Company: SNY
Filing Date: 2025-10-27
Form Type: 424B5
Source: 0001193125-25-250786
Chunk: 87

Company: Sanofi
Filing Date: 2025-10-27
Form: 424B5
Chunk 87
---
 that are disadvantageous to you, in connection with a merger, consolidation or sale or lease of assets that is permitted under the indenture. However, we may not take any of these actions unless all the following conditions are met:

| • |     | Where we merge out of existence or sell or lease substantially all of our assets, the other entity must be duly 
 organized and validly existing under the laws of the relevant jurisdiction.                                     |

| • |     | If we merge out of existence or sell or lease our assets substantially as an entirety, the other entity must                                                                                                                           
 assume, through a supplemental indenture, our obligations under the applicable indenture and the debt securities, including our obligation to pay additional amounts described below under “— Payment of Additional Amounts.” In the   
 event the jurisdiction of incorporation of the successor is not the Republic of France, such successor will also agree to be bound to the obligations described below under “— Payment of Additional Amounts” but shall substitute the 
 successor’s jurisdiction of incorporation for the Republic of France.                                                                                                                                                                  |

| • |     | If we merge out of existence or sell or lease our assets substantially as an entirety, we must provide to the                                                                                          
 trustee a certificate signed by a duly authorized officer and an opinion of legal counsel stating that the conditions set forth in the indenture have been complied with. (Sections 801, 802 and 1007) |

Modification and Waiver There are three types of changes we can make to the indenture and the debt securities. Changes Requiring Your Approval.First, there are changes that cannot be made to your debt securities without your specific approval, for example, by calling a meeting of holders and seeking a 100% quorum and unanimous consent, or, more likely, by obtaining written consents from each holder including pursuant to an exchange offer and/or a consent solicitation. We must obtain your approval in order to:

| • |     | change the stated maturity of the principal or interest on a debt security; |

| • |     | reduce the principal of, premium, if any, amount or rate of interest payable on a debt security; |

| • |     | reduce the amount of principal payable upon acceleration of the maturity of a debt security following a default; |

| • |     | change the place or currency of payment on a debt security; |

| • |     | impair your right to sue for payment; |

| • |     | reduce the percentage of holders of a series of debt securities whose consent is needed