Company: SION
Filing Date: 2025-08-11
Form Type: 10-Q
Source: 0002036042-25-000047
Chunk: 459

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-08-11
Form: 10-Q
Item: Part I, Item 2
Chunk 459
---
 our product candidates. Typically, external expenses are recognized based on an evaluation of the progress to completion of specific tasks using information provided to us by our service providers as of each reporting date. Advance payments that we make for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses, which are expensed as the related goods are delivered or the services are performed, or when it is no longer expected that the goods will be delivered, or the services rendered. Significant judgments and estimates are made in determining the accrued, or prepaid expense balances at the end of any reporting period.

External costs represent a significant portion of our research and development expenses, which we track on a program-by-program basis following the nomination of a product candidate. Our internal research and development expenses consist primarily of personnel-related expenses, including stock- based compensation expenses and allocated expenses. We do not track our internal research and development expenses on a program-by-program basis as they either relate to early-stage research expenses, such as lab supplies or our personnel expenses, consulting fees or other costs that are deployed across multiple programs.

Product candidates in later stages of development generally have higher development costs than those in earlier stages resulting from larger and more complex clinical trials, manufacturing scale-up and an increase in research and development headcount to oversee these activities. As a result, management expects that our research and development expenses will increase substantially over the next several years as we potentially advance our product candidates into later-stage development efforts.

Our future development costs may vary significantly based on a variety of factors, including:

•the timing, complexity and progress of preclinical and clinical development activities;

•the number and scope of preclinical and clinical programs we decide to pursue;

•the extent to which we in-license or acquire other product candidates and technologies to further develop our pipeline;

•the successful initiation and completion of clinical trials with safety, tolerability and efficacy profiles that are satisfactory to domestic and foreign regulatory authorities;

•receipt of marketing approvals, if any, from applicable regulatory authorities;

•the development of commercial-scale manufacturing and distribution processes for our current and any future product candidates;

•our ability to obtain, maintain and protect patent, trade secret protection and regulatory exclusivity for our product candidates, both in the U.S. and internationally;

•our ability to successfully recruit and retain additional employees;

•the timing and amount of milestones, royalties or other payments we must make to our licensing partners; and

•the commercialization of our product candidates, if and when approved.

18

A change in the