Summary of Sionna Therapeutics FY Conference Call Company Overview - **Company**: Sionna Therapeutics (NasdaqGM:SION) - **Industry**: Cystic Fibrosis (CF) Treatment - **Founded**: Late 2019, as a spinout from Sanofi - **Mission**: To revolutionize CF treatment using first-in-class NBD1 stabilizers Key Points and Arguments Unmet Need in Cystic Fibrosis - Despite advancements, a significant unmet need remains in CF treatment, particularly in achieving normal CFTR protein function - Only one-third of patients on standard care reach normal CFTR function, indicating a large opportunity for improvement [4][26] Market Opportunity - The CF market is currently valued at $12 billion and is projected to exceed $15 billion by 2030 [4] - Sionna aims to disrupt this market with novel therapies targeting NBD1, which has been historically considered an undruggable target [5][9] NBD1 Target - NBD1 is crucial for correcting CFTR protein function, and Sionna's approach is to stabilize NBD1, which no approved modulators currently do [5][8] - The company has multiple clinical assets targeting NBD1, with promising preclinical data suggesting potential for significant efficacy improvements [9][10] Pipeline Development - **Lead Compounds**: SION-719 and SION-451, both NBD1 stabilizers, have shown positive Phase 1 data and are advancing to Phase 2A studies [10][12] - SION-719 is in a Phase 2A proof-of-concept study called the Precision CF Study, with expected data by mid-2026 [11][19] - SION-451 is being tested in a dual combination study with complementary mechanisms, also expected to yield data in mid-2026 [20][21] Clinical Strategy - The Precision CF Study aims for a clinically meaningful improvement of at least 10 millimoles in sweat chloride, which correlates with a 3% improvement in FEV1 [22][24] - The study design is efficient, requiring fewer than 20 patients, and each patient acts as their own control [22] Competitive Landscape - Current standard of care, Trikafta, has shown significant improvements but still leaves many patients below normal CFTR function [26] - Sionna's approach aims to provide additional options for the two-thirds of patients not achieving normal function, thus addressing a critical gap in treatment [26] Financial Position - Sionna ended Q3 with $325 million in cash, providing a runway into 2028, which supports ongoing development and upcoming milestones [42] Future Outlook - The company is well-positioned to transform CF treatment with its innovative approach and has a strong team and capital to support its strategy [27][45] - Upcoming data releases in mid-2026 are anticipated to validate the efficacy of NBD1 stabilization and its potential impact on CF treatment [44][45] Additional Important Content - The company emphasizes the importance of patient feedback in determining what constitutes a clinically meaningful improvement in CF treatment [24] - Sionna's strategy includes the potential to co-position both the add-on and dual combination therapies in the market, maximizing commercial opportunities [31][32] - The historical challenges in targeting NBD1 are acknowledged, with Sionna leveraging extensive research and development to overcome these hurdles [39][40]

Financial Data and Key Metrics Changes - The company raised $219 million in its IPO in February 2025, providing financial flexibility to execute its strategy through 2028 [7] - As of Q3, the company reported having $325 million in cash, ensuring a cash runway into 2028 [46] Business Line Data and Key Metrics Changes - The company is focused on developing two NBD1 stabilizers: SION-719 for an add-on approach to the standard of care and SION-451 for a dual combination strategy [5][6] - The company aims to demonstrate a clinically meaningful improvement of at least 10 millimoles per liter in sweat chloride, which is expected to correlate with a 3-point improvement in FEV1 [34][35] Market Data and Key Metrics Changes - The cystic fibrosis market is currently valued at $12 billion and is projected to grow to $15 billion [12] - The company targets the same patient population as the standard of care, focusing on the F508del mutation, which affects 85%-90% of cystic fibrosis patients [19] Company Strategy and Development Direction - The company aims to transform the standard of care in cystic fibrosis by focusing on the NBD1 target, which has been historically considered undruggable [4][10] - The dual combination strategy is prioritized, with the goal of raising the efficacy bar through innovative combinations of therapies [6][12] Management's Comments on Operating Environment and Future Outlook - Management believes that there is a significant unmet need in the cystic fibrosis community, as two-thirds of patients on standard care do not achieve normal CFTR function [16] - The company is optimistic about its clinical development strategy and the potential to improve patient outcomes significantly [70] Other Important Information - The company has licensed three compounds from AbbVie, enhancing its portfolio with clinical data and complementary mechanisms [41][42] - The Therapeutics Development Network (TDN) of the Cystic Fibrosis Foundation is a key partner, providing access to a well-organized research network [65][66] Q&A Session Summary Question: What is the company's strategy for addressing the unmet needs in cystic fibrosis? - The company aims to improve CFTR function in patients who are currently on standard care but do not achieve normal function, focusing on the NBD1 stabilization approach [16][19] Question: How does the company plan to differentiate its products in the market? - The company plans to leverage its unique dual combination strategy and the historical data from its assays to demonstrate improved efficacy compared to existing therapies [6][70] Question: What are the expected timelines for clinical data? - The company anticipates data from its phase 2a proof of concept study in mid-2026, which will be crucial for informing future development and capital raising decisions [5][29]