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Sionna Therapeutics

SION Rare disease Lead: Phase 2 4 Biotech Distilled articles ↓ 19 filings & releases ↓ Cash $63.3M (Jun 30, 2026) ↓ 4 verdicts ↓
Respiratory Small Molecule

Market cap $148M 45.2M shares (10-Q, Jul 31, 2026) × $3.28 close Nov 6, 2026

Most recent annual filing: 2026-03-02

Catalyst timeline

1 trackedQuarter catalyst calendar →
  1. SION-451 dual combination Ph2b start2027SION-451 dual combination Ph2b start, 2027, routine

Bar width shows how precise the guidance is — a pin is a stated date, a wide band a six-month window. Deeper blue means more of the thesis rides on the event; it is not a view on the stock.

Pipeline (5 active programs)

Discontinued (1)

Capital (as filed)

Cash
$63.3M cash and cash equivalents · Jun 30, 2026 (10-Q)
Operating cash flow
−$22.2M quarter Mar 31, 2026 → Jun 30, 2026, year-to-date difference (10-Q)
As stated in coverage
$268M cash, runway 2H 2029 per the update of Sep 22, 2026 — the company's own words as read there, not the filed figure

Cash, investments and operating cash flow are the company's own XBRL facts as filed with the SEC, each shown with its period end and tag. As-stated figures come from the company's own words as read in Biotech Distilled coverage, dated, and routinely count securities and planned financing that a balance sheet does not. Offering rows are the SEC cover pages as filed. Not investment advice. Figures as of Nov 7, 2026.

Biotech Distilled coverage (4)

Articles open on Substack. Some are subscriber-only; those marked ★ Distilled Pro are for Distilled Pro members.

Verdict history (4 calls)

Every verdict Biotech Distilled has published on Sionna Therapeutics, oldest first — the full history, never a selection. How calls are scored: the track record.

  1. 2026-07-24 Watch Sionna Therapeutics (SION) — Scientific Deep Dive for SION-719, SION-451 and the NBD1 Franchise Genuinely novel NBD1 science with elite backing and funded balance sheet, but zero human efficacy data and a stock up 195% into a 16-patient binary makes the disciplined move waiting for the PreciSION CF readout before initiating.
  2. 2026-08-11 Avoid UPDATE: Sionna Therapeutics (SION) - The Coin Landed on Tails PreciSION CF delivered a -1.0 mmol/L placebo-adjusted sweat chloride change (p=0.7) against a ≥10 mmol/L bar, failing the mechanism's first and only human efficacy test, with the translational model now falsified and no clear path forward.
  3. 2026-09-15 Avoid UPDATE: Sionna Therapeutics (SION) - The Subgroup Resurrection Post hoc exclusion of 3 of 15 patients produces an encouraging -8.6 mmol/L subset result and a plausible ivacaftor-interference hypothesis, but nothing has been proven in a patient and the confirming AscenSION CF trial is an open-label switch study not starting until Q1 2027.
  4. 2026-09-23 Avoid UPDATE: Sionna Therapeutics (SION) - The Smart Money Took the Bounce RA Capital sold 3.45M shares at $6.32 into the subgroup rally, cutting its stake from ~22.9% to 14.3%, signaling the best-informed holder chose the bounce over waiting for AscenSION CF data, while the underlying science remains unchanged and unproven.

Every verdict Biotech Distilled has published on this company, in order, with the post it came from — the full history, never a selection. Position figures are the same ones shown on /track-record, computed by the same method. Editorial opinion, not investment advice.

Filings & releases (19)

SEC filings from EDGAR and press releases captured from the company's investor-relations site, newest first. Releases captured from Aug 6, 2026; filings from March 2026. Summaries come from the BD update that read the document; "BD extracted" counts point at the pipeline table above. All companies →

4 more filings (13G holder notices, S-8, proxy material, SEC correspondence …)