IRON

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 6

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 373,224

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.52 to $94.255 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 5

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 375,017

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.52 to $93.3796 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 4

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 377,022

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.5289 to $92.4325 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (3), (4), (7), (8), (9) and (10).

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 3

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 418,335

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.52 to $94.255 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 421,781

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.52 to $93.3796 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-25-121740 · tm2530644-8_4seq1.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 425,633

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.5289 to $92.4325 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (3), (4), (7), (8), (9) and (10).

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001193125-25-319503 · ownership.xml · derivative · entry 6

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 75,375

Underlying: Common Stock · 40,000 shares

Expires 2031-09-13

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 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

F6 · derivative.exercise_date: The shares underlying this option are fully vested and exercisable as of the date hereof.

SEC source: 0001193125-25-319503 · ownership.xml · nonDerivative · entry 5

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 171,828

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.46 to $94.24, inclusive.

SEC source: 0001193125-25-319503 · ownership.xml · nonDerivative · entry 4

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 188,716

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.46 to $93.44, inclusive.

SEC source: 0001193125-25-319503 · ownership.xml · nonDerivative · entry 3

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 205,072

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.46 to $92.43, inclusive.

SEC source: 0001193125-25-319503 · ownership.xml · nonDerivative · entry 2

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 209,409

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $90.40 to $91.37, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) through (5) to this Form 4.

SEC source: 0001193125-25-319503 · ownership.xml · nonDerivative · entry 1

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 211,828

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 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2025.

SEC source: 0001193125-25-280766 · ownership.xml · derivative · entry 6

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 7,941

Underlying: Common Stock · 30,000 shares

Expires 2030-08-10

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 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

F6 · derivative.exercise_date: The shares underlying this option are fully vested and exercisable as of the date hereof.

SEC source: 0001193125-25-280766 · ownership.xml · nonDerivative · entry 5

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 40,555

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.69 to $86.28, inclusive.

SEC source: 0001193125-25-280766 · ownership.xml · nonDerivative · entry 4

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 48,595

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.69 to $85.68, inclusive.

SEC source: 0001193125-25-280766 · ownership.xml · nonDerivative · entry 3

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 57,955

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $83.63 to $84.62, inclusive.

SEC source: 0001193125-25-280766 · ownership.xml · nonDerivative · entry 2

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 62,540

F1 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $82.63 to $83.61, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) through (5) to this Form 4.

SEC source: 0001193125-25-280766 · ownership.xml · nonDerivative · entry 1

Yu Jonathan Yen-Wen · CIK 0001951849 · Chief Operating Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 70,555

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 · kind: The transactions reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on July 22, 2025.

SEC source: 0001193125-25-249944 · ownership.xml · nonDerivative · entry 1

AI DMI LLC · CIK 0001890993 · 10% owner

Access Industries Holdings LLC · CIK 0001391297 · 10% owner

ACCESS INDUSTRIES MANAGEMENT, LLC · CIK 0001508226 · 10% owner

Blavatnik Len · CIK 0001326628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,814,379

F1 · kind: On October 22, 2025, AI DMI LLC ("AI DMI") sold 744,047 shares of common stock of Disc Medicine, Inc., par value $0.0001 per share, pursuant to an underwritten secondary offering.

F1 · shares: On October 22, 2025, AI DMI LLC ("AI DMI") sold 744,047 shares of common stock of Disc Medicine, Inc., par value $0.0001 per share, pursuant to an underwritten secondary offering.

F2 · ownership.direct: The securities reported are held directly by AI DMI and may be deemed to be beneficially owned by Access Industries Holdings LLC ("AIH"), Access Industries Management, LLC ("AIM") and Len Blavatnik because Len Blavatnik controls AIM and holds a majority of the outstanding voting interests in AIH, AIM controls AIH, and AIH indirectly controls all of the outstanding voting interests in AI DMI LLC. Each of the reporting persons (other than AI DMI) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this form shall not be construed as an admission that any such reporting person is the beneficial owner of any of the securities reported on this form.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 17

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 385,549

F11 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.37 to $92.15 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 16

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 442,036

F11 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.37 to $92.15 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 15

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 385,999

F10 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $90.25 to $91.24 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 14

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 442,486

F10 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $90.25 to $91.24 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 13

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 396,094

F9 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.25 to $90.23 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 12

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 452,580

F9 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.25 to $90.23 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 11

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 398,345

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $88.17 to $89.04 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 10

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 454,831

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $88.17 to $89.04 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 9

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 411,359

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.12 to $88.03 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 8

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 467,845

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.12 to $88.03 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 7

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 416,424

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.91 to $86.90 inclusive.

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 6

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 472,911

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $85.91 to $86.90 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 5

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 419,424

F5 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 4

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 475,911

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 3

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 477,036

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $76.52 to $77.30 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 478,461

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $77.75 to $77.77 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000006 · form4-10172025_081039.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 481,079

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $76.75 to $77.60 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (3), (4), (6), (7), (8), (9), (10) and (11).

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 7

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 500,621

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $72.0474 to $72.6152 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 6

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 513,888

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.03 to $72.0233 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 5

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 526,577

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.0293 to $71.028 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 4

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 551,977

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.0173 to $69.9882 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 3

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 564,363

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.01 to $69.00 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 572,582

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.00 to $69.08 inclusive.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001591747-25-000004 · form4-10092025_081000.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 579,243

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.00 to $68.12 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (3), (4), (5), (6), (7) and (8).

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001193125-25-207557 · ownership.xml · derivative · entry 1

GEMAYEL GEORGES · CIK 0001256088 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,000

Underlying: Common Stock · 1,000 shares

Expires 2035-09-15

F1 · derivative.exercise_date: The shares underlying this option vest upon the first to occur of (i) the date of the Company's 2026 annual meeting of its stockholders, or (ii) the one-year anniversary of the grant date, subject to the Reporting Person's continued service on such vesting date.

SEC source: 0001586788-25-000004 · ownership.xml · derivative · entry 2

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 198,420

Underlying: Common Stock · 10,000 shares

Expires 2030-03-10

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_date: The shares underlying this option are fully vested and exercisable as of the date hereof.

SEC source: 0001586788-25-000004 · ownership.xml · nonDerivative · entry 1

Quisel John D · CIK 0001586788 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 171,828

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.

SEC source: 0001415889-25-023049 · form4-08262025_100853.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 590,621

F1 · kind: Shares were sold pursuant to a Rule 10b5-1 trading plan dated January 31, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.95 to $61.05 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F3 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-25-022124 · form4-08152025_110842.xml · nonDerivative · entry 2

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 592,908

F1 · kind: Shares were sold pursuant to a Rule 10b5-1 trading plan dated January 31, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.95 to $61.11 inclusive.

F3 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-25-022124 · form4-08152025_110842.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 600,120

F1 · kind: Shares were sold pursuant to a Rule 10b5-1 trading plan dated January 31, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.95 to $61.615 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (4).

F3 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-25-021281 · form4-08072025_050804.xml · nonDerivative · entry 1

Bitterman Kevin · CIK 0001591747 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 625,082

F1 · kind: Shares were sold pursuant to a Rule 10b5-1 trading plan dated January 31, 2025.

F2 · ownership.nature: These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.