X4 Pharmaceuticals to Host Virtual Investor Event on June 27, 2024 to Review New Mavorixafor Clinical Data from Ongoing Phase 2 Trial in Chronic Neutropenia

Webcast to include interim hematological results from at least 15 trial participants and feature experts in the treatment of chronic neutropenia

BOSTON, May 29, 2024 (GLOBE NEWSWIRE) — X4 Pharmaceuticals (Nasdaq: XFOR), a company driven to improve the lives of people with rare diseases of the immune system, today announced that it will host a virtual investor event on Thursday, June 27, 2024 at 8:00 am ET. To register for the event, click here.

The event will focus on new interim results from an ongoing Phase 2 clinical trial exploring the use of mavorixafor as a once-daily oral treatment in patients with chronic neutropenia (CN). The data to be presented will include hematological results from at least 15 study participants treated with either mavorixafor monotherapy or mavorixafor in combination with stable doses of injectable granulocyte colony-stimulating factor (G-CSF). Physician expert commentary on the clinical results and the high unmet need in CN will also be included as part of the event.

As previously communicated, the company plans to initiate a global, pivotal Phase 3 clinical trial in the current quarter that aims to evaluate the efficacy, safety, and tolerability of oral once-daily mavorixafor (with or without G-CSF) in people with congenital or acquired primary autoimmune and idiopathic chronic neutropenia who are experiencing recurrent and/or serious infections.

A live question and answer session will follow the formal presentation.

About Chronic Neutropenia and Mavorixafor
Chronic neutropenic disorders are rare blood conditions lasting more than three months, persistently or intermittently, and characterized by increased risk of infections and reduced quality of life due to persistent, abnormally low levels of neutrophils circulating in the blood. Neutrophils are retained in the bone marrow by the CXCR4/CXCL12 axis, creating a reserve of cells; downregulation of the CXCR4 receptor by G-CSF or inhibition of the receptor by mavorixafor, an orally active CXCR4 antagonist, has been shown to mobilize neutrophils from the bone marrow into the peripheral blood.

About X4 Pharmaceuticals
X4 is delivering progress for patients by developing and commercializing innovative therapies for those with rare diseases of the immune system and significant unmet needs. Leveraging our expertise in CXCR4 and immune system biology, we have successfully developed mavorixafor, which has received U.S. approval as XOLREMDI™ (mavorixafor) capsules in its first indication. We are also evaluating the use of mavorixafor in additional potential indications. X4 corporate headquarters are in Boston, Massachusetts and our research center of excellence is in Vienna, Austria. For more information, please visit our website at www.x4pharma.com.

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 the clinical progress of X4’s pipeline development programs including its interim clinical results from its ongoing Phase 2 clinical trial; uncertainties inherent in the initiation and completion of clinical trials and clinical development; the risk that trials and studies may not have satisfactory outcomes; the risk that the outcomes of preclinical studies or earlier clinical trials will not be predictive of later clinical trial results; the risk that initial or interim results from a clinical trial may not be predictive of the final results of the trial or the results of future trials; and the potential adverse effects arising from the testing or use of mavorixafor or other product candidates. 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 the risks that: X4 may not be able to obtain regulatory approval for, