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Sionna Therapeutics (Nasdaq: SION) posts Q1 loss with cash runway into 2028

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(Moderate)
Filing Sentiment
(Neutral)
Form Type
8-K

Rhea-AI Filing Summary

Sionna Therapeutics, Inc. reported first quarter 2026 results and a business update focused on its cystic fibrosis pipeline. The company completed enrollment in its PreciSION CF Phase 2a proof‑of‑concept trial of NBD1 stabilizer SION-719 as an add-on to standard of care, with topline data expected in summer 2026. An ongoing Phase 1 trial of NBD1 stabilizer SION-451 in dual combinations with SION-2222 and SION-109 is also on track for topline data in the summer.

Research and development expenses were $19.0 million and general and administrative expenses were $10.6 million for the quarter, leading to a net loss of $26.8 million, or $0.60 per share. Sionna ended March 31, 2026 with $289.9 million in cash, cash equivalents and marketable securities, which it expects to fund operations into 2028.

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Insights

Sionna advances CF trials, posts larger Q1 loss but holds cash runway into 2028.

Sionna Therapeutics highlighted progress in two clinical programs for cystic fibrosis. Enrollment is complete in the PreciSION CF Phase 2a proof-of-concept trial of SION-719, and a Phase 1 dual-combination trial of SION-451 with complementary CFTR modulators is ongoing, with both readouts anticipated in summer 2026.

Operating expenses increased as the pipeline advanced, with research and development at $19.0 million and general and administrative at $10.6 million, driving a Q1 2026 net loss of $26.8 million, or $0.60 per share. The company held $289.9 million in cash, cash equivalents and marketable securities as of March 31, 2026, and expects this to fund operations into 2028, supporting upcoming trial data and further development work.

Item 2.02 Results of Operations and Financial Condition Financial
Disclosure of earnings results, typically an earnings press release or preliminary financials.
Item 9.01 Financial Statements and Exhibits Exhibits
Financial statements, pro forma financial information, and exhibit attachments filed with this report.
Research and development expenses $19.0 million Quarter ended March 31, 2026
General and administrative expenses $10.6 million Quarter ended March 31, 2026
Net loss $26.8 million Quarter ended March 31, 2026
Net loss per share $0.60 Basic and diluted, Q1 2026
Cash, cash equivalents and marketable securities $289.9 million As of March 31, 2026
Cash, cash equivalents and marketable securities $310.3 million As of December 31, 2025
Total operating expenses $29.6 million Quarter ended March 31, 2026
Weighted-average shares outstanding 44,921,984 shares Basic and diluted, Q1 2026
Phase 2a proof-of-concept trial medical
"Enrollment Completed in PreciSION CF Phase 2a proof-of-concept (POC) trial"
NBD1 stabilizers medical
"Safety, tolerability, and pharmacokinetics of novel NBD1 stabilizers SION-719 and SION-451"
CFTR corrector medical
"SION-2222 (galicaftor), a transmembrane domain 1 (TMD1)-directed CFTR corrector"
working capital financial
"Sionna defines working capital as current assets minus current liabilities."
Working capital is the money a business has available to cover its daily expenses, like paying bills and buying supplies. It’s like the cash in your wallet that helps you handle everyday costs; having enough ensures the business can operate smoothly without running into money shortages.
forward-looking statements regulatory
"This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995"
Forward-looking statements are predictions or plans that companies share about what they expect to happen in the future, like estimating sales or profits. They matter because they help investors understand a company's outlook, but since they are based on guesses and assumptions, they can sometimes be wrong.
Regulation FD regulatory
"for complying with its disclosure obligations under Regulation FD."
Regulation FD is a rule that prevents company insiders, like executives, from sharing important information with some people before others get it. It matters because it helps ensure all investors have equal access to key news, making the stock market fairer and reducing chances of insider trading.
Net loss $26.8 million vs. $16.5 million in Q1 2025
R&D expenses $19.0 million vs. $13.7 million in Q1 2025
G&A expenses $10.6 million vs. $6.0 million in Q1 2025
Net loss per share $0.60 vs. $0.62 in Q1 2025
Cash, cash equivalents and marketable securities $289.9 million vs. $310.3 million at December 31, 2025
0002036042FALSE00020360422026-05-122026-05-12

