Core Viewpoint - Sionna Therapeutics is focused on transforming the treatment of cystic fibrosis (CF) by developing innovative medicines that normalize the function of the CFTR protein [2]. Company Overview - Sionna Therapeutics is a clinical-stage biopharmaceutical company dedicated to revolutionizing CF treatment through novel medicines aimed at restoring CFTR function [2]. - The company aims to deliver differentiated therapies that stabilize the nucleotide binding domain 1 (NBD1) of the CFTR protein, which is believed to be crucial for improving clinical outcomes and quality of life for CF patients [2]. - Sionna is advancing a pipeline of small molecules designed to correct defects caused by the F508del genetic mutation in NBD1 and is also developing complementary CFTR modulators to enhance CFTR function [2]. Investor Engagement - Sionna will participate in investor events, including the Cantor Global Healthcare Conference on September 3, 2025, and the Morgan Stanley 23rd Annual Global Healthcare Conference on September 8, 2025 [4]. - Live webcasts of these presentations will be available on the company's Investor Relations website, with replays accessible after the events [1][3].

Core Viewpoint - Sionna Therapeutics has initiated dosing for SION-451 in combination with SION-2222 and SION-109 in a Phase 1 trial, aiming to transform cystic fibrosis treatment with novel CFTR modulators, with topline data expected in mid-2026 [1][2][3] Company Overview - Sionna Therapeutics is a clinical-stage biopharmaceutical company focused on developing medicines that normalize CFTR protein function, specifically targeting the NBD1 domain to improve clinical outcomes for cystic fibrosis patients [5] - The company aims to deliver differentiated therapies that restore CFTR function to near-normal levels, leveraging over a decade of research on NBD1 and developing small molecules to correct defects caused by the F508del mutation [5] Clinical Trial Details - The Phase 1 trial is randomized, double-blind, and placebo-controlled, assessing the safety, tolerability, and pharmacokinetics of SION-451 in dual combinations with SION-2222 and SION-109 [2] - Topline data from this trial is anticipated in mid-2026, which will guide the selection of a dual combination for a planned Phase 2b trial in cystic fibrosis patients [2] Scientific Rationale - Positive data from previous Phase 1 trials and preclinical studies support the advancement of the dual combination trial, with SION-451 showing good tolerability and exceeding pharmacokinetic concentration targets [4] - The NBD1 domain is critical for CFTR protein stability and function, and no approved therapies currently stabilize this domain directly, highlighting the innovative approach of Sionna's research [3][4]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q _________________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _____ to _____ Commission file number 001-42504 _________________________ SIONNA THERAPEUTICS, INC. (Exact name of ...

Waltham, Mass.,August 11, 2025 (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) by developing novel medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, today reported financial results for the quarter ended June 30, 2025, and provided a business update. "We are pleased with the progress we've made this past qu ...

