REGN

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 14

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,770,713

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F17 · price: Purchase prices range from $482.91 to $483.90 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 13

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,765,697

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F16 · price: Purchase prices range from $481.89 to $482.59 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 12

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,763,997

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F15 · price: Purchase prices range from $480.82 to $481.80 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 11

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,746,241

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F14 · price: Purchase prices range from $479.80 to $480.77 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 10

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,732,603

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F13 · price: Purchase prices range from $478.79 to $479.70 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 9

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,724,330

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F12 · price: Purchase prices range from $477.79 to $478.76 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 8

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,721,004

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F11 · price: Purchase prices range from $476.79 to $477.78 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 7

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,710,075

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F10 · price: Purchase prices range from $475.55 to $476.43 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 6

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,704,972

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F9 · price: Purchase prices range from $474.40 to $475.21 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 7

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,099

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 6

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,199

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 5

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,367

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 4

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,467

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 5

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,702,339

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F8 · price: Purchase prices range from $479.91 to $480.86 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 4

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,689,302

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F7 · price: Purchase prices range from $478.89 to $479.87 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 3

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,665,430

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F6 · price: Purchase prices range from $477.81 to $478.80 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 2

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,653,244

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F5 · price: Purchase prices range from $476.78 to $477.75 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001140361-17-033310 · form4.xml · nonDerivative · entry 1

Sanofi · CIK 0001121404 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See note

Disclosed balance after: 23,643,644

F1 · shares: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2 · shares: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F1 · price: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F3 · price: Purchase prices range from $475.51 to $476.50 per share, inclusive.

F4 · ownership.nature: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventisub LLC ("Aventis"), formerly Aventis Pharmaceuticals Inc., an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 21,008,607 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 17

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 329,543

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 16

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 329,649

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 15

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 330,049

F15 · price: Represents volume-weighted average price of sales of 4,661 shares of Company stock on August 22, 2017 at prices ranging from $481.00 to $481.95. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 14

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 334,710

F14 · price: Represents volume-weighted average price of sales of 5,250 shares of Company stock on August 22, 2017 at prices ranging from $480.06 to $480.97. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 13

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 339,960

F13 · price: Represents volume-weighted average price of sales of 600 shares of Company stock on August 22, 2017 at prices ranging from $479.00 to $479.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 12

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 340,560

F12 · price: Represents volume-weighted average price of sales of 1,600 shares of Company stock on August 22, 2017 at prices ranging from $478.10 to $478.93. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 11

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 342,160

F11 · price: Represents volume-weighted average price of sales of 3,473 shares of Company stock on August 22, 2017 at prices ranging from $477.00 to $477.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 10

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 345,633

F10 · price: Represents volume-weighted average price of sales of 5,744 shares of Company stock on August 22, 2017 at prices ranging from $476.01 to $476.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 9

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 351,377

F9 · price: Represents volume-weighted average price of sales of 5,610 shares of Company stock on August 22, 2017 at prices ranging from $475.00 to $475.94. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 8

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 356,987

F8 · price: Represents volume-weighted average price of sales of 2,400 shares of Company stock on August 22, 2017 at prices ranging from $474.00 to $474.91. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 7

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 359,387

F7 · price: Represents volume-weighted average price of sales of 200 shares of Company stock on August 22, 2017 at prices ranging from $473.55 to $473.75. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 6

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 359,587

F6 · price: Represents volume-weighted average price of sales of 900 shares of Company stock on August 22, 2017 at prices ranging from $472.38 to $472.97. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 5

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 360,487

F5 · price: Represents volume-weighted average price of sales of 600 shares of Company stock on August 22, 2017 at prices ranging from $471.16 to $471.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 4

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 361,087

F4 · price: Represents volume-weighted average price of sales of 400 shares of Company stock on August 22, 2017 at prices ranging from $470.50 to $470.84. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 22, 2017 at each separate price.

SEC source: 0001708138-17-000019 · edgardoc.xml · derivative · entry 9

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 62,000

Underlying: Common Stock · 2,000 shares

Expires 2023-09-09

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: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

F2 · derivative.exercise_date: The stock option award vests in four equal annual installments, commencing one year after the date of grant.

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 3

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,567

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 2

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,955

F1 · kind: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000019 · edgardoc.xml · nonDerivative · entry 1

Landry Robert E · CIK 0001585160 · SVP Finance & CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,099

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: Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 3

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 361,487

F3 · price: Represents volume-weighted average price of sales of 200 shares of Company stock on August 21, 2017 at prices ranging from $472.08 to $472.24 Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 21, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 2

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 361,687

F2 · price: Represents volume-weighted average price of sales of 1,951 shares of Company stock on August 21, 2017 at prices ranging from $471.00 to $471.86. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 21, 2017 at each separate price.

SEC source: 0001708138-17-000017 · edgardoc.xml · nonDerivative · entry 1

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 363,638

F1 · price: Represents volume-weighted average price of sales of 22,118 shares of Company stock on August 21, 2017 at prices ranging from $470.00 to $470.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 21, 2017 at each separate price.

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 7

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 385,756

F3 · price: Represents volume-weighted average price of sales of 2,900 shares of Company stock on August 18, 2017 at prices ranging from $470.00 to $470.54. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 18, 2017 at each separate price.

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 6

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 388,656

F2 · price: Represents volume-weighted average price of sales of 1,305 shares of Company stock on August 17, 2017 at prices ranging from $470.00 to $470.03. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 17, 2017 at each separate price.

SEC source: 0001104659-18-007629 · a5.xml · nonDerivative · entry 4

YANCOPOULOS GEORGE · CIK 0001226690 · Director · President and CSO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 423,609

SEC source: 0001708138-17-000015 · edgardoc.xml · derivative · entry 12

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 153,969

Underlying: Common Stock · 153,969 shares

Expires 2017-12-17

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.

F5 · derivative.exercise_date: The stock option award (combined incentive stock option and non-qualified stock option) vests in four equal annual installments, commencing one year after the date of grant.

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 5

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 389,961

F1 · price: Represents volume-weighted average price of sales of 10,986 shares of Company stock on August 16, 2017 at prices ranging from $470.00 to $470.95. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on August 16, 2017 at each separate price.

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 4

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 400,947

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 3

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 476,353

SEC source: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 2

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 483,512

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: 0001708138-17-000015 · edgardoc.xml · nonDerivative · entry 1

VAGELOS P ROY · CIK 0001013064 · Director · Chairman of the Board

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 329,543

SEC source: 0001708138-17-000013 · edgardoc.xml · derivative · entry 3

Terifay Robert J · CIK 0001391382 · EVP Commercial

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,921 shares

Expires 2021-12-16

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 stock option award (combined incentive stock option and non-qualified stock option) vests in four equal annual installments, commencing one year after the date of grant.

SEC source: 0001708138-17-000013 · edgardoc.xml · nonDerivative · entry 1

Terifay Robert J · CIK 0001391382 · EVP Commercial

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,214

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.