Welcome to our dedicated page for Sionna Therapeutics SEC filings (Ticker: SION), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Our SEC filing database is enhanced with expert analysis from Rhea-AI, providing insights into the potential impact of each filing on Sionna Therapeutics's stock performance. Each filing includes a concise AI-generated summary, sentiment and impact scores, and end-of-day stock performance data showing the actual market reaction. Navigate easily through different filing types including 10-K annual reports, 10-Q quarterly reports, 8-K current reports, proxy statements (DEF 14A), and Form 4 insider trading disclosures.
Designed for fundamental investors and regulatory compliance professionals, our page simplifies access to critical SEC filings. By combining real-time SEC filing updates, Rhea-AI's analytical insights, and historical stock performance data, we provide comprehensive visibility into Sionna Therapeutics's regulatory disclosures and financial reporting.
Sionna Therapeutics reported fourth quarter and full year 2025 results, highlighting progress in its cystic fibrosis pipeline and a strengthened balance sheet. The company recorded a net loss of $20.4 million for the quarter and $75.3 million for the year ended December 31, 2025.
Research and development expenses were $15.2 million in the quarter and $60.3 million for the year, while general and administrative expenses reached $8.4 million and $28.7 million, respectively, reflecting expanded operations after its upsized IPO. Cash, cash equivalents and marketable securities totaled $310.3 million at year-end, which Sionna expects will fund operations into 2028.
The company is running a Phase 2a proof-of-concept trial of NBD1 stabilizer SION-719 as an add-on to standard of care in cystic fibrosis, and a Phase 1 dual combination trial of SION-451 with complementary CFTR modulators, with topline data from both trials anticipated in mid-2026.
Sionna Therapeutics director-affiliated entity records stock sales linked to OrbiMed funds. An investment vehicle, OrbiMed Private Investments VIII, LP, associated with reporting person Peter A. Thompson and OrbiMed Advisors, sold 1,890 shares of Sionna Therapeutics common stock at $44.57 on February 2, 2026.
The same entity sold an additional 29,063 shares at $44.58 on February 3, 2026, leaving 3,530,702 shares of Sionna common stock indirectly beneficially owned after the transactions. The filing notes that the reporting person and related OrbiMed entities disclaim beneficial ownership except to the extent of any pecuniary interest.
OrbiMed-related entities reported insider sales of Sionna Therapeutics common stock. On February 2, 2026, OrbiMed Private Investments VIII, LP sold 1,890 shares at $44.57 per share. On February 3, 2026, it sold an additional 29,063 shares at $44.58 per share.
After these transactions, 3,530,702 shares of Sionna common stock were reported as beneficially owned indirectly. The Form 4 was jointly filed by OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC, which may be deemed to share voting and investment power through their roles over OrbiMed Private Investments VIII, LP, while each disclaims beneficial ownership except to the extent of any pecuniary interest.
TPG-affiliated investment entities that are 10% owners of Sionna Therapeutics, Inc. reported an indirect sale of 250,000 shares of common stock on January 22, 2026. The shares were sold at a price of $40 per share under transaction code "S," which indicates a sale.
After this transaction, entities associated with the reporting group indirectly held 6,494,962 shares of Sionna common stock through The Rise Fund Sling, L.P. and The Rise Fund Sling II, L.P. The filing explains that the reporting persons may be deemed to beneficially own these securities only to the extent of their direct or indirect pecuniary interests and they expressly disclaim beneficial ownership beyond those economic interests.
SION filed a Form 144 for a planned stock sale. A holder has notified the SEC of an intention to sell 195,667 shares of SION common stock, $0.001 par value per share, through Goldman Sachs & Co. LLC on or about 01/22/2026 on the Nasdaq Global Market. The filing lists an aggregate market value of $8,173,010.59 for these shares and notes that there were 44,628,788 shares of common stock outstanding at the time of the notice. The seller’s shares were originally acquired from the issuer on 02/10/2025 for cash and/or upon the automatic conversion of preferred stock into common stock.
SION filed a notice of proposed sale of restricted or control securities under Rule 144. The filing covers up to 54,333 shares of common stock, $0.001 par value per share, to be sold through Goldman Sachs & Co. LLC on the Nasdaq Global Market. The shares have an aggregate market value of $2,269,489.41 based on the filer’s calculation, and the planned sale date is listed as 01/22/2026.
The common stock to be sold was originally acquired on 02/10/2025 through the automatic conversion of preferred stock of the issuer into common stock, with 1,208,364 shares acquired in that conversion. The filing also notes that 44,628,788 shares of the issuer’s common stock were outstanding, providing context for the size of the planned sale.
Sionna Therapeutics, Inc. reported that its Chief Medical Officer, Charlotte McKee, received a grant of a non-qualified stock option on January 2, 2026. The option covers 155,700 shares of common stock with an exercise price of $39.21 per share and an expiration date of January 1, 2036.
All 155,700 derivative securities are shown as beneficially owned directly following the transaction. According to the footnote, the shares underlying this option vest in 48 equal monthly installments after January 2, 2026, and each monthly vesting is conditioned on McKee’s continued service on the applicable vesting date.
Sionna Therapeutics Chief Business Officer Caroline Stark Beer was granted a non-qualified stock option for 139,340 shares of common stock. The option was awarded on January 2, 2026 with an exercise price of $39.21 per share. All 139,340 derivative securities are reported as directly owned following the transaction.
The shares underlying this option vest in forty-eight equal monthly installments after January 2, 2026, and each monthly vesting requires her continued service on that date. This filing reflects an equity compensation award rather than a sale of existing shares.
Sionna Therapeutics, Inc. (SION) reported insider activity on a Form 4 involving RA Capital–affiliated entities and individuals who are listed as directors and, in some cases, 10% owners. On 11/20/2025 and 11/21/2025, these reporting persons sold multiple small blocks of Sionna common stock in open-market transactions.
The weighted average sale prices ranged from about $39.40 to $40.51 per share, with examples including 9,924 shares sold at a weighted average price of $39.50 and 801 shares sold at a weighted average price of $39.89. After these trades, the reported beneficial holdings for the various RA Capital funds and accounts remained large, such as 6,897,623 shares for one fund and over 2.1 million shares for another, as disclosed in the table.
Sionna Therapeutics (SION) reported insider activity on a Form 4 showing that RA Capital–affiliated entities, which are identified as both directors and 10% owners, sold shares of Sionna common stock over several days. On November 17, 2025, they executed multiple sales, including a sale of 17,913 shares of common stock at a weighted average price of $40.2 per share, in transactions within a price range of $40.00 to $40.85.
Additional sales took place on November 17–19, 2025 at weighted average prices described in the footnotes as ranging from $39.40 to $42.13 per share, all through various RA Capital funds and accounts. The filing notes that detailed breakdowns of the individual trade prices within each range are available upon request, and that the RA Capital entities and individuals disclaim beneficial ownership beyond their economic interest.