Financial Data and Key Metrics Changes - The company raised $219 million from its IPO in February 2025, providing significant financial flexibility and a cash runway extending into 2028 [54][55] - The market for cystic fibrosis treatments is currently valued at $11 billion and is projected to grow to $15 billion in the near term [53] Business Line Data and Key Metrics Changes - The company has concluded Phase I trials for both CYON719 and CYON451R2, reporting positive data indicating both compounds were well tolerated and exceeded pharmacokinetic (PK) targets [8][9] - CYON719 will advance into Phase IIa as an add-on to standard care, while CYON451 will be used in a dual combination study [11][12] Market Data and Key Metrics Changes - The company aims to drive incremental clinical benefits above the standard of care, specifically targeting a 10 millimole improvement in sweat chloride levels compared to Trikafta [27][40] - The company is focused on stabilizing the NBD1 region of the CFTR protein, which is critical for correcting cystic fibrosis [18][22] Company Strategy and Development Direction - The company's mission is to transform the standard of care in cystic fibrosis through differentiated NBD1 stabilizers [5][6] - The strategy includes a dual combination approach with NPD-one as the anchor, aiming to achieve fully normal CFTR function for more patients [7][21] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the potential of NPD-one to deliver clinically meaningful benefits, emphasizing the need for further data to guide future decisions [44][52] - The company is optimistic about the upcoming Phase IIa data and its implications for both the add-on and dual combination strategies [42][45] Other Important Information - The company has prioritized two complementary mechanisms, Cyon2222 and Cyon109, for future studies based on their favorable profiles [46][48] - The company plans to conduct a drug-drug interaction (DDI) study to ensure that the addition of CYON719 does not affect the components of Trikafta [34][36] Q&A Session Summary Question: Can you provide an overview of Ciona's story and strategy? - Ciona was formed as a spinout from Sanofi in late 2019, with a mission to transform cystic fibrosis care through innovative therapies [3][4] Question: What are the key milestones for the company in the next 12-18 months? - Key milestones include the initiation of Phase IIa for CYON719 and a healthy volunteer study for CYON451, both expected to yield data by mid-2026 [14][16] Question: How does the company plan to ensure the efficacy of its treatments? - The company aims for a 10 millimole improvement in sweat chloride levels, which has been shown to correlate with meaningful improvements in FEV1 [27][40] Question: What is the rationale behind the dual combination strategy? - The dual combination strategy is expected to provide a differentiated treatment option that could lead to fully normal CFTR function, addressing the limitations of current therapies [21][52] Question: How does the company view the commercial opportunity in the cystic fibrosis market? - The company believes that its dual combination approach could become the new standard of care, with significant commercial potential given the size of the market [52][53]

Core Insights - Sionna Therapeutics is focused on developing novel medicines to normalize the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, aiming to revolutionize the treatment paradigm for cystic fibrosis (CF) [1][4] Company Overview - Sionna Therapeutics is a clinical-stage biopharmaceutical company dedicated to creating therapies that restore CFTR function, particularly targeting the nucleotide-binding domain 1 (NBD1) [4] - The company has a pipeline of small molecules designed to correct defects caused by the F508del genetic mutation, which is prevalent in CF patients [4] Research and Development - Sionna has developed NBD1 stabilizers, SION-719 and SION-451, which have shown the ability to increase the stability of isolated ΔF508-NBD1 by 16°C, surpassing wild-type NBD1 levels [5] - Preclinical data indicate that SION-719 and SION-451 can correct F508del-CFTR maturation to wild-type levels when combined with other modulators, SION-2222 and SION-109 [5] - The company plans to advance SION-719 into a Phase 2a proof-of-concept trial and SION-451 into a Phase 1 trial, both expected to start in the second half of 2025 [3] Conference Presentation - Sionna presented preclinical data at the 48th European Cystic Fibrosis Conference, showcasing the effectiveness of dual combinations of NBD1 stabilizers with proprietary modulators [1][3]

Sionna Therapeutics Overview - Sionna's approach to stabilizing NBD1 has the potential to revolutionize CF treatment, addressing the unmet need for >66% of patients who lack normal CFTR function[7] - The CFTR modulator market is currently >$11 billion and is projected to reach $15 billion by 2029[7] - Sionna has a robust clinical-stage pipeline of NBD1 stabilizers and complementary modulators, offering multiple paths to transform CF patient care[7] Phase 1 Clinical Trial Results - Both NBD1 stabilizers, SION-719 and SION-451, exceeded desired PK targets and were generally well-tolerated in Phase 1 trials[13] - SION-719 is advancing to a Phase 2a proof-of-concept trial as an add-on to standard of care (SOC), based on its high potency at low doses[13] - SION-451 is advancing as an anchor in proprietary dual combinations, based on higher exposure achieved[13] Clinical Development Strategy - A Phase 2a proof-of-concept trial for SION-719 in CF patients is planned for the second half of 2025[14] - A Phase 1 healthy volunteer dual combination trial for SION-451 is also planned for the second half of 2025[14] - Sionna's cash runway extends into 2028, supporting the execution of its clinical development plans[14, 61] Market Opportunity - Approximately 106,000 patients worldwide have CF, with ~90% having at least one F508del-CFTR mutation[55] - >66% of patients on SOC do not have normal CFTR function, highlighting the significant unmet need[55, 59]

