X4 Pharmaceuticals Inc

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of applicable securities laws, including the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by the words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target,” or other similar terms or expressions that concern X4's expectations, strategy, plans, or intentions. Forward-looking statements include, without limitation, implied or express statements regarding X4’s expected cash runway; X4’s commercialization plans and ongoing efforts with respect to XOLREMDI and the expected timing thereof; and other statements regarding X4’s future operations, financial performance, financial position, prospects, objectives and other future events; the potential therapeutic benefit of mavorixafor; the initiation, timing, progress, and results of our current and future studies and clinical trials, including the Phase 2 clinical trial in chronic neutropenia and the Phase 3 4WARD clinical trial and related preparatory work and the period during which the results of the trials will become available; and the mission and goals for our business. Any forward-looking statements in this press release are based on management's current expectations and beliefs. These forward-looking statements are neither promises nor guarantees of future performance, and are subject to a variety of risks and uncertainties, many of which are beyond X4’s control, which could cause actual results to differ materially from those contemplated in these forward-looking statements, including, without limitation, the risks that: unanticipated costs and expenses may be greater than anticipated; X4’s cash and cash equivalents may not be sufficient to support its operating plan for as long as anticipated; delays, interruptions or failures in the manufacture and supply of X4’s products; X4’s ability to obtain additional funding to support its clinical development and commercial programs; we may encounter adverse events for mavorixafor at any stage that negatively impact development and/or commercialization; the expected availability, content, and timing of clinical data from our ongoing clinical trials of mavorixafor may be delayed or unavailable, including clinical results from our ongoing Phase 2 clinical trial and the announced Phase 3 4WARD trial; the trials and studies may not have satisfactory outcomes; the outcomes of preclinical studies or earlier clinical trials will not be predictive of later clinical trial results; the design and rate of enrollment for clinical trials, including the current design of our Phase 3 clinical trial evaluating mavorixafor in certain chronic neutropenic disorders may not enable successful completion of the trial(s); we may be unable to obtain and maintain regulatory approvals; uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development; there will be changes in expected or existing competition; there will be changes in the regulatory environment; our business may be adversely affected and our costs may increase if any of our key collaborators fails to perform its obligations or terminates our collaboration; the internal and external costs required for our ongoing and planned activities, and the resulting impact on expense and use of cash, may be higher than expected which may cause us to use cash more quickly than we expect or to change or curtail some of our plans or both; and other risks and uncertainties, including those described in the section entitled

“Risk Factors” in X4’s Annual Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on May 7, 2024, and in other filings X4 makes with the SEC from time to time. X4 undertakes no obligation to update the information contained in this press release to reflect new events or circumstances, except as required by law.

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