X4 Pharmaceuticals, Inc.

What they do

X4 develops and commercializes small molecule therapeutics for rare hematology diseases. Its lead asset, mavorixafor, is an oral, once-daily selective CXCR4 antagonist. XOLREMDI (mavorixafor) holds U.S. accelerated approval for patients 12 and older with WHIM syndrome, and mavorixafor is under study in the 4WARD Phase 3 trial in chronic neutropenia. The company also has an out-license and supply agreement with Norgine covering mavorixafor in Europe.

Revenue drivers

• XOLREMDI U.S. product sales — Net product sales were $2.4 million in Q2 2026 and $1.7 million in Q2 2025; sales are entirely U.S. WHIM syndrome prescriptions, with gross-to-net adjustments of roughly 10% in the first half of 2026.
• Norgine license and other revenue — Includes a $5.5 million regulatory milestone recognized in Q2 2026 plus $1.0 million of drug supply sales to Norgine; Q2 2026 license and other revenue contributed most of the quarter's $8.8 million total revenue.
• Full-year 2025 revenue base — Total revenue was $35.1 million in 2025, versus $2.6 million in 2024, reflecting product sales plus out-licensing revenue rather than a large recurring product base.

Recent performance

For Q2 2026, revenue was $8.8 million versus $2.0 million in Q2 2025, driven by $2.4 million of net product sales and $6.5 million of license and other revenue. Six-month 2026 revenue was $11.5 million versus $30.8 million in the first half of 2025, which had included larger one-time out-licensing amounts. Q2 2026 operating expenses were $25.2 million, with R&D of $15.1 million and G&A of $8.5 million, producing a $16.2 million net loss. 2025 full-year net loss was $79.2 million and operating cash flow was negative $85.6 million. As of June 30, 2026, cash and equivalents were $195.1 million, total liabilities $97.6 million, and shareholder equity $155.5 million.

Strategy

Management's stated highest priority is completing the 4WARD Phase 3 trial of mavorixafor in moderate and severe chronic neutropenia, targeting full enrollment of 176 patients. The company has deprioritized WHIM syndrome commercialization while maintaining U.S. patient access. It completed two 2025 financings totaling $240.3 million in gross proceeds and executed restructurings that it says cut head count by roughly 65% and will save about $13 million annualized. It plans to independently advance mavorixafor in chronic neutropenia and has transferred the EU marketing authorization to Norgine.

Risks

• Going concern and funding needs — The 10-K states that recurring losses and anticipated expenditures could raise substantial doubt about the ability to continue as a going concern, and the company says it will require substantial additional funding until profitable.
• Dependence on a single approved product — The 10-K states the company depends almost entirely on XOLREMDI for revenue, that its market size and growth are unknown, and that significant product revenue has not yet been generated.
• Clinical trial execution risk — The 4WARD trial has an increased enrollment target of 176 patients, and the company plans to meet with the FDA to revisit the trial's sample size, leaving timing and design subject to change.
• Accelerated approval and label risk — XOLREMDI's U.S. approval for WHIM syndrome is accelerated and contingent on confirmatory benefit, and the company has deprioritized WHIM commercialization while pursuing the separate chronic neutropenia indication.

Outlook

Management expects to complete enrollment in the 4WARD chronic neutropenia trial in the third quarter of 2026 and to report topline data in the second half of 2027. On the November 2025 earnings call, management said its cash runway extends to the end of 2028, which it expects to fund completion of 4WARD, a potential sNDA filing for chronic neutropenia, and a launch in that indication by the end of 2028. The company refers to a potential U.S. addressable market of 15,000 chronic neutropenia patients. The 10-Q says an FDA meeting update and enrollment completion update are expected by the end of the third quarter.