Sionna Therapeutics is a clinical-stage biopharmaceutical company focused on developing novel medicines to treat cystic fibrosis by targeting the CFTR protein's nucleotide binding domain 1 to restore normal ion channel function and improve patient outcomes.

The company generates revenue through the advancement and potential commercialization of its pipeline of drug candidates, which are designed to be used either as monotherapy or in combination therapies for cystic fibrosis patients, with no current revenue from product sales as all candidates remain in clinical development.

The company operates through the following segments: NBD1 Stabilizer Program and Complementary Modulator Programs.

• The NBD1 Stabilizer Program focuses on developing small molecule therapies that directly stabilize the nucleotide binding domain 1 of the CFTR protein, with lead candidates SION-719 and SION-451 currently in Phase 2a and Phase 1 dual combination trials respectively, aiming to correct the F508del mutation by improving CFTR folding, trafficking, and channel function when used alone or in combination with standard of care or complementary modulators.

• The Complementary Modulator Program includes a pipeline of CFTR correctors and potentiators designed to work synergistically with NBD1 stabilizers, featuring SION-2222 (TMD1-directed corrector), SION-109 (ICL4-directed corrector), SION-2851 (TMD1-directed corrector), and SION-3067 (potentiator), all of which target distinct regions of the CFTR protein to enhance trafficking and channel gating activity in preclinical and clinical models.

Sionna Therapeutics positions itself as an innovator in the cystic fibrosis treatment landscape by focusing on the historically undruggable NBD1 domain, leveraging over a decade of founder research and a proprietary CFHBE preclinical model to differentiate its approach from incumbent therapies like Vertex’s Trikafta and Alyftrek, which do not directly stabilize NBD1 and leave a significant portion of patients with suboptimal CFTR function.

The company serves patients diagnosed with cystic fibrosis, particularly those with the F508del mutation, which accounts for approximately 90% of the CF population, with no specific customer names disclosed as the business remains in preclinical and clinical development stages focused on patient populations rather than commercial clients.