Company: SNY
Filing Date: 2025-10-29
Form Type: 424B5
Source: 0001193125-25-255563
Chunk: 34

Company: Sanofi
Filing Date: 2025-10-29
Form: 424B5
Chunk 34
---
 the maturity or redemption date, as applicable, of the Floating Rate Notes to, but excluding, the maturity date or redemption
date, as applicable. If the maturity date of the Floating Rate Notes or date of redemption or repayment falls on a day that is not a business day, the payment of interest and principal will be made on the next succeeding business day, and no
interest on such payment will accrue during the period from and after such original maturity date or date of redemption or repayment. Payments postponed to the next business day described above, as applicable, will be treated under the Indenture as
if they were made on the original due date, except for the continued accrual of interest and commencement of the following interest period as described above. Postponements of this kind, as applicable, will not result in a default under the Notes or
the Indenture.

The interest rate for any interest period will be Compounded SOFR, as determined on the applicable date that is the second
U.S. Government Securities Business Day (as defined below) immediately preceding the related Floating Rate Interest Payment Date or, in the case of redemption of the Floating Rate Notes, the date of redemption, as applicable (the “Interest
Determination Date”), plus a margin of 0.460%, in the case of the 2027 Floating Rate Notes, and 0.540%, in the case of the 2028 Floating Rate Notes.

S-24

All payments of interest on the floating rate notes due on any Floating Rate Interest Payment Date will be made to the persons in whose names the floating rate notes are registered at the close of business on January 19, April 18, July 19 and October 19, as applicable (which are the regular record dates), immediately preceding the related Floating Rate Interest Payment Date. However, interest that we pay on the maturity or redemption date, as applicable, will be payable to the person to whom the principal will be payable. Interest on the Floating Rate Notes will be calculated on the basis of a 360-dayyear and the actual number of calendar days in such interest period. Deutsche Bank Trust Company Americas, or its successor appointed by us, will act as calculation agent. We may change the calculation agent with respect to the Floating Rate Notes at any time without notice to the holders of the Floating Rate Notes. The interest rate and amount of interest to be paid on the Floating Rate Notes for each interest period will be determined by the calculation agent. All determinations made by the calculation agent, in