Company: SNY
Filing Date: 2025-10-29
Form Type: 424B5
Source: 0001193125-25-255563
Chunk: 22

Company: Sanofi
Filing Date: 2025-10-29
Form: 424B5
Chunk 22
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 no longer be determined by reference to the SOFR Index, but instead will be determined by reference toa different rate, plus a spread
adjustment, which we refer to as a “Benchmark Replacement,” as further described under “Description of the Notes — Principal, Interest and Maturity — Floating Rate Notes.”

If a particular Benchmark Replacement (as defined herein) or Benchmark Replacement Adjustment (as defined herein) cannot be determined, then
the next-available Benchmark Replacement or Benchmark Replacement Adjustment will apply. These replacement rates and adjustments may be selected, recommended or formulated by(i) the Relevant Governmental Body (as defined herein), such as the ARRC,
(ii) the International Swaps and Derivatives Association (“ISDA”) or (iii) in certain circumstances, we or our designee. In addition, the terms of the floating rate notes expressly authorize us or our designee to make Benchmark
Replacement Conforming Changes (as defined herein) with respect to, among other things, changes to the definition of “interest period,” the timing and frequency of determining rates and making payments of interest, the rounding of
amounts or tenors and other administrative matters. The determination of a Benchmark Replacement, the calculation of the interest rate on the floating rate notes by reference to a Benchmark Replacement (including the

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application of a Benchmark Replacement Adjustment), any implementation of Benchmark Replacement Conforming Changes and any other determinations, decisions or elections that may be made under the
terms of the floating rate notes in connection with a Benchmark Transition Event, could adversely affect the value of the floating rate notes, the return on the floating rate notes and the price at which holders of the floating rate notes can sell
such floating rate notes.

In addition, (i) the composition and characteristics of the Benchmark Replacement will not be the same as
those of Compounded SOFR, the Benchmark Replacement may not be the economic equivalent of Compounded SOFR, there can be no assurance that the Benchmark Replacement will perform in the same way as Compounded SOFR would have at any time and there is
no guarantee that the Benchmark Replacement will be a comparable substitute for Compounded SOFR (each of which means that a Benchmark Transition Event could adversely affect the value of the floating rate notes, the return on the floating rate notes
and the price at which holders of the floating rate notes can sell such floating rate notes), (ii) any failure of the Benchmark Replacement to gain market acceptance could adversely affect the floating rate notes, (iii) the Benchmark
Replacement may have