Company: SNY
Filing Date: 2025-10-27
Form Type: 424B5
Source: 0001193125-25-250786
Chunk: 18

Company: Sanofi
Filing Date: 2025-10-27
Form: 424B5
Chunk 18
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 • |     | 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-15

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 LIBOR. The volatility of SOFR has reflected the underlying volatility of the overnight U.S. Treasury repurchase agreement market. The Federal Reserve Bank of New York has at times conducted operations in the
overnight U.S. Treasury repurchase agreement market in order to help maintain the federal funds rate within a target range. There can be no assurance that the Federal Reserve Bank of New York will or will not continue to conduct such operations in
the future, and the duration and extent of any such operations is inherently uncertain. The effect of any such operations, or of the cessation of such operations to the extent they are commenced, is uncertain and could be materially adverse to
holders of the floating rate notes. In addition, although changes in Compounded SOFR generally are not expected to be as volatile as changes in daily levels of SOFR, the return on and value of the floating rate notes may fluctuate more than floating
rate securities that are linked to less volatile rates.

The amount of interest payable on the