Company: SION
Filing Date: 2025-02-03
Form Type: S-1/A
Source: 0001193125-25-018825
Chunk: 193

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-03
Form: S-1/A
Chunk 193
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 to us under the Sanofi License Agreement under certain circumstances, provided that any such sublicense must be consistent with the terms of the Sanofi License Agreement. If we receive sublicense income from any such sublicense, we are
required to pay Sanofi a low double digit percentage of such sublicense income.

We have also granted Sanofi an exclusive option to purchase, at a
defined price, any priority review voucher (“PRV”) granted to us as a result of the development of the licensed compounds or products. In the event that Sanofi does not exercise its option with respect to any PRV, we may (x) use the
PRV, in which case we must pay Sanofi a high seven-digit amount or (y) sell the PRV to a third party, in which case we must share a sub-teen double-digit percentage of the sale consideration with Sanofi.

We have the right, but not the obligation, to prepare, file, prosecute and maintain the licensed patents and product trademarks at our own cost. We
have the first right to enforce and defend any licensed patents, with Sanofi having back-up enforcement and defense rights. We also have the sole right to enforce and defend any product trademarks at our sole
cost and expense.

We have the right to terminate the Sanofi License Agreement for convenience, subject to a
90-day notice period. Sanofi has customary termination rights under the Sanofi License Agreement, including for our material breach, payment default, bankruptcy or challenge of the validity of any patent

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right, subject to specified notice and cure periods. Unless earlier terminated, the Sanofi License Agreement will expire in each country upon the expiration of the
last-to-expire royalty term in such country and, with respect to the Sanofi License Agreement in its entirety, upon the expiration of the royalty term for the last
licensed product for which there has been a first commercial sale. Upon expiration of the Sanofi License Agreement, the license granted to us will become non-exclusive, royalty-free, fully paid-up and perpetual.

CFF Payment Agreement

On December 20, 2019, we entered into a payment agreement (the “CFF Payment Agreement”) with CFF, pursuant to which we agreed to provide
CFF with compensation in exchange for the grant of, or forbearance from exercising, certain of CFF’s rights existing under the Research, Development and Commercialization Agreement, dated October 1, 2011, by and between CFF (through an
assignment by Cystic Fibrosis