporting persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 25 · 2019-05-13 · Conversion · Disposed 895,255 · Balance 0

F8: Each share of Series E Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-1.842 basis upon the closing of the Issuer's initial public offering.

F9: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. serves as sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 1 · 2017-05-16 · Sale · Disposed 266,795 · Balance 560,067

F1: Held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 LLC") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. Flagship 2007 LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Mr. Kania disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

Row 2 · Balance 26,528

F2: Includes 26,528 shares that was previously received by Mr. Kania in a pro rata distribution by Flagship 2007 LLC that was exempt from reporting pursuant to Rule 16a-13.

Row 1 · 2018-05-11 · Conversion · Acquired 14,622,143 · Balance 17,952,153

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 2 · 2018-05-11 · Purchase · Acquired 281,250 · Balance 18,233,403

F6: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 3 · 2018-05-11 · Conversion · Disposed 12,536,945 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 4 · 2018-05-11 · Conversion · Disposed 10,102,055 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 5 · 2018-05-11 · Conversion · Disposed 5,416,667 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 6 · 2018-05-11 · Conversion · Disposed 8,333,000 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 7 · 2018-05-11 · Conversion · Disposed 18,611,110 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 8 · 2018-05-11 · Conversion · Disposed 4,643,963 · Balance 0

F7: 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.

F1: 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,

F2: [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.

F3: 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.

F4: 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").

F5: 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.

Row 4 · 2019-03-04 · Conversion · Acquired 665,908 · Balance 665,908

F4: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.001 ("Common Stock"), on a one-for-two basis upon the closing of the Issuer's initial public offering.

F5: Shares held by Flagship Ventures Fund IV, L.P. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 5 · 2019-03-04 · Conversion · Acquired 173,586 · Balance 216,451

F6: Each share of Series A-1 Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-two basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 GP") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. While Mr. Kania is retired from Flagship Pioneering, Inc., he continue to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 6 · 2019-03-04 · Conversion · Acquired 281,203 · Balance 947,111

F6: Each share of Series A-1 Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-two basis upon the closing of the Issuer's initial public offering.

F5: Shares held by Flagship Ventures Fund IV, L.P. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 1 · Balance 42,865

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 GP") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. While Mr. Kania is retired from Flagship Pioneering, Inc., he continue to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 2 · Balance 42,865

F2: Shares held by Flagship VentureLabs IV, LLC ("VentureLabs IV"). Flagship Ventures Fund IV, L.P. ("Flagship Fund IV") is a member of VentureLabs IV and also serves as its manager. Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP") is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by VentureLabs IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein

Row 3 · Balance 1,649,999

F3: Shares held by Cadena LLC ("Cadena"). Noubar B. Afeyan, Ph.D. is the sole manager of Cadena, and may be deemed to possess sole voting and investment power with respect to all shares held by Cadena. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 7 · 2019-03-04 · Conversion · Disposed 1,331,816 · Balance 0

F4: Each share of Series A Preferred Stock converted into shares of the Issuer's common stock, par value $0.001 ("Common Stock"), on a one-for-two basis upon the closing of the Issuer's initial public offering.

F5: Shares held by Flagship Ventures Fund IV, L.P. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 8 · 2019-03-04 · Conversion · Disposed 347,173 · Balance 0

F6: Each share of Series A-1 Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-two basis upon the closing of the Issuer's initial public offering.

F1: Shares held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 GP") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. While Mr. Kania is retired from Flagship Pioneering, Inc., he continue to serve as a manager of Flagship 2007 GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 9 · 2019-03-04 · Conversion · Disposed 562,407 · Balance 0

F6: Each share of Series A-1 Preferred Stock converted into shares of the Issuer's Common Stock on a one-for-two basis upon the closing of the Issuer's initial public offering.

F5: Shares held by Flagship Ventures Fund IV, L.P. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. While Mr. Kania is retired from Flagship Pioneering, Inc., he continues to serve as a manager of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 1 · 2020-01-10 · Sale · Disposed 357,375 · Balance 141,472

F1: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.00 to $20.745, 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.

