1. The Vertex Pharmaceuticals of tomorrow, aiming to normalize CFTR function for cystic fibrosis patients.

2. Like Vertex Pharmaceuticals, but focused on developing next-generation cystic fibrosis treatments by tackling a previously "undruggable" target.

3. A company striving to be the next Vertex Pharmaceuticals in cystic fibrosis, through a novel, more foundational approach to treatment.

• SION-719: A clinical-stage small molecule NBD1 stabilizer being developed to treat cystic fibrosis.
• SION-451: A clinical-stage small molecule NBD1 stabilizer being developed to treat cystic fibrosis.
• Galicaftor (SION-2222): An in-licensed clinical-stage CFTR modulator targeting TMD1, intended for combination therapies in cystic fibrosis.
• SION-109: A clinical-stage CFTR modulator targeting the ICL4 region, intended for combination therapies in cystic fibrosis.

Sionna Therapeutics (SION) is a clinical-stage biopharmaceutical company focused on developing novel medicines for cystic fibrosis. As of the provided description, the company is in the research and development phase, conducting Phase 1 clinical trials for its drug candidates SION-719 and SION-451. The company does not currently have any approved products on the market and, therefore, does not have major customers or generate revenue from product sales.

Upon successful development and regulatory approval, Sionna Therapeutics' products would ultimately be prescribed to individuals living with cystic fibrosis.

• AbbVie Global Enterprises Ltd. (ABBV)

Mike Cloonan, President and Chief Executive Officer

Mike Cloonan is a respected biotech leader with over 20 years of biopharma experience. He most recently served as Chief Operating Officer at Sage Therapeutics, where he led all business functions and G&A functions. Prior to Sage, he spent 14 years at Biogen in various business and commercial roles, culminating as Senior Vice President, U.S. Commercial. He joined Sionna in May 2021.

Elena Ridloff, C.F.A., Chief Financial Officer & Head of Corporate Development

Elena Ridloff has over 20 years of experience in finance and the life sciences industry. She most recently served as Executive Vice President and Chief Financial Officer for Acadia Pharmaceuticals, where she was responsible for leading corporate finance, accounting, investor relations, corporate affairs, and government affairs functions. During her tenure at Acadia, she played a critical role in the organization's commercial, business development, and pipeline growth, including successfully raising $600 million in capital. Prior to Acadia, she was Vice President, Investor Relations at Alexion Pharmaceuticals. Elena also served as Chief Executive Officer of BIOVISIO, an independent consulting firm, and was a Managing Director at Maverick Capital, a hedge fund, responsible for investments in the biotechnology, pharmaceutical, and life science sectors. She serves on the boards of directors of Kymera Therapeutics, Inc. and previously Kronos Bio, Inc.

Charlotte McKee, M.D., Chief Medical Officer

Dr. Charlotte McKee serves as the Chief Medical Officer of Sionna Therapeutics.

Caroline Stark Beer, Chief Business Officer

Caroline Stark Beer brings more than two decades of experience in the life sciences industry. She most recently served as Chief Business Officer at Jnana Therapeutics, where she led business and corporate development, alliance management, legal, new product planning, and communications. She played a key role in guiding Jnana Therapeutics through its acquisition by Otsuka Pharmaceutical.

Greg Hurlbut, Ph.D., Co-Founder and Senior Vice President, Discovery Research

Dr. Greg Hurlbut is a co-founder of Sionna Therapeutics. Prior to co-founding Sionna, he spent over a decade extensively researching the NBD1 target as a research leader at Sanofi SA.

The key risks to Sionna Therapeutics' business are:

1. Clinical Development and Regulatory Approval Risk: Sionna Therapeutics' ability to achieve its mission of revolutionizing cystic fibrosis treatment is highly dependent on the successful development, regulatory approval, and commercialization of its novel NBD1 stabilizers and complementary CFTR modulators. Its lead NBD1 stabilizers, SION-719 and SION-451, are currently in Phase 1 trials with healthy subjects, an early stage in drug development. Historically, NBD1 has been considered "undruggable," which highlights the inherent difficulties and high risk of failure associated with developing therapies targeting this domain. Significant delays, unexpected adverse events, or a lack of demonstrated efficacy in later-stage clinical trials (Phase 2 and 3) would severely impact the company's prospects, especially given the high attrition rate of drug candidates in clinical development.
2. Market Competition and Commercialization Risk: Sionna Therapeutics operates in a competitive market for cystic fibrosis treatments, which already includes established and highly effective CFTR modulators such as Trikafta, generating substantial global revenue. The company aims to deliver "differentiated medicines" and restore CFTR function to "as close to normal as possible." However, successfully penetrating this market and gaining significant adoption will require demonstrating clinically meaningful benefits that are superior to, or significantly differentiate their products from, existing standard-of-care treatments. Failure to effectively compete with incumbent therapies or to achieve sufficient market share would hinder the company's revenue generation and growth, even if its products receive regulatory approval.

The addressable market for Sionna Therapeutics' main products, which are CFTR modulators, was approximately $10 billion worldwide in 2023 and is projected to grow to $15 billion worldwide by 2029.

Sionna Therapeutics (SION), a clinical-stage biopharmaceutical company focused on cystic fibrosis (CF), is expected to drive future revenue growth over the next 2-3 years through several key advancements and strategic initiatives:

1. Advancement of Lead NBD1 Stabilizers through Clinical Development: Successful progression of its novel nucleotide-binding domain 1 (NBD1) stabilizers, SION-719 and SION-451, from ongoing Phase 1 trials into later-stage clinical development (e.g., Phase 2 or proof-of-concept trials) will be a critical driver. The successful validation of these "undruggable" NBD1 targets, which have the potential to normalize CFTR protein function, would significantly enhance the company's valuation and attractiveness for potential partnerships, leading to milestone payments that contribute to revenue.
2. Development and Clinical Progression of Proprietary Combination Therapies: Sionna's strategy includes evaluating its NBD1 stabilizers in combination with the current standard of care, Trikafta, and determining optimal proprietary dual combinations. Positive clinical data from these combination approaches, particularly given the in-licensed galicaftor (SION-2222) has completed Phase 2, would solidify the company's competitive position. This would accelerate the potential path to market and expand the addressable patient population, laying the groundwork for substantial future revenue.
3. Establishment of Strategic Partnerships and Licensing Agreements: As a clinical-stage entity, Sionna Therapeutics can generate revenue through strategic collaborations and out-licensing agreements. Securing partnerships for its innovative CFTR modulators, especially the NBD1 stabilizers or promising combination candidates, could lead to significant upfront payments and subsequent milestone payments as development progresses, directly contributing to revenue growth within the 2-3 year timeframe.
4. Demonstration of Differentiated Efficacy and Safety Profile: While commercialization is anticipated beyond the 2-3 year horizon, demonstrating compelling clinical data within this period that showcases superior efficacy in restoring CFTR function (potentially normalizing it) and a favorable safety profile compared to existing treatments will be a crucial driver for future revenue. Such differentiation would establish a strong market advantage and lay the foundation for significant product revenue upon eventual approval.

Share Issuance

• Sionna Therapeutics completed an upsized Initial Public Offering (IPO) in February 2025, raising approximately $219.2 million in gross proceeds through the issuance of 12,176,467 shares of common stock at $18.00 per share.
• In March 2026, Sionna Therapeutics registered up to $250 million of common stock for sale under an at-the-market (ATM) sales agreement.
• The company's updated certificate of incorporation, effective prior to the IPO, authorizes the issuance of 500 million shares of common stock and 10 million shares of undesignated preferred stock.

Inbound Investments

• In March 2024, Sionna Therapeutics announced a $182 million Series C financing round.
• TPG GP A, LLC, a former 10% owner, invested $20,250,000 in February 2025 by purchasing 1,125,000 shares of Sionna Therapeutics' stock.

Capital Expenditures

• Sionna Therapeutics invested $204,000 in capital expenditures during the fourth quarter of 2025, representing a 134.5% increase from the prior quarter.
• These capital expenditures were focused on funding long-term assets and infrastructure.