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
__________________________
FORM 8-K
__________________________
CURRENT REPORT
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of Report (date of earliest event reported): May 12, 2026
__________________________
SIONNA THERAPEUTICS, INC.
(Exact name of registrant as specified in its charter)
__________________________
Delaware001-4250484-2801521
(State or other jurisdiction
of incorporation)
(Commission
File Number)
(I.R.S. Employer
Identification No.)
SIONNA THERAPEUTICS, INC.
21 Hickory Drive, Suite 500
Waltham, MA02451
(Address of principal executive offices, including zip code)
617-819-2020
(Registrant’s telephone number, including area code)
Not Applicable
(Former Name or Former Address, if Changed Since Last Report)
__________________________
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Securities registered pursuant to Section 12(b) of the Act:
Title of each classTrading
Symbol(s)
Name of each exchange
on which registered
Common Stock, $0.001 par value per shareSIONThe Nasdaq Global Market
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).
Emerging growth company x
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o



Item 2.02    Results of Operations and Financial Condition.
On May 12, 2026, Sionna Therapeutics, Inc. issued a press release announcing its financial results and business highlights for the three months ended March 31, 2026. The full text of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.
The information set forth under this Item 2.02 and in Exhibit 99.1 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act, except as expressly set forth by specific reference in such filing.
Item 9.01    Financial Statements and Exhibits.
(d) Exhibits
99.1
Press Release of Sionna Therapeutics, Inc. dated May 12, 2026.
104Cover Page Interactive Data File (embedded within the Inline XBRL document).



SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
Sionna Therapeutics, Inc.
Date: May 12, 2026
By:/s/ Jennifer Fitzpatrick
Name:Jennifer Fitzpatrick
Title:Chief Legal Officer


Sionna Therapeutics Reports First Quarter 2026 Financial Results

Enrollment completed in the PreciSION CF Phase 2a proof-of-concept trial evaluating NBD1 stabilizer SION-719 as an add-on to standard of care in participants with cystic fibrosis; topline data on track for the summer of 2026

Ongoing Phase 1 trial evaluating NBD1 stabilizer SION-451 in proprietary dual combinations with SION-2222 and with SION-109 in healthy volunteers is also on track for topline data in the summer of 2026

Maintained strong cash position with approximately $289.9 million in cash and cash equivalents, expected to fund operations into 2028

WALTHAM, Mass., May 12, 2026 (GLOBE NEWSWIRE) – Sionna Therapeutics, Inc. (Nasdaq: SION), a clinical-stage biopharmaceutical company on a mission to revolutionize the current treatment paradigm for cystic fibrosis (CF) today reported financial results for the first quarter ended March 31, 2026, and provided a business update.

“We entered 2026 with strong execution across our programs, highlighted by the recent completion of enrollment in our proof-of-concept Phase 2a trial of SION-719, an important milestone for Sionna,” said Mike Cloonan, President and Chief Executive Officer of Sionna. “With both of our clinical stage NBD1 stabilizer programs on track for topline readouts this summer, we remain focused on advancing these first-in-class product candidates that could expand therapeutic options for people with CF.”

Pipeline Updates

NBD1 Stabilizers

Enrollment Completed in PreciSION CF Phase 2a Proof-of-Concept Trial with SION-719; Topline Data On Track: In April 2026, Sionna announced it had completed enrollment in the PreciSION CF Phase 2a proof-of-concept (POC) trial (NCT07108153) evaluating SION-719 as an add-on to standard of care (SOC) in CF patients. The trial is evaluating the safety, tolerability, and pharmacokinetics (PK) of SION-719 when administered with SOC and assessing change in CFTR function as measured by sweat chloride levels. Topline data from this trial are anticipated in the summer of this year.
Ongoing Phase 1 Dual Combination Trial with SION-451 and Complementary Modulators; Topline Data On Track: The Phase 1 trial (NCT07035990) is evaluating SION-451 in proprietary dual combinations with SION-2222 (galicaftor), a transmembrane domain 1 (TMD1)-directed CFTR corrector, and with SION-109, an intracellular loop 4 (ICL4)-directed CFTR corrector, in healthy volunteers. Topline data from this trial are anticipated in the summer of this year.
Encore Data to be Presented at 49th European Cystic Fibrosis Conference: Encore data previously presented at the 2025 North American Cystic Fibrosis Conference (NACFC) will be featured in an oral and ePoster presentation at the European Cystic Fibrosis Society’s (ECFS) 49th European Cystic Fibrosis Conference, being held June 3-6, 2026, in Lisbon, Portugal.





Details of the presentations are as follows:

Abstract Title: Safety, tolerability, and pharmacokinetics of novel NBD1 stabilizers SION-719 and SION-451 from two Phase 1 first-in-human studies
Abstract number: EPS07.01
Presenting Author: Jason H. Maley, MD, MS, Senior Director, Clinical Development, Sionna Therapeutics
Oral ePoster Session Title: Old and new – exploring the portfolio for CF treatment
Date and Time: Friday, June 5, 2026, 2:00-2:06 p.m. CEST/9:00-9:06 a.m. ET

Abstract Title: Clinical-stage NBD1 stabilizers can increase F508del-CFTR protein half-life to wild-type levels when used alone or in combination with other CFTR modulators
Abstract ID: WS15.3
Presenting Author: Greg Hurlbut, Ph.D., Co-Founder and Senior Vice President, Discovery Research, Sionna Therapeutics
Session Title: Workshop 15: Novel approaches, future therapies
Date and Time: Friday, June 5, 2026, 5:30-5:45 p.m. CEST/11:30-11:45 a.m. ET

Financial Results for the Quarter Ended March 31, 2026

Research and Development Expenses: Research and development expenses were $19.0 million for the first quarter of 2026, compared to $13.7 million for the first quarter of 2025. These increases were mainly driven by development expenses to support the advancement of Sionna’s clinical pipeline and personnel-related costs, including stock-based compensation expenses, to support the Company’s continued growth and operational activities.

General and Administrative Expenses: General and administrative expenses were $10.6 million for the first quarter of 2026, compared to $6.0 million for the first quarter of 2025. These increases were primarily due to personnel-related costs, including stock-based compensation expenses, to support the Company’s continued growth and operational activities.

Net Loss: Net loss was $26.8 million for the first quarter of 2026, compared to a net loss of $16.5 million for the first quarter of 2025. 

Cash and Cash Equivalents: Cash, cash equivalents and marketable securities totaled $289.9 million as of March 31, 2026. Sionna expects its current cash position to fund operations into 2028. 

About Sionna Therapeutics 
Sionna Therapeutics is a clinical-stage biopharmaceutical company on a mission to revolutionize the current treatment paradigm for cystic fibrosis (CF) by developing novel medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Sionna’s goal is to deliver differentiated medicines for people living with CF that can restore their CFTR function to as close to normal as possible by directly stabilizing CFTR’s nucleotide binding domain 1 (NBD1), which Sionna believes is central to potentially unlocking dramatic improvements in clinical outcomes and quality of life for people with CF. Leveraging more than a decade of the co-founders’ research on NBD1, Sionna is advancing a pipeline of small molecules engineered to correct the defects caused by the F508del genetic mutation, which occurs in NBD1. Sionna is also developing a portfolio of complementary CFTR



modulators that are designed to work synergistically with its NBD1 stabilizers to improve CFTR function. For more information about Sionna, visit www.sionnatx.com.

Sionna intends to use its Investor Relations website as a means of disclosing material nonpublic information and for complying with its disclosure obligations under Regulation FD. Accordingly, investors should monitor Sionna’s Investor Relations website, in addition to following Sionna’s press releases, SEC filings, public conference calls, presentations, and webcasts.
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements about Sionna’s beliefs and expectations regarding: its goal of transforming the treatment paradigm for CF and providing clinically meaningful benefit for CF patients; the potential of Sionna’s product candidates to expand therapeutic options for people with CF; the initiation, timing, progress and results of Sionna’s research and development programs, clinical trials and studies, including the timing of topline data from Sionna’s Phase 2a proof-of-concept trial and Phase 1 dual combination trial; the ability of clinical trials to demonstrate safety and efficacy of Sionna’s product candidates; the ability of Sionna’s preclinical studies or earlier clinical trials to predict later clinical trial results; and financial projections and expectations regarding the time period in which Sionna’s capital resources will be sufficient to fund its anticipated operations, including cash runway, use of capital, expenses and other financial results. In some cases, the forward-looking statements can be identified by terms such as “may,” “will,” “should,” “would,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by the forward-looking statements contained in this press release. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties inherent in the development of product candidates, including uncertainties concerning the initiation, timing, progress, and results of Sionna’s ongoing, planned and future clinical trials and studies; the Company’s ability to replicate positive results from earlier preclinical studies or clinical trials in current or future clinical trials; Sionna’s ability to demonstrate that its NBD1 stabilizers, complementary CFTR modulators, and any potential future product candidates are safe and effective for their proposed indications; regulatory developments in the United States and foreign countries; and general economic, industry and market conditions. These risks and uncertainties are described in the section entitled “Risk Factors” in Sionna’s most recent Annual Report on Form 10-K as well as any subsequent filings with the Securities and Exchange Commission. The events and circumstances reflected in the forward-looking statements may not be achieved or occur. In addition, any forward-looking statements represent Sionna’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Sionna explicitly disclaims any obligation to update any forward-looking statements except as required by law. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.
 
Media Contact 
Sarah Spencer
media@sionnatx.com
 
Investor Contact 
Juliet Labadorf 
ir@sionnatx.com 




Three Months Ended
March 31,
2026
2025
Operating expenses:
Research and development
$
18,963 
$
13,668 
General and administrative
10,636 
5,991 
Total operating expenses
29,599 
19,659 
Loss from operations
(29,599)
(19,659)
Other income:
Interest income
2,820 
3,000 
Other income
177 
Total other income
2,820 
3,177 
Net loss
$
(26,779)
$
(16,482)
Net loss per share, basic and diluted
$
(0.60)
$
(0.62)
Weighted-average common shares outstanding, basic and diluted
44,921,984 
26,596,059 





Sionna Therapeutics, Inc.
Selected Consolidated Balance Sheet Data
(In thousands)
(Unaudited)
March 31,
December 31,
2026
2025
Cash, cash equivalents, and marketable securities
$
289,931 
$
310,302 
Working capital1
211,183 
229,707 
Total assets
305,039 
325,953 
Total stockholders’ equity
288,208 
306,833 
1Sionna defines working capital as current assets minus current liabilities.


FAQ

What were Sionna Therapeutics (SION) key financial results for Q1 2026?

Sionna reported a Q1 2026 net loss of $26.8 million, or $0.60 per share. Research and development expenses were $19.0 million and general and administrative expenses were $10.6 million, reflecting increased investment in clinical and corporate activities.

How much cash does Sionna Therapeutics (SION) have and what is its runway?

As of March 31, 2026, Sionna held $289.9 million in cash, cash equivalents and marketable securities. The company expects this cash position to fund its anticipated operations, including ongoing clinical development, into 2028, providing several years of financial runway.

What progress did Sionna Therapeutics (SION) report on its SION-719 CF trial?

Sionna completed enrollment in its PreciSION CF Phase 2a proof-of-concept trial evaluating NBD1 stabilizer SION-719 as an add-on to standard of care. The study assesses safety, tolerability, pharmacokinetics and CFTR function via sweat chloride, with topline data anticipated in summer 2026.

What is Sionna Therapeutics (SION) doing with SION-451 and its dual combinations?

Sionna is running a Phase 1 trial of NBD1 stabilizer SION-451 in dual combinations with CFTR correctors SION-2222 and SION-109 in healthy volunteers. The trial focuses on safety and pharmacology, with topline data also expected in summer 2026.

How did Sionna Therapeutics’ (SION) operating expenses change in Q1 2026?

Total operating expenses reached $29.6 million in Q1 2026, up from $19.7 million a year earlier. Increases were mainly due to higher research and development spending to advance the clinical pipeline and higher personnel-related costs, including stock-based compensation.

What is Sionna Therapeutics’ (SION) strategic focus in cystic fibrosis treatment?

Sionna is focused on developing NBD1 stabilizers and complementary CFTR modulators to normalize CFTR function in people with cystic fibrosis. Its goal is to create differentiated small-molecule therapies targeting the F508del mutation to improve clinical outcomes and quality of life.

Filing Exhibits & Attachments

4 documents