Sionna Therapeutics
Develops NBD1-stabilizing and complementary CFTR modulators for cystic fibrosis.
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Profile
Develops small-molecule cystic fibrosis therapies that stabilize NBD1 and pair with complementary CFTR modulators. SION-719 is no longer advancing as an add-on after missing its Phase 2a activity endpoint; next steps for the preferred SION-451 and SION-2222 dual combination remain under evaluation, leaving the business pre-commercial and dependent on clinical validation.
Develops small-molecule cystic fibrosis therapies that stabilize NBD1, the CFTR protein domain where the common F508del mutation disrupts folding and channel function. Its portfolio pairs NBD1 stabilizers SION-451 and SION-719 with complementary modulators SION-2222, SION-109, SION-2851, and SION-3067. Structure-guided discovery and a human bronchial epithelial model guide compound selection.
Clinical priorities changed after SION-719 missed the key activity endpoint in its Phase 2a add-on trial and was dropped from that path. A healthy-volunteer trial met safety, tolerability, and pharmacokinetic objectives for SION-451 combinations; SION-451 plus SION-2222 was selected as the preferred dual combination, with next steps under evaluation.
Based in Massachusetts, the business holds worldwide commercial rights but has no product revenue or commercial organization. Progress depends on clinical validation, regulatory approval, licensed complementary-modulator rights, and third-party manufacturing.
Company facts
Key statistics
Year to date −85.1% · Average volume (30d) 3.2M
Analysts
Ratings
Target range
Latest analyst notes
| Date | Firm | Action | Prior rating | Rating | Prior target | Target |
|---|---|---|---|---|---|---|
| Aug 11, 2026 | Wedbush | Downgrade | Outperform | Neutral | ||
| Aug 11, 2026 | Guggenheim | Downgrade | Buy | Neutral | ||
| Aug 10, 2026 | BTIG | Downgrade | Buy | Neutral | ||
| Aug 10, 2026 | Guggenheim | Downgrade | Buy | Neutral | ||
| Aug 10, 2026 | Citigroup | Downgrade | Outperform | Market Perform |
Earnings
EPS
Revenue
History
| Report date | EPS est | EPS | Surprise | Revenue est | Revenue | Surprise | Next session |
|---|---|---|---|---|---|---|---|
| Aug 6, 2026Q2 FY26 | −$0.65 | −$0.66 | −1.5% | — | — | — | +4.80% |
| May 12, 2026Q1 FY26 | −$0.52 | −$0.60 | −15.4% | — | — | — | +5.32% |
| Mar 2, 2026Q4 FY25 | −$0.54 | −$0.46 | +14.7% | — | — | — | +0.50% |
| Nov 5, 2025Q3 FY25 | −$0.52 | −$0.46 | +11.5% | — | — | — | −1.94% |
Financial highlights
| 11 quarters | Q1 FY25 | Q2 FY25 | Q3 FY25 | Q4 FY25 | Q1 FY26 | Q2 FY26 | |
|---|---|---|---|---|---|---|---|
| Revenue | $0 | $0 | $0 | $0 | $0 | $0 | |
| Gross profit | $0 | −$147.0K | $0 | −$152.0K | −$154.0K | $0 | |
| Operating income | −$19.7M | −$21.9M | −$23.8M | −$23.6M | −$29.6M | −$32.5M | |
| Net income | −$16.5M | −$18.1M | −$20.3M | −$20.4M | −$26.8M | −$29.9M | |
| Diluted EPS | −$0.37 | −$0.41 | −$0.46 | −$0.46 | −$0.60 | −$0.66 | |
| Gross margin | — | — | — | — | — | — | |
| Operating margin | — | — | — | — | — | — |
Fiscal years (4-quarter sums)FY24 $0 · FY25 $0
Balance sheet, Jun 30, 2026Cash & short-term investments $211.0M · Total debt $8.1M · Total assets $283.2M · Shareholders' equity $265.8M
Dividends
No dividends on record.
Ownership
A 13F quarter can total more than the shares outstanding — sub-advisers file the same block twice, and a filer's own share count can be a quarter stale. No split is drawn from it.
Shares outstanding 45.15M · Float 26.61M · 58.9% free float
Top shareholders13F · 13D/G · Form 4
| Holder | Shares | % outstanding | Form | Filed |
|---|---|---|---|---|
| Peter Kolchinsky | 10.07M | 22.60% | 13D | Nov 7, 2025 |
| Ra Capital Management, L.P. | 9.91M | 21.94% | 13F | May 15, 2026 |
| TPG GP A, LLC | 6.49M | 14.39% | 13F | May 15, 2026 |
| Orbimed Advisors LLC | 3.53M | 7.82% | 13F | May 15, 2026 |
| Viking Global Investors LP | 3.20M | 7.10% | 13G | May 15, 2026 |
Insider tradesForm 4
| Date | Insider | Role | Shares | Avg price |
|---|---|---|---|---|
| Jul 7, 2026 | Orbimed Advisors LLC | director | −85,918 | $44.86 |
| Jul 7, 2026 | Peter A. Thompson | director | −85,918 | $44.86 |
| Jul 6, 2026 | Jennifer Fitzpatrick | officer: Chief Legal Officer | −10,250 | $43.60 |
| Jun 30, 2026 | Orbimed Advisors LLC | director | −115,844 | $45.50 |
| Jun 30, 2026 | Peter A. Thompson | director | −115,844 | $45.50 |
Peers
- Vertex Pharmaceuticals
Dominates approved CFTR modulators and standard-of-care CF therapy
- Arcturus Therapeutics
Inhaled CFTR mRNA program for modulator-nonresponsive CF
- 4D Molecular Therapeutics
Aerosol AAV CFTR gene therapy targets CF lung disease
- Krystal Biotech
Nebulized genetic medicine seeks CFTR expression in CF lungs
- Intellia Therapeutics
CRISPR collaborator for lung-delivered CF gene correction
CompareAfter-hours close
| Company | Price | Change | |||||
|---|---|---|---|---|---|---|---|
| Sionna Therapeutics | $5.89 | +0.44% | $265.0M | — | — | — | — |
| Vertex Pharmaceuticals | $540.78 | −0.17% | $137.48B | 31.5 | 27.8 | 10.9 | +12.5% |
| Arcturus Therapeutics | $15.10 | −0.59% | $431.7M | — | — | 18.1 | −87.9% |
| 4D Molecular Therapeutics | $14.67 | +0.07% | $766.9M | — | — | 8.3 | +25,106.7% |
| Krystal Biotech | $351.46 | +0.05% | $10.36B | 44.0 | 41.3 | 23.5 | +24.1% |
| Intellia Therapeutics | $12.87 | −0.01% | $1.80B | — | — | 30.2 | −46.2% |
| Median | 37.8 | 34.6 | 18.1 | +12.5% |