Welcome to our dedicated page for X4 Pharmaceuticals SEC filings (Ticker: XFOR), 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.
X4 Pharmaceuticals, Inc. filings document a rare-disease biopharmaceutical issuer with commercial activity for XOLREMDI and development work around mavorixafor. Its 8-K reports cover operating and financial results, material agreements, restructuring actions, executive and board changes, and capital-structure updates involving common stock, pre-funded warrants, registration rights, and equity purchase arrangements.
Proxy materials describe shareholder voting matters, board composition, committee assignments, executive compensation, equity awards, and governance procedures. The filing record also includes disclosures tied to the company’s inducement and equity incentive practices, financing arrangements, and formal reporting of material corporate events.
X4 Pharmaceuticals, Inc. (XFOR) is the subject of a Schedule 13G reporting that a group of Venrock-affiliated funds and individuals collectively beneficially own 5,555,047 shares of its common stock. This represents 5.6% of X4’s common shares, based on 99,146,743 shares outstanding as of July 31, 2026.
The reported holdings consist of 2,553,145 shares held by Venrock Healthcare Capital Partners III, L.P., 255,515 shares held by VHCP Co-Investment Holdings III, LLC, and 2,746,387 shares held by Venrock Healthcare Capital Partners EG, L.P. The reporting entities and individuals share voting and dispositive power over these shares as a group.
X4 Pharmaceuticals, Inc. (XFOR) furnished an updated corporate presentation outlining the status of mavorixafor (XOLREMDI), its oral CXCR4 antagonist, and its strategy in chronic neutropenia and WHIM syndrome. Mavorixafor is already approved for WHIM syndrome in the U.S. and EU, and X4 is focusing on a pivotal Phase 3 4WARD trial in chronic neutropenia.
The presentation states that full enrollment in the 4WARD study is expected in Q4 2026, with top-line data in H1 2028 and potential U.S. FDA approval in late 2028 or early 2029. The trial plans to enroll 126 patients with moderate or severe chronic neutropenia and assesses ANC response and annualized infection rate as co-primary endpoints. Phase 2 data showed increases in mean absolute neutrophil counts to normal levels and substantial reductions in G-CSF use, with mainly mild to moderate gastrointestinal adverse events.
The company highlights a U.S. target market of about 15,000 primary chronic neutropenia patients with moderate and severe disease, positioning mavorixafor as monotherapy or in combination with G-CSF. X4 reports raising $240 million from institutional investors, holding $208 million of cash as of June 30, 2026, with a cash runway expected into 2029 and patent protection for mavorixafor expected through 2038.
X4 Pharmaceuticals, Inc. (XFOR) reports a positive outcome from a Type C Meeting with the U.S. Food and Drug Administration regarding its global 4WARD Phase 3 trial of mavorixafor in chronic neutropenia. The FDA agreed with X4’s analysis to reduce the 4WARD trial sample size from 176 to 126 participants while maintaining adequate overall power for the co-primary endpoints of reduced annualized infection rate and positive absolute neutrophil count (ANC) response. The FDA also indicated that the proposed safety database would be acceptable to support a potential supplemental new drug application (sNDA).
X4 states that, with support from its new clinical research organization, it expects to complete enrollment in 4WARD by the end of 2026 and to report topline data in the first half of 2028. The company highlights an estimated 15,000 patients with serious and/or recurring infections from chronic neutropenia as a potential market and notes that mavorixafor, an oral CXCR4 antagonist already available in the U.S. as XOLREMDI in a first indication, has U.S. FDA Fast Track designation for chronic neutropenia.
Perceptive Advisors LLC, Joseph Edelman, and Perceptive Life Sciences Master Fund, Ltd. report beneficial ownership of X4 Pharmaceuticals, Inc. Common Stock on an amended Schedule 13G. The Master Fund directly holds 7,933,491 shares of Common Stock and 151,515 Warrants that are immediately exercisable, for an aggregate of 8,085,006 shares deemed beneficially owned.
Based on 99,146,743 shares of Common Stock outstanding as of July 31, 2026, each Reporting Person’s beneficial ownership is 8.1%. All 8,085,006 shares are reported with shared voting and shared dispositive power, with no sole voting or dispositive power. The Warrants are subject to a 9.99% Beneficial Ownership Limitation.
Deep Track Capital and affiliates report beneficial ownership of X4 Pharmaceuticals common stock and related securities as of June 30, 2026. The group collectively reports 8,040,894 shares beneficially owned, representing 8.33% of the common stock, all with shared voting and dispositive power.
This position includes 2,162,137 Pre-Funded Warrants exercisable into common stock, subject to a 9.99% "Maximum Percentage" ownership cap that limits exercises if they would push holdings above that threshold. Ownership percentages are based on 96,481,833 shares, including 94,319,696 shares outstanding as of May 1, 2026 plus the shares issuable upon warrant exercise within the cap.
X4 Pharmaceuticals, Inc. president John Volpone reported selling 24,576 shares of common stock on August 12, 2026 at a weighted average price of $4.44 per share, in transactions ranging from $4.33–$4.55, to cover a personal income tax obligation upon settlement of a restricted stock unit award. Following these sales, he directly holds 265,305 shares, of which 193,254 shares represent restricted stock units.
X4 Pharmaceuticals, Inc. Executive Chairman Adam R. Craig reported selling 47,436 shares of common stock on August 12, 2026 in an open-market transaction at a weighted average price of $4.4445 per share, with individual trade prices ranging from $4.33 to $4.55. According to the disclosure, the sale was made to cover personal income tax obligations arising from the settlement of a restricted stock unit award. Following this transaction, Craig directly held 328,651 shares of common stock, including 193,254 shares represented by restricted stock units.
X4 Pharmaceuticals, a biopharma focused on rare hematology diseases, reported Q2 2026 revenue of $8.8 million, up from $2.0 million a year earlier, driven by license and other revenue from its Norgine partnership and higher net product sales of XOLREMDI, which reached $2.4 million. Net loss narrowed to $16.2 million from $25.7 million as research and development and general and administrative expenses declined following 2025 restructuring actions.
As of June 30, 2026, cash, cash equivalents and short‑term marketable securities totaled $208.0 million, with $40.4 million used in operating activities in the first half of 2026. Long‑term financing is anchored by the Hercules Loan Agreement, with $75.0 million of principal outstanding and total principal plus end‑of‑term payments of $77.0 million due July 1, 2027. Management expects current liquidity to fund operations and debt obligations for at least the next 12 months, while continuing to anticipate operating losses and the need to raise additional capital over time.
XOLREMDI has accelerated approval in the United States for WHIM syndrome and obtained European Commission marketing authorization in April 2026, with commercialization in Europe out‑licensed to Norgine and the approved MAA transferred in July 2026. The pivotal 4WARD Phase 3 trial in chronic neutropenia is ongoing under a new CRO, with an FDA meeting planned to revisit sample size and an enrollment update targeted by the end of the third quarter.