Summary of Ciona Therapeutics Conference Call Company Overview - **Company**: Ciona Therapeutics - **Focus**: Development of novel therapies for cystic fibrosis (CF) targeting CFTR function Key Industry Insights - **Cystic Fibrosis Market**: - Current market size exceeds $11 billion and is expected to grow - Approximately two-thirds of CF patients do not achieve normal CFTR function despite existing treatments [6][34] - The most common mutation, F508L, affects about 90% of CF patients [9] Core Points and Arguments - **Phase I Data**: - Positive results for compounds CYON-seven 19 and CYON-four 51, indicating potential for significant clinical benefits [4][11] - Both compounds exceeded pharmacokinetic targets and demonstrated favorable tolerability profiles [11][20] - **Targeting NDD1**: - NDD1 is identified as a key target for normalizing CFTR function, which has been historically considered undruggable [6][7] - Ciona aims to provide a unique and clinically meaningful option for CF patients by stabilizing NDD1 [5][10] - **Clinical Strategy**: - Plans to advance CYON-seven 19 into a Phase 2a trial as an add-on to standard care (Trikafta) [12][28] - CYON-four 51 will be evaluated in a dual combination trial with complementary modulators [12][32] - Both trials are expected to initiate in the second half of 2025, with data anticipated by mid-2026 [14][28] - **Clinical Assays**: - The CF human bronchial epithelial (CFHBE) assay is critical for predicting clinical outcomes and guiding development [21][22] - Data from the CFHBE assay indicates that both compounds are positioned to deliver meaningful clinical benefits [23][27] Additional Important Information - **Safety and Tolerability**: - No serious adverse events reported in Phase I trials for both compounds, supporting their advancement to further studies [20][26] - Mild to moderate treatment-emergent adverse events were observed, with no dose-limiting toxicities [20][26] - **Market Opportunity**: - Ciona is focused on the unmet needs of CF patients, particularly those with the F508del mutation, and aims to improve CFTR function significantly [34][36] - The company is well-funded through 2028, allowing for the execution of its clinical goals [36] - **Strategic Optionality**: - The decision to pursue both add-on and dual combination strategies provides flexibility in development paths [59][60] - The company emphasizes a data-driven approach to determine the best path forward based on clinical outcomes [60] Conclusion - Ciona Therapeutics is positioned to potentially transform the treatment landscape for cystic fibrosis with its innovative approach targeting CFTR function through NDD1 stabilization. The promising Phase I data and strategic clinical plans highlight the company's commitment to addressing significant unmet needs in the CF patient population.

SION-719 and SION-451 were generally well tolerated and achieved desired pharmacokinetic targets that reinforce their potential as either an add-on to standard of care or in a Sionna dual combination Positive Phase 1 Results for SION-719 and SION-451 The Phase 1 randomized, double-blind, placebo-controlled clinical trials evaluated the safety, tolerability, and PK profiles of single ascending doses (SAD) and multiple ascending doses (MAD) of SION-719 and SION-451 in healthy volunteers. The effect of food on ...

Core Insights - Sionna Therapeutics is focused on developing novel medicines to treat cystic fibrosis (CF) by normalizing the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein [1][3] - The company will present preclinical data on its NBD1 stabilizers, SION-451 and SION-719, in combination with CFTR modulators, galicaftor (SION-2222) and SION-109, at the European Cystic Fibrosis Conference [1][2] Company Overview - Sionna Therapeutics is a clinical-stage biopharmaceutical company aiming to revolutionize CF treatment through innovative medicines that stabilize CFTR's nucleotide-binding domain 1 (NBD1) [3] - The company is developing a pipeline of small molecules targeting the F508del genetic mutation and complementary CFTR modulators to enhance CFTR function [3] Presentation Details - The oral presentation titled "Stabilizers of CFTR NBD1 synergize with galicaftor (SION-2222) or SION-109 to enable full correction of ΔF508-CFTR" will take place on June 6, 2025 [2] - The presentation will be available on Sionna's website under the "Scientific Presentations" section [2]