This section highlights FDA-related milestones and regulatory updates for drugs developed by Sionna Therapeutics (SION).
Over the past two years, Sionna Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
SION-719 and SION-451. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
SION-719 FDA Regulatory Timeline and Events
SION-719 is a drug developed by Sionna Therapeutics for the following indication: cystic fibrosis transmembrane conductance regulator (CFTR) protein.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- SION-719
- Announced Date:
- April 27, 2026
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, Inc. announced the completion of enrollment in the PreciSION CF Phase 2a proof-of-concept (POC) trial.
AI Summary
Sionna Therapeutics announced completion of enrollment in the PreciSION CF Phase 2a proof-of-concept trial. The study tests a targeted therapy for people with cystic fibrosis, and closing enrollment marks an important development milestone for the program.
The Phase 2a trial is designed to evaluate safety, tolerability and early signs of effectiveness. Patients enrolled represent the trial’s defined population and have finished dosing or are in follow-up. Assessments include clinical measures and biomarkers collected during the study, which the team will clean and analyze as part of the final data review.
Sionna said it will review the data and report results when available. Those results will guide decisions about further development, potential larger trials, and next steps toward bringing the approach to more people with cystic fibrosis.
Read Announcement- Drug:
- SION-719
- Announced Date:
- October 21, 2025
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, announced initiation of the PreciSION CF Phase 2a proof-of-concept (POC) trial evaluating SION-719, a first-in-class nucleotide binding domain 1 (NBD1) stabilizer, when added to Trikafta® (elexacaftor/tezacaftor/ivacaftor), the current standard of care (SOC) in CF.
Read Announcement- Drug:
- SION-719
- Announced Date:
- June 4, 2025
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, announced positive data from its Phase 1 clinical trials of SION-719 and SION-451, the company's first-in-class nucleotide-binding domain 1 (NBD1) stabilizers, in healthy volunteers.
AI Summary
Sionna Therapeutics announced positive Phase 1 data for its first-in-class NBD1 stabilizers, SION-719 and SION-451, in healthy volunteers. The trials showed that both compounds were generally well tolerated and successfully reached the desired pharmacokinetic targets established in preclinical models. These encouraging results support the potential of the stabilizers to improve CFTR function in cystic fibrosis patients, either as an add-on to the standard of care or in combination with complementary modulators.
Based on these findings, Sionna plans to advance SION-719 into a Phase 2a proof-of-concept trial in cystic fibrosis patients and to initiate a Phase 1 dual combination trial with SION-451 in healthy volunteers. The positive outcomes have reinforced the company’s commitment to developing innovative treatments that address unmet needs in cystic fibrosis care.
Read Announcement- Drug:
- SION-719
- Announced Date:
- May 22, 2025
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, Inc. announced that preclinical data assessing combinations of Sionna's nucleotide-binding domain 1 (NBD1) stabilizers, SION-451 and SION-719, with complementary Sionna CFTR modulators, galicaftor (SION-2222) and SION-109, will be featured in an oral presentation at the European Cystic Fibrosis Society's (ECFS) 48th European Cystic Fibrosis Conference, being held June 4-7, 2025 in Milan, Italy.
AI Summary
Sionna Therapeutics has announced it will present new preclinical data at the European Cystic Fibrosis Society’s 48th Conference in Milan, Italy, from June 4‑7, 2025. The study examines how combining their NBD1 stabilizers, SION‑451 and SION‑719, with complementary CFTR modulators, galicaftor (SION‑2222) and SION‑109, can work together to fully correct the defective ΔF508‑CFTR protein found in cystic fibrosis.
Scheduled for an oral presentation on June 6, 2025, the findings aim to show that this synergistic approach may restore normal CFTR function. The research offers valuable insights into developing more effective treatments, potentially improving patient outcomes and quality of life for those living with cystic fibrosis.
Read Announcement
SION-451 FDA Regulatory Events
SION-451 is a drug developed by Sionna Therapeutics for the following indication: cystic fibrosis transmembrane conductance regulator (CFTR) protein.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- SION-451
- Announced Date:
- October 24, 2025
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, Inc. announced data presented at the 2025 North American Cystic Fibrosis Conference (NACFC) being held in Seattle, Washington October 22-25.
AI Summary
On October 24, 2025, Sionna Therapeutics presented new Phase 1 and preclinical data at the 2025 North American Cystic Fibrosis Conference (NACFC) in Seattle (Oct 22–25). The Phase 1 trials of SION-719 and SION-451 enrolled over 200 volunteers and showed both NBD1 stabilizers were well tolerated, exceeded key pharmacokinetic targets, and supported a tablet formulation that can be dosed with or without food. These data give momentum for the ongoing Phase 2a proof-of-concept study in cystic fibrosis patients, with mid-2026 trial readouts expected.
New preclinical studies demonstrated that Sionna’s NBD1 stabilizers restored the half-life of the F508del-CFTR protein up to levels seen in the wild-type CFTR. This effect was observed even when the stabilizers were used alone and suggests a unique mechanism that could improve CFTR stability and function. Sionna plans to advance these compounds in combination with complementary modulators to further enhance clinical benefit for people with CF.
Read Announcement- Drug:
- SION-451
- Announced Date:
- August 25, 2025
- Indication:
- cystic fibrosis transmembrane conductance regulator (CFTR) protein
Announcement
Sionna Therapeutics, announced that the first subjects have been dosed in a Phase 1 trial evaluating SION-451, a first-in-class nucleotide binding domain 1 (NBD1) stabilizer, in proprietary dual combinations with SION-2222 (galicaftor), a transmembrane domain 1 (TMD1)-directed CFTR corrector, and with SION-109, an intracellular loop 4 (ICL4)-directed CFTR corrector.
AI Summary
Sionna Therapeutics announced dosing of first subjects in a Phase 1 trial of SION-451, a first-in-class nucleotide binding domain 1 (NBD1) stabilizer, combined with SION-2222 (galicaftor), a transmembrane domain 1 (TMD1) corrector, and with SION-109, an intracellular loop 4 (ICL4) corrector.
The randomized, double-blind, placebo-controlled trial in healthy volunteers will assess safety, tolerability, and pharmacokinetics of each dual combination. Topline data are expected mid-2026 and will guide selection of a combo for a planned Phase 2b trial in people with cystic fibrosis.
Earlier Phase 1 and preclinical studies showed SION-451 was generally well tolerated, reached target concentrations, and could restore CFTR function toward wild-type levels when paired with complementary modulators.
“Our research on NBD1 has led to these first NBD1-anchored dual combinations in clinical trials, aiming to revolutionize CF treatment,” said Charlotte McKee, Sionna’s Chief Medical Officer.
Read Announcement
