SRRK

SEC source: 0001104659-18-037317 · a4.xml · derivative · entry 10

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 293,813 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · derivative · entry 9

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 719,559 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · derivative · entry 8

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 551,807 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · derivative · entry 7

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 634,579 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · derivative · entry 6

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 437,859 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · nonDerivative · entry 5

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 2,637,617

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · nonDerivative · entry 4

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 2,343,804

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · nonDerivative · entry 3

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 1,624,245

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · nonDerivative · entry 2

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 1,072,438

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037317 · a4.xml · nonDerivative · entry 1

ARCH Venture Fund VIII, L.P. · CIK 0001605598 · 10% owner

ARCH Venture Partners VIII, LLC · CIK 0001616165 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

BYBEE CLINTON · CIK 0001219043 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

ARCH Venture Partners VIII, L.P. · CIK 0001616176 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund VIII, L.P.

Disclosed balance after: 437,859

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis at the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. or ARCH Partners VIII, which may be deemed to beneficially own the shares held by ARCH Fund VIII. The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC or ARCH VIII LLC, which may be deemed to beneficially own the shares held by ARCH Fund VIII. ARCH Partners VIII and ARCH VIII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VIII LLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001104659-18-037316 · a4.xml · derivative · entry 1

CHICKO RHONDA M. · CIK 0001740376 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,208

Underlying: Common Stock · 15,208 shares

Expires 2028-05-23

F1 · derivative.exercise_date: This option was granted on May 23, 2018 and following the closing of the Issuer's initial public offering on May 29, 2018, the vesting period for the stock option commenced and the stock option shall vest and become exercisable in 16 equal quarterly installments with the first quarterly amount to vest on August 29, 2018.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 26

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 16,542 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 25

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 283,090 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 24

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 40,514 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 23

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 693,294 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 22

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 15,233 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 21

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 260,670 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 20

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 28,028 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 19

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 479,634 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 18

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 28,851 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 17

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 493,705 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 16

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 19,340 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · derivative · entry 15

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 330,948 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.exercise_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F1 · derivative.expiration_date: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 14

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 156,395

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 13

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,676,311

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 12

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 148,508

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 11

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,541,341

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 10

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 131,966

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 9

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,258,251

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 8

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 91,452

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 7

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,564,957

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 6

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 76,219

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 5

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,304,287

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 4

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 48,191

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 3

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 824,653

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 2

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 19,340

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F4 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners Founders' Fund VI, L.P. ("PVPFF VI"). PVM VI is the general partner of PVPFF VI. PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVPFF VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVPFF VI. Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037315 · a4.xml · nonDerivative · entry 1

Nashat Amir · CIK 0001575843 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 330,948

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each share of Preferred Stock automatically converted into Common Stock, for no additional payment or consideration, on a 2.8548-for-1 basis upon the closing of the Issuer's initial public offering on May 29, 2018 and had no expiration date.

F2 · ownership.nature: The reportable securities are owned directly by Polaris Venture Partners VI, L.P. ("PVP VI"). Polaris Venture Management Co. VI, L.L.C. ("PVM VI") is the general partner of PVP VI and PVM VI is managed by its managing members, one of whom is the Reporting Person and a member of the Issuer's Board of Directors (collectively, the "Managing Members"). PVM VI may be deemed to have sole voting and dispositive power with respect to the shares held by PVP VI and each of the Reporting Person and the other Managing Members may be deemed to have shared voting and dispositive power with respect to the shares held by PVP VI.

F3 · ownership.nature: Each of the Reporting Person, PVM VI and the other Managing Members disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the Reporting Person, PVM VI or any of the other Managing Members is a beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

SEC source: 0001104659-18-037314 · a4.xml · derivative · entry 1

Ezickson Elan · CIK 0001486429 · COO & Head of Corp.Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,757

Underlying: Common Stock · 8,757 shares

Expires 2028-02-20

F1 · derivative.exercise_date: This option vested in full upon the closing of the Issuer's initial public offering on May 29, 2018. The performance criteria for the entire option grant of 8,757 shares was met, resulting in the full vesting of the option.