Row 2 · 2020-01-14 · Sale · Disposed 117,625 · Balance 23,847

F2: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.90 to $20.155, 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.

Row 2 · 2018-07-20 · Conversion · Acquired 15,323,593 · Balance 15,323,593

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F3: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. 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. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 3 · 2018-07-20 · Conversion · Acquired 3,830,402 · Balance 3,830,402

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F4: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. 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 IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 4 · 2018-07-20 · Conversion · Acquired 5,000,000 · Balance 5,000,000

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 5 · 2018-07-20 · Conversion · Acquired 5,000,000 · Balance 5,000,000

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 6 · 2018-07-20 · Conversion · Acquired 593,948 · Balance 5,593,948

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 7 · 2018-07-20 · Conversion · Acquired 593,948 · Balance 5,593,948

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 8 · 2018-07-20 · Conversion · Acquired 1,781,843 · Balance 1,781,843

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 9 · 2018-07-20 · Conversion · Acquired 195,466 · Balance 5,789,414

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 10 · 2018-07-20 · Conversion · Acquired 195,466 · Balance 5,789,414

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 11 · 2018-07-20 · Conversion · Acquired 781,860 · Balance 2,563,703

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 1 · Balance 5,000,000

F1: Shares held by Flagship VentureLabs IV LLC ("VentureLabs IV"). Flagship Ventures Fund IV, L.P. ("Flagship Fund IV") is a member of VentureLabs IV and also serves as its manager. Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP") is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by VentureLabs IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 12 · 2018-07-20 · Conversion · Disposed 15,323,593 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F3: Shares held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. 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. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 13 · 2018-07-20 · Conversion · Disposed 3,830,402 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F4: Shares held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship Fund IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. 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 IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 14 · 2018-07-20 · Conversion · Disposed 5,000,000 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 15 · 2018-07-20 · Conversion · Disposed 5,000,000 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 16 · 2018-07-20 · Conversion · Disposed 593,948 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 17 · 2018-07-20 · Conversion · Disposed 593,948 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 18 · 2018-07-20 · Conversion · Disposed 1,781,843 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 19 · 2018-07-20 · Conversion · Disposed 195,466 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F5: Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Fund V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 20 · 2018-07-20 · Conversion · Disposed 195,466 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F6: Shares held by Flagship V VentureLabs Rx Fund, L.P. ("VentureLabs Rx V"). Flagship Fund V GP is the general partner of VentureLabs Rx V. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund V GP and may be deemed to possess sole voting and investment power with respect to all shares held by VentureLabs Rx V. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 21 · 2018-07-20 · Conversion · Disposed 781,860 · Balance 0

F2: The preferred stock is convertible into the Issuer's common stock on a one-for-one basis at the holder's election and has no expiration date. The preferred stock automatically convert into common stock upon the closing of the Issuer's initial public offering held on July 20, 2018.

F7: Shares held by Flagship Ventures Opportunities Fund I, L.P. ("Flagship Opportunities Fund I"). Flagship Ventures Opportunities Fund I General Partner LLC ("Flagship Opportunities GP") is the general partner of Flagship Opportunities I. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Opportunities GP and may be deemed to possess sole voting and investment power with respect to all shares held by Flagship Opportunities I. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

Row 1 · 2017-08-17 · Other · Disposed 1,295,997 · Balance 2,378,663

F1: On August 17, 2017, Flagship Ventures Fund IV, L.P. ("Flagship IV") and Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx") distributed to its limited partners and sole general partner, Flagship Ventures Fund IV General Partner, LLC ("Flagship IV LLC"), pro rata and without consideration, 1,295,997 shares and 306,222 shares, respectively, of the Issuer's common stock. Flagship IV LLC, in turn, distributed to its members, pro rata and without consideration, the 54,283 shares and 10 shares it received from Flagship IV and Flagship IV-Rx, respectively. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr., each a manager of Flagship IV LLC, each received 24,527 shares through Flagship IV LLC's distribution.

