Here are the 8-K filings from X4 Pharmaceuticals, Inc. (XFOR) in our archive since June 2025, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
An 8-K covers material events a company has to report between its quarterly reports, so if you follow XFOR and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full XFOR filings page.
X4 Pharmaceuticals, Inc. outlined mavorixafor development in primary chronic neutropenia (PCN). The ongoing global, double-blind, placebo-controlled Phase 3 4WARD trial is designed for 126 patients; X4 expects full enrollment by the end of Q4 2026 and topline data in Q1 2028. Primary endpoints are ANC response and annualized infection rate. X4 describes potential U.S. FDA approval in late 2028 or early 2029 and states that safety and efficacy in PCN have not been established.
X4 plans to start the Phase 2b 4STEPS study in Q1 2027, evaluating G-CSF dose reduction with mavorixafor in acquired primary autoimmune and idiopathic chronic neutropenia disorders. The single-arm, open-label study has estimated enrollment of ~25 patients; topline data are expected in H1 2028, with efficacy measures including G-CSF cessation and dosage reduction at six months.
X4 cites claims analyses estimating ~15,000 symptomatic U.S. patients with ANC <1,000 cells/µL and 2+ infections in 2025, and ~95,000 patients aged 12+ with confirmed PCN and ANC <1,500 cells/µL active in 2025. For WHIM syndrome, XOLREMDI launched in the U.S. in 2024 and received European Commission approval in 2026. X4 says its cash runway is expected into 2029.
X4 Pharmaceuticals, Inc. entered into a senior secured term loan facility with K2 HealthVentures for up to $150.0 million. The lenders funded $80.0 million on October 7, 2026; up to $70.0 million more may be made available at the Borrowers’ request, subject to the Administrative Agent’s review of certain information and the Lenders’ discretionary approval. The Borrowers used part of the funded tranche to repay their Hercules facility in full for approximately $78.7 million, including $75.0 million of principal.
The loans bear cash interest at the greater of 8.55% or The Wall Street Journal prime rate plus 1.55%, and 1.0% annual paid-in-kind interest. Interest-only payments run through October 1, 2029, with extension to maturity conditional on, among other conditions, first U.S. commercial sales of mavorixafor for moderate to severe chronic neutropenia; maturity is October 1, 2030. The Lenders may convert up to $15.0 million of principal into common stock at $3.2341 per share, subject to beneficial ownership limitations. The loans are secured by substantially all Borrowers’ assets except intellectual property.
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.
X4 Pharmaceuticals appointed Kelly Gold as a Class II director effective July 1, 2026, expanding its board from five to six members. She will serve as an independent director and join the Board’s Audit Committee.
Gold is currently Chief Financial Officer of CAMP4 Therapeutics and previously held senior finance and corporate development roles at CAMP4 and Biogen, as well as investment banking roles at Deutsche Bank. She holds dual bachelor’s degrees in life sciences and mechanical engineering from Queen’s University and an MBA from MIT Sloan. X4 highlights her financial leadership, capital markets experience and scientific background as aligned with its focus on rare hematology diseases and the continued development of mavorixafor, which is approved in the U.S. and EU as XOLREMDI for WHIM syndrome.
X4 Pharmaceuticals, Inc. filed an amended current report to correct a typographical error in a prior disclosure about its Class III director nominees, confirming that Murray W. Stewart, M.D. was elected rather than Michael S. Wyzga. The filing also reports final voting results from the May 11, 2026 annual stockholder meeting.
Stockholders approved increasing the shares available under the Second Amended and Restated 2017 Equity Incentive Plan by 1,500,000 shares and ratified PricewaterhouseCoopers LLP as independent auditor for the year ending December 31, 2026. They also approved, on a non-binding basis, the compensation of the company’s named executive officers.
X4 Pharmaceuticals, Inc. reported results of its annual stockholder meeting. Stockholders approved the Second Amended and Restated 2017 Equity Incentive Plan, adding 1,500,000 shares to the pool available for equity awards. As of March 13, 2026, there were 90,919,696 common shares outstanding and entitled to vote.
Three Class III directors—Gary J. Bridger, Ph.D., Françoise De Craecker, and Michael S. Wyzga—were elected to serve until the 2029 annual meeting. Stockholders also ratified PricewaterhouseCoopers LLP as independent registered public accounting firm for the year ending December 31, 2026 and approved, on a non-binding basis, the compensation of the named executive officers.
X4 Pharmaceuticals, Inc. filed an 8-K stating it furnished a press release announcing financial results and other business highlights for the third quarter ended September 30, 2025. The release is attached as Exhibit 99.1 and incorporated by reference. The company notes the Item 2.02 information is furnished, not filed, under the Exchange Act.
X4 Pharmaceuticals announced an underwritten public offering of 45,860,000 shares of common stock at $2.90 per share and, in lieu of shares to certain investors, pre-funded warrants for 700,000 shares at $2.899 per warrant. The underwriters’ 30‑day option to purchase up to 6,984,000 additional shares was exercised in full on October 24, 2025.
