Company: SION
Filing Date: 2025-08-11
Form Type: 10-Q
Source: 0002036042-25-000047
Chunk: 478

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-08-11
Form: 10-Q
Item: Part I, Item 2
Chunk 478
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 as an add-on to the standard of care. Developing combination treatments increases complexity and risk, including risks of drug-drug interactions, unforeseen side effects or failures in our clinical trials that could delay or prevent their regulatory approval or limit the commercial profile of an approved label.

The current treatment paradigm in CF for all patients with the F508del mutation is based on a combination of drug therapies. We intend to evaluate SION-719 in combination with the current standard of care in a Phase 2a proof-of-concept trial in CF patients, which we expect to initiate in the second half of 2025 after completion of a drug-drug interaction trial. We also intend to evaluate SION-451 in dual combinations with our two most advanced complementary modulator candidates, galicaftor (SION-2222) and SION-109. The use of our product candidates in combination with each other and with an approved product may subject us to risks that we would not face if our product candidates were being developed to be administered as a monotherapy.

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For example, either the combination of our product candidates with each other, or an NBD1 stabilizer with the standard of care, may result in adverse side effects or toxicities that the product candidates or other therapy do not produce when used alone. In addition, the product candidates may interact with each other, or with the approved product, in undesirable ways that could negatively impact the efficacy of our product candidates, any components of the approved product, or the combination as a whole. Testing product candidates in combination with each other and with an approved therapy may increase the risk of significant adverse effects or failed clinical trials. The timing, outcome and cost of developing products to be used in combination with other therapies is difficult to predict and dependent on a number of factors that are outside our reasonable control.

In addition, to the extent we choose to develop a product candidate for use in combination with an approved therapy, the FDA or comparable foreign regulatory authorities could revoke approval of, or that safety, efficacy, manufacturing or supply issues could arise with, the therapy used in combination with our product candidate. If the therapies we use in combination with our product candidates are replaced as the standard of care, the FDA or comparable foreign regulatory authorities may require us to conduct additional clinical trials, or we may not be able to obtain adequate reimbursement from third-party payors. The occurrence of any of these risks could result in our product candidates, if approved, being removed from the market or being less successful commercially. If the FDA or comparable