F2: Held by Flagship IV. Flagship IV LLC is the general partner of Flagship IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV. Each of the filing persons other than Flagship IV disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 2 · 2017-08-17 · Other · Disposed 306,222 · Balance 612,442

F1: On August 17, 2017, Flagship Ventures Fund IV, L.P. ("Flagship IV") and Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx") distributed to its limited partners and sole general partner, Flagship Ventures Fund IV General Partner, LLC ("Flagship IV LLC"), pro rata and without consideration, 1,295,997 shares and 306,222 shares, respectively, of the Issuer's common stock. Flagship IV LLC, in turn, distributed to its members, pro rata and without consideration, the 54,283 shares and 10 shares it received from Flagship IV and Flagship IV-Rx, respectively. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr., each a manager of Flagship IV LLC, each received 24,527 shares through Flagship IV LLC's distribution.

F3: Held by Flagship IV-Rx. Flagship IV LLC is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons other than Flagship IV-Rx disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 3 · 2017-08-17 · Other · Disposed 54,293 · Balance 0

F1: On August 17, 2017, Flagship Ventures Fund IV, L.P. ("Flagship IV") and Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx") distributed to its limited partners and sole general partner, Flagship Ventures Fund IV General Partner, LLC ("Flagship IV LLC"), pro rata and without consideration, 1,295,997 shares and 306,222 shares, respectively, of the Issuer's common stock. Flagship IV LLC, in turn, distributed to its members, pro rata and without consideration, the 54,283 shares and 10 shares it received from Flagship IV and Flagship IV-Rx, respectively. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr., each a manager of Flagship IV LLC, each received 24,527 shares through Flagship IV LLC's distribution.

F4: Held by Flagship IV LLC. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV LLC. Each of the filing persons other than Flagship IV LLC disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 4 · Balance 213,332

F5: Held by Flagship VentureLabs IV, LLC ("VentureLabs IV"). Flagship IV is the manager of VentureLabs IV. Flagship IV LLC is the general partner of Flagship IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV, Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by VentureLabs IV. Each of the filing persons other than VentureLabs IV disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 5 · Balance 24,527

F1: On August 17, 2017, Flagship Ventures Fund IV, L.P. ("Flagship IV") and Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx") distributed to its limited partners and sole general partner, Flagship Ventures Fund IV General Partner, LLC ("Flagship IV LLC"), pro rata and without consideration, 1,295,997 shares and 306,222 shares, respectively, of the Issuer's common stock. Flagship IV LLC, in turn, distributed to its members, pro rata and without consideration, the 54,283 shares and 10 shares it received from Flagship IV and Flagship IV-Rx, respectively. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr., each a manager of Flagship IV LLC, each received 24,527 shares through Flagship IV LLC's distribution.

F6: Held by Noubar B. Afeyan, Ph.D. Each of the filing persons other than Noubar B. Afeyan, Ph.D. disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 6 · Balance 24,527

F1: On August 17, 2017, Flagship Ventures Fund IV, L.P. ("Flagship IV") and Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx") distributed to its limited partners and sole general partner, Flagship Ventures Fund IV General Partner, LLC ("Flagship IV LLC"), pro rata and without consideration, 1,295,997 shares and 306,222 shares, respectively, of the Issuer's common stock. Flagship IV LLC, in turn, distributed to its members, pro rata and without consideration, the 54,283 shares and 10 shares it received from Flagship IV and Flagship IV-Rx, respectively. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr., each a manager of Flagship IV LLC, each received 24,527 shares through Flagship IV LLC's distribution.

F7: Held by Edwin M. Kania, Jr. Each of the filing persons other than Edwin M. Kania, Jr. disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein.

Row 1 · 2026-05-20 · Grant · Acquired 2,922 · Balance 263,732

F1: Consists of 2,922 restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock.

Row 2 · Balance 46,142