The company expects net proceeds of approximately $145.6 million, after underwriting discounts, commissions, and estimated expenses. The securities were offered off an effective shelf registration, with a final prospectus supplement filed October 24, 2025. Closing is expected on October 27, 2025, subject to standard conditions. The pre-funded warrants are exercisable at any time, subject to beneficial ownership limits of 4.99% or 9.99%, adjustable up to 19.99% with 61 days’ prior notice.
X4 Pharmaceuticals is undertaking a major restructuring to focus resources on completing its 4WARD Phase 3 trial in chronic neutropenia. The plan includes reducing its workforce by approximately 50%, which is expected to generate about $13 million in annualized cost savings and result in an estimated $3.3 million of severance and related cash charges.
As part of the actions, the company terminated its Chief Operating Officer, Chief Commercial Officer, and Chief Legal & Compliance Officer effective September 15, 2025, and its Chief Medical Officer resigned effective September 16, 2025. The Board appointed John Volpone as Chief Operating Officer, and he will also continue serving as President. X4 notes that actual restructuring costs and benefits may differ from current estimates.
X4 Pharmaceuticals, Inc. reported that on August 22, 2025, directors David McGirr and R. Keith Woods resigned from its board of directors, including all board committees, effective immediately. The company stated that their resignations were not due to any disagreement regarding operations, policies, or practices.
Following these departures, Michael Wyzga was appointed chair of the board’s audit committee, and Francoise de Craecker and Gary Bridger were appointed as members of the audit committee, ensuring the committee remains staffed to oversee the company’s financial reporting and controls.
X4 Pharmaceuticals completed two related private placements that raised aggregate gross proceeds of $85,000,000. The company sold common stock and pre-funded warrants, including a separate sale of pre-funded warrants to purchase up to 17,618,041 shares for approximately $25,000,000. The earlier placement raised $60 million. The purchase price per pre-funded warrant in the second placement was $1.419, and the warrants carry an exercise price of $0.001 per share, are exercisable at any time and do not expire.
The financings closed on August 13, 2025, and X4 reported that on a fully-diluted basis shares outstanding will be approximately 87.2 million. The securities were sold in private transactions under exemptions from registration (Regulation D) and the company agreed to file a registration statement to register the resale of the issued shares and shares underlying the pre-funded warrants. Copies of the agreements and a press release are filed as exhibits.
X4 Pharmaceuticals, Inc. (XFOR) entered into a Securities Purchase Agreement to sell an aggregate of 11,040,776 shares of common stock at $1.42 per share and, for certain investors in lieu of shares, pre-funded warrants to purchase 31,234,731 shares at $1.419 each, with expected aggregate gross proceeds of approximately $60 million before fees. The pre-funded warrants include customary beneficial ownership limitations and are exercisable until fully exercised. The Company agreed to file a registration statement covering the resale of the securities promptly after closing and agreed to customary indemnities and liquidated damages (1% of the invested amount per 30-day period) if registration milestones are unmet.
The filing also discloses executive leadership turnover and new appointments. The CEO and CFO resigned effective at the announced Effective Time; the Board appointed Adam R. Craig, M.D., Ph.D. as Executive Chairman and principal executive officer, John Volpone as President and David H. Kirske as Chief Financial Officer. Each incoming executive has an employment agreement with stated base salaries, target bonuses and sizeable time- and performance-based equity awards. The Board adopted an amendment increasing inducement-plan authorized shares to 11,775,643.
X4 Pharmaceuticals, Inc. (XFOR) entered into a $40 million equity purchase agreement with Lincoln Park Capital Fund, LLC on 23 June 2025. The two-year facility allows X4 to sell newly issued common shares to Lincoln Park at the Company’s discretion.
Key mechanics
- Up to 30,000 shares per Regular Purchase, expandable to 60,000 shares when the share price is ≥ $5.00, subject to a $500,000 per-purchase cap.
- Purchase price set at 97 % of the lower of (i) the lowest trade on the purchase date or (ii) the average of the three lowest closes in the prior 10 trading days.
- Optional Accelerated and Additional Accelerated Purchases (up to 300 %/30 % of volume) follow the same 97 % pricing formula.
- Beneficial ownership cap: 4.99 % (option to lift to 9.99 % after 61 days); Exchange cap: 19.99 % of outstanding shares (≈ 1.44 million, incl. 137,099 commitment shares) unless shareholder approval or average sales price ≥ $2.67.
- X4 issued 137,099 commitment shares to Lincoln Park as a fee; no cash received for these shares.
Strategic and financial considerations
- Facility is non-exclusive; X4 may raise capital elsewhere (other than similar equity-line structures for a limited period).
- Lincoln Park is prohibited from short selling or hedging X4 stock.
- Use of proceeds: working capital and general corporate purposes.
- Company may terminate the agreement at any time without cost.
The shares are registered under the Company’s effective shelf registration (Form S-3 No. 333-273961). Copies of the Purchase Agreement, Registration Rights Agreement, and related legal opinion are filed as Exhibits 10.1, 10.2 and 5.1, respectively.