ELVN

SEC source: 0000899243-20-008471 · doc4.xml · derivative · entry 2

Alexandria Venture Investments, LLC · CIK 0001722024 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 19,913 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: On March 16, 2020, the Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: On March 16, 2020, the Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: On March 16, 2020, the Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

SEC source: 0000899243-20-008471 · doc4.xml · nonDerivative · entry 1

Alexandria Venture Investments, LLC · CIK 0001722024 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 293,013

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: On March 16, 2020, the Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

SEC source: 0001104659-20-034768 · tm2012989-1_4.xml · derivative · entry 3

RA CAPITAL MANAGEMENT, L.P. · CIK 0001346824 · 10% owner

RA Capital Healthcare Fund LP · CIK 0001315082 · 10% owner

Kolchinsky Peter · CIK 0001384859 · 10% owner

Shah Rajeev M. · CIK 0001619841 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 829,348 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: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.exercise_date: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F1 · derivative.expiration_date: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F2 · derivative.underlying_shares: These securities include 652,033 shares held by RA Capital Healthcare Fund, L.P. (the "Fund"), 62,201 shares held by RA Capital Nexus Fund, L.P. ("Nexus") and 115,114 shares held in a separately managed account (the "Account").

F3 · ownership.nature: RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund, Nexus, and the Account. The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, Dr. Kolchinsky, and Mr. Shah may be deemed indirect beneficial owners of the reported securities for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act").

F4 · ownership.nature: They disclaim beneficial ownership of any of the reported securities for the purpose of determining whether they are subject to Section 16 of the Act, however, in reliance on Rule 16a-1(a)(1)(v) and (vii). To the extent that they might be deemed subject to Section 16, they disclaim beneficial ownership of securities held by the Fund and Nexus for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein, and disclaim any pecuniary interest in securities held in the Account for purposes of Rule 16a-1(a)(2).

F5 · ownership.nature: The filing of this Form 4 shall not be construed as an admission that either the Adviser, the Adviser GP, Dr. Kolchinsky, or Mr. Shah is or was for the purposes of Section 16(a), or otherwise, the beneficial owner of any of the securities held in the Account.

SEC source: 0001104659-20-034768 · tm2012989-1_4.xml · nonDerivative · entry 2

RA CAPITAL MANAGEMENT, L.P. · CIK 0001346824 · 10% owner

RA Capital Healthcare Fund LP · CIK 0001315082 · 10% owner

Kolchinsky Peter · CIK 0001384859 · 10% owner

Shah Rajeev M. · CIK 0001619841 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 1,454,348

F6 · kind: The shares were purchased in the Issuer's initial public offering.

F7 · balance_after: These securities include 1,151,230 shares held by the Fund, 108,083 shares held by the Nexus, and 195,035 shares held by the Account.

F3 · ownership.nature: RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund, Nexus, and the Account. The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, Dr. Kolchinsky, and Mr. Shah may be deemed indirect beneficial owners of the reported securities for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act").

F4 · ownership.nature: They disclaim beneficial ownership of any of the reported securities for the purpose of determining whether they are subject to Section 16 of the Act, however, in reliance on Rule 16a-1(a)(1)(v) and (vii). To the extent that they might be deemed subject to Section 16, they disclaim beneficial ownership of securities held by the Fund and Nexus for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein, and disclaim any pecuniary interest in securities held in the Account for purposes of Rule 16a-1(a)(2).

F5 · ownership.nature: The filing of this Form 4 shall not be construed as an admission that either the Adviser, the Adviser GP, Dr. Kolchinsky, or Mr. Shah is or was for the purposes of Section 16(a), or otherwise, the beneficial owner of any of the securities held in the Account.

SEC source: 0001104659-20-034768 · tm2012989-1_4.xml · nonDerivative · entry 1

RA CAPITAL MANAGEMENT, L.P. · CIK 0001346824 · 10% owner

RA Capital Healthcare Fund LP · CIK 0001315082 · 10% owner

Kolchinsky Peter · CIK 0001384859 · 10% owner

Shah Rajeev M. · CIK 0001619841 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 829,348

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: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.

F2 · balance_after: These securities include 652,033 shares held by RA Capital Healthcare Fund, L.P. (the "Fund"), 62,201 shares held by RA Capital Nexus Fund, L.P. ("Nexus") and 115,114 shares held in a separately managed account (the "Account").

F3 · ownership.nature: RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund, Nexus, and the Account. The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, Dr. Kolchinsky, and Mr. Shah may be deemed indirect beneficial owners of the reported securities for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act").

F4 · ownership.nature: They disclaim beneficial ownership of any of the reported securities for the purpose of determining whether they are subject to Section 16 of the Act, however, in reliance on Rule 16a-1(a)(1)(v) and (vii). To the extent that they might be deemed subject to Section 16, they disclaim beneficial ownership of securities held by the Fund and Nexus for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein, and disclaim any pecuniary interest in securities held in the Account for purposes of Rule 16a-1(a)(2).

F5 · ownership.nature: The filing of this Form 4 shall not be construed as an admission that either the Adviser, the Adviser GP, Dr. Kolchinsky, or Mr. Shah is or was for the purposes of Section 16(a), or otherwise, the beneficial owner of any of the securities held in the Account.

SEC source: 0000078003-20-000023 · primary_doc.xml · derivative · entry 7

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Pfizer Ventures (US) LLC

Disclosed balance after: 0

Underlying: Common Stock · 300,752 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.

F3 · derivative.exercise_price: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series B Preferred Stock had no expiration date.

F3 · derivative.exercise_date: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series B Preferred Stock had no expiration date.

F3 · derivative.expiration_date: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series B Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · derivative · entry 6

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Pfizer Ventures (US) LLC

Disclosed balance after: 0

Underlying: Common Stock · 868,467 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.

F2 · derivative.exercise_price: On March 16, 2020, each share of Series A Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series A Preferred Stock had no expiration date.

F2 · derivative.exercise_date: On March 16, 2020, each share of Series A Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series A Preferred Stock had no expiration date.

F2 · derivative.expiration_date: On March 16, 2020, each share of Series A Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series A Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · derivative · entry 5

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 76,003 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: On March 16, 2020, each share of Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series Seed Preferred Stock had no expiration date.

F1 · derivative.exercise_date: On March 16, 2020, each share of Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series Seed Preferred Stock had no expiration date.

F1 · derivative.expiration_date: On March 16, 2020, each share of Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series Seed Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · nonDerivative · entry 4

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Pfizer Ventures (US) LLC

Disclosed balance after: 1,481,719

F5 · price: Pfizer Ventures (US) LLC purchased 312,500 additional shares of common stock in the Issuer's initial public offering at the initial public offering price of $16.00 per share.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · nonDerivative · entry 3

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Pfizer Ventures (US) LLC

Disclosed balance after: 1,169,219

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.

F3 · price: On March 16, 2020, the Issuer's Series B Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series B Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series B Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · nonDerivative · entry 2

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Pfizer Ventures (US) LLC

Disclosed balance after: 868,467

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.

F2 · price: On March 16, 2020, each share of Series A Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series A Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000078003-20-000023 · primary_doc.xml · nonDerivative · entry 1

PFIZER INC · CIK 0000078003 · 10% owner

Pfizer Ventures (US) LLC · CIK 0001776087 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 76,003

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: On March 16, 2020, each share of Series Seed Preferred Stock converted into Common Stock on a 6.299-for-1 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series Seed Preferred Stock was convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The Series Seed Preferred Stock had no expiration date.

F4 · ownership.direct: Each reporting person disclaims ownership of securities held by each other reporting person, except to the extent of its respective pecuniary interest therein.

SEC source: 0000899243-20-008477 · doc4.xml · nonDerivative · entry 1

ORBIMED ADVISORS LLC · CIK 0001055951 · Director · 10% owner

OrbiMed Capital GP VII LLC · CIK 0001760648 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By OrbiMed Private Investments VII, LP

Disclosed balance after: 937,500

F2 · ownership.nature: These securities are held of record by OrbiMed Private Investments VII, LP, or OPI VII. OrbiMed Capital GP VII LLC, or GP VII, is general partner of OPI VII, and OrbiMed Advisors LLC, or Advisors, is the managing member of GP VII. By virtue of such relationships, GP VII and Advisors may be deemed to have voting and investment power with respect to the shares held by OPI VII. Both GP VII and Advisors may be deemed to directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of the shares held by OPI VII. Advisors exercises investment and voting power through a management committee comprised of Carl L. Gordon, Jonathan T. Silverstein, and Sven H. Borho, each of whom disclaims beneficial ownership of the shares of OPI VII.

F3 · ownership.nature: Each of GP VII, Advisors and OPI VII disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. The Reporting Persons have designated a representative, David P. Bonita ("Bonita"), a member of Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-20-008495 · doc4.xml · nonDerivative · entry 1

Bonita David P · CIK 0001572451 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By OrbiMed Private Investments VII, LP

Disclosed balance after: 937,500

F2 · ownership.nature: The securities are held by OrbiMed Private Investments VII, LP, or OPI VII. OrbiMed Capital GP VII LLC, or GP VII, is general partner of OPI VII, and OrbiMed Advisors LLC, or Advisors, is the managing member of GP VII. The Reporting Person is a member of Advisors. By virtue of such relationships, GP VII and Advisors may be deemed to have voting and investment power with respect to the shares held by OPI VII. Both GP VII and Advisors may be deemed to directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of the shares held by OPI VII. Advisors exercises investment and voting power through a management committee comprised of Carl L. Gordon, Jonathan T. Silverstein, and Sven H. Borho, each of whom disclaims beneficial ownership of the shares held by OPI VII.

F3 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purpose of Section 16 of the Exchange Act, or for any other purpose.