Company: SNY
Filing Date: 2025-10-29
Form Type: 424B5
Source: 0001193125-25-255563
Chunk: 18

Company: Sanofi
Filing Date: 2025-10-29
Form: 424B5
Chunk 18
---
 any point in time there may or may not be an active trading market for our notes. At any point in time there may or may not be an active trading market for our notes. We have not listed and do not intend to list the notes on any securities exchange or automated quotation system. In addition, underwriters, broker-dealers and agents that participate in the distribution of the notes may make a market in the notes as permitted by applicable laws and regulations but will have no obligation to do so, and any such market-making activities with respect to the notes may be discontinued at any time without notice. If any of the notes are traded after their initial issuance, they may trade at a discount from their initial offering price. Factors that could cause the notes to trade at a discount include, among others:

| • |     | an increase in prevailing interest rates; |

| • |     | a decline in our credit worthiness; |

| • |     | the time remaining to the maturity; |

| • |     | a weakness in the market for similar securities; and |

| • |     | declining general economic conditions. |

The Secured Overnight Financing Rate (“SOFR”) has a limited history. The Federal Reserve Bank of New York started publishing SOFR in April 2018; therefore, it has a limited history. The future performance of SOFR cannot be predicted based on its limited historical performance. Levels of SOFR going forward may bear little or no relation to historical actual or historical indicative data. Prior observed patterns, if any, in the behavior of market variables and their relation to SOFR may change in the future. While some pre-publicationhistorical data have been released by the Federal Reserve Bank of New York, analysis of such data inherently involves assumptions, estimates and approximations. The future performance of SOFR is impossible to predict and therefore no future performance of SOFR may be inferred from any of the historical actual or historical indicative data. Hypothetical or historical performance data are not indicative of, and have no bearing on, the potential performance of SOFR and there can be no assurance that SOFR will be positive. Changes in the levels of SOFR may affect the return on the floating rate notes and the trading price of the floating rate notes. S-14

SOFR may be more volatile than other benchmark or market rates.

Since the initial publication of SOFR, daily changes in the rate have, on occasion, been more volatile than daily changes in other benchmark
or market rates, such as U.S. Dollar LIB