Company: SNY
Filing Date: 2025-10-27
Form Type: 424B5
Source: 0001193125-25-250786
Chunk: 73

Company: Sanofi
Filing Date: 2025-10-27
Form: 424B5
Chunk 73
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 as through the SEC’s Internet site at http://www.sec.gov. The SEC allows us to incorporate by reference the information we file with them, which means that:

| • |     | incorporated documents are considered part of this prospectus; |

| • |     | we can disclose important information to you by referring to those documents; and |

| • |     | information that we file with the SEC in the future and incorporate by reference herein will automatically update 
 and supersede information in this prospectus and information previously incorporated by reference herein.         |

The information that we incorporate by reference is an important part of this prospectus. Each document incorporated by reference is current only as of the date of such document, and the incorporation by reference of such documents shall not create any implication that there has been no change in our affairs since the date thereof or that the information contained therein is current as of any time subsequent to its date. Any statement contained in such incorporated documents shall be deemed to be modified or superseded for the purpose of this prospectus to the extent that a subsequent statement contained in a supplement to this prospectus or in another document we incorporate by reference at a later date modifies or supersedes that statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate herein by reference:

| • |     | our 2023 Form                                                           
 20-F (File No. 001-31368), filed with the SEC on February 23, 2024, and |

| • |     | any document filed in the future with the SEC under Sections 13(a) and 13(c) or 15(d) of the Exchange Act after                                                                                                   
 the date of this prospectus and until this offering is completed. Any report on Form 6-K that we furnish to the SEC on or after the date of this prospectus (or portions thereof) is incorporated by reference in 
 this prospectus only to the extent that the report expressly states that we incorporate it (or such portions) by reference in this prospectus and that it is not subsequently superseded.                         |

The consolidated financial statements contained in the 2023 Form 20-Fhave been prepared in accordance with International Financial Reporting Standards (IFRS) as issued by the International Accounting Standards Board (IASB) and with IFRS as endorsed by the European Union, as of December 31, 2023. You may also request a copy of documents