Company: SION
Filing Date: 2025-11-05
Form Type: 10-Q
Source: 0001628280-25-049251
Chunk: 317

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-11-05
Form: 10-Q
Item: Part I, Item 1
Chunk 317
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BD1”). We believe stabilizing NBD1 is central to unlocking dramatic improvements in clinical outcomes and quality of life for CF patients. 

We believe our robust pipeline of NBD1 stabilizers and complementary CFTR modulators provide multiple potential pathways to achieving our goal, either in combination with each other to produce a proprietary dual combination CF therapy, or an NBD1 stabilizer in combination with the current standard of care for CF. 

In June 2025, we announced positive topline data from our two randomized, double-blinded, placebo-controlled Phase 1 clinical trials evaluating SION-719 and SION-451, our lead NBD1 stabilizer product candidates, in over 200 healthy volunteers, and our plans to advance both compounds to the next phase of clinical development. The trials assessed the safety, tolerability, and pharmacokinetics ("PK") of single and multiple ascending doses of each product candidate, as well as food effect and tablet bioequivalence. 

Both SION-719 and SION-451 were generally well tolerated in these trials, with no serious adverse events, treatment emergent adverse events that led to discontinuation of drug, or dose-limiting toxicities observed. The Phase 1 data also supported the use of a tablet formulation in future trials and indicated that both compounds could be dosed in a fed or fasted state. Both NBD1 stabilizers met target exposure thresholds. Based on the Phase 1 data and our preclinical CF human bronchial epithelial ("CFHBE") model, we believe our NBD1 stabilizers have the potential to provide clinically meaningful benefit, including the potential to restore CFTR function up to wild-type levels, when SION-719 is administered as an add-on to the standard of care or when SION-451 is used in proprietary dual combinations with one of our complementary modulators. 

In October 2025, we announced the initiation of a Phase 2a proof-of-concept trial in CF patients evaluating SION-719 as an add-on to the standard of care.  The Phase 2a trial, called PreciSION CF, is designed to evaluate the safety, tolerability, and PK of SION-719 when administered with the standard of care for CF, Vertex Pharmaceuticals, Inc.'s Trikafta, and to assess change in CFTR function as measured by sweat chloride levels. Prior to initiation, we completed a drug-drug interaction study, which confirmed SION-719 can be dosed with Trika