The Sionna Therapeutics, Inc. (Nasdaq: SION) SEC filings page on Stock Titan provides access to the company’s regulatory disclosures as filed with the U.S. Securities and Exchange Commission. Sionna describes itself as a clinical-stage biopharmaceutical company focused on developing CFTR-targeted therapies for cystic fibrosis, and its filings offer detail on this business and its financial position.
Among the key documents available are current reports on Form 8-K, where Sionna furnishes press releases announcing quarterly financial results and business highlights. For example, the company has used Form 8-K to present information on research and development expenses, general and administrative expenses, net loss, cash and cash equivalents, and progress across its clinical pipeline of NBD1 stabilizers and complementary CFTR modulators.
In addition to 8-Ks, investors typically look to annual reports on Form 10-K and quarterly reports on Form 10-Q for broader discussions of risk factors, research and development activities, and the company’s focus on cystic fibrosis therapies. These filings can also describe Sionna’s status as an emerging growth company, its operating segment dedicated to CF drug development, and other structural aspects of the business.
Stock Titan enhances access to SION filings by pairing real-time updates from the EDGAR system with AI-powered summaries that explain the significance of each document in clear language. Users can quickly identify items related to clinical trial progress, financial condition, and other material events, and can review insider and management-related disclosures where applicable. This page serves as a central location for reviewing Sionna’s regulatory history and understanding how its CF-focused strategy is reflected in formal SEC documents.
OrbiMed-affiliated funds reported open-market sales of Sionna Therapeutics, Inc. common stock. OrbiMed-related entities sold 52,397 shares on April 17 at $44.68 per share and 2,948 shares on April 18 at $44.52 per share, under a pre-arranged Rule 10b5-1 trading plan. After these indirect transactions through OrbiMed Private Investments VIII, LP, the reporting entities continued to hold 2,964,774 shares of Sionna Therapeutics common stock.
OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC filed an amended ownership report on Sionna Therapeutics, Inc. They report shared voting and dispositive power over 2,967,722 shares of common stock, representing 6.6% of Sionna’s 44,998,073 outstanding shares as stated in the company’s recent annual report.
The filing notes that this amendment reflects a decrease of more than 1% in beneficial ownership following recent sales by OrbiMed Private Investments VIII, L.P. The OrbiMed entities manage these holdings through their investment structures and retain discretion over voting and disposition of the shares.
Sionna Therapeutics, Inc. director Peter A. Thompson reported indirect open-market sales of a total of 510,583 shares of common stock in three transactions. The shares were sold at prices between $44.51 and $45.34 per share pursuant to a Rule 10b5-1 trading plan.
The securities are held of record by OrbiMed Private Investments VIII, LP, an investment fund advised by OrbiMed entities with which Thompson is affiliated. Following these transactions, 3,020,119 shares of common stock remain indirectly held, reflecting a continuing sizable position.
OrbiMed-affiliated funds reported open-market sales of Sionna Therapeutics, Inc. common stock. OrbiMed entities sold a total of 510,583 shares over three days at prices between $44.51 and $45.34 per share under a pre-arranged Rule 10b5-1 trading plan, and continued to hold 3,020,119 shares indirectly after the latest transaction.
The shares are held of record by OrbiMed Private Investments VIII, LP, with OrbiMed Capital GP VIII LLC and OrbiMed Advisors LLC potentially deemed beneficial owners through their control relationships, subject to customary pecuniary-interest and beneficial-ownership disclaimers.
Sionna Therapeutics, Inc. Chief Legal Officer Jennifer Fitzpatrick reported an option exercise and share sale. On March 5, 2026, she exercised a non-qualified stock option for 10,250 shares of common stock at $6.11 per share and immediately sold the same number of shares in an open-market transaction at a weighted average price of $33.8555 per share.
The sale was automatically executed under a Rule 10b5-1 trading plan adopted on June 5, 2025. The shares were sold in multiple trades at prices ranging from $32.56 to $34.83. Following these transactions, she reported 50,935 option shares remaining from this grant and no directly held common shares from this transaction.
Sionna Therapeutics, Inc. registered up to $250,000,000 of common stock for sale under an at-the-market sales agreement with Leerink Partners dated March 2, 2026.
The shelf prospectus is an automatic Form S-3 registration that permits one or more offerings of common stock, preferred stock, debt securities, warrants and units; specific terms will be provided in prospectus supplements. The sales agreement permits ongoing sales from time to time after effectiveness and Leerink may earn up to 3.0% commission on gross sales.
Sionna Therapeutics, Inc. filed its Annual Report describing its strategy as a clinical-stage biopharmaceutical company focused on cystic fibrosis (CF). The company aims to “normalize” CFTR protein function by directly stabilizing nucleotide binding domain 1 (NBD1), long viewed as an undruggable but critical domain affected by the common F508del mutation.
Sionna’s pipeline centers on two NBD1 stabilizers, SION-719 and SION-451, and several complementary CFTR modulators designed for use in proprietary combinations or as add-ons to current standard-of-care regimens such as Trikafta. SION-719 is in a Phase 2a proof-of-concept CF trial as an add-on to Trikafta, after Phase 1 data in healthy volunteers showed it was generally well tolerated with pharmacokinetics supportive of twice-daily dosing.
SION-451 has completed a single-agent Phase 1 study, also showing generally favorable safety and exposure consistent with twice-daily dosing, and is now being tested in dual combinations with correctors SION-2222 and SION-109 in a Phase 1 trial. Earlier AbbVie- and Galapagos-run studies of SION-2222 and potentiator SION-3067 demonstrated improvements in sweat chloride and lung function when used together.
The report emphasizes Sionna’s translational approach using a cystic fibrosis human bronchial epithelial (CFHBE) model, which the company notes has closely tracked clinical outcomes for approved CFTR modulators. Preclinical data suggest that combining Sionna’s NBD1 stabilizers with complementary modulators or Trikafta can raise CFTR activity to near wild-type levels in vitro, which the company believes could translate into clinically meaningful improvements in sweat chloride and lung function for patients who remain inadequately served by existing therapies.
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.