Company: SION
Filing Date: 2025-03-20
Form Type: 10-K
Source: 0002036042-25-000005
Chunk: 30

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-03-20
Form: 10-K
Item: Item 1
Chunk 30
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, we licensed SION-2851 from AbbVie in July 2024. SION-2851 is a potent TMD1-directed corrector that has completed a Phase 1 SAD trial in 16 healthy volunteers. The trial was conducted by AbbVie and Galapagos in Belgium in 2018. The primary endpoint was safety and tolerability, assessed by the number of subjects with adverse events. Based on its mechanism of action and preclinical studies, we believe it may be potentially synergistic with NBD1 stabilizers.

ICL4 Program—SION-109

We are also advancing SION-109, which targets the ICL4 interface, for development in combination with an NBD1 stabilizer.

In December 2024, we completed a randomized, double blind, placebo-controlled Phase 1 clinical trial of SION-109 in healthy subjects, following clearance of its Investigational New Drug application ("IND")  by the U.S. Food and Drug Administration (the "FDA") in June 2023. The trial was conducted in the U.S. and was designed to evaluate the safety, tolerability and PK profile of single and multiple ascending doses of SION-109, administered as an oral suspension. In a Part C of the Phase 1 trial, we evaluated the effect of food on PK and the bioequivalence of a tablet formation compared to the oral suspension used in the Phase 1 SAD and MAD trials.

102 healthy adult subjects were dosed in this Phase 1 trial. The trial was designed to enroll 8 subjects, randomized 3:1 active:placebo, to each dosing cohort. Six SAD cohorts evaluated single doses from 50 mg to 400 mg. Five MAD cohorts evaluated from 50 mg to 150 mg BID over 10 dosing days. 15 subjects enrolled in the open-label food effect and tablet bioequivalence part evaluating 100 mg single doses each of suspension fasted, tablet fasted, and tablet fed. 

SION-109 was generally well tolerated at all dose levels administered in all parts of this Phase 1 trial. A summary table of reported TEAEs is shown in Figure 26 below. There were no SAEs, and most TEAEs were mild to moderate (Grade 1 or Grade 2). No TEAEs led to the discontinuation of trial drug, and no dose-limiting TEAEs were observed. Sporadic increases in potassium were observed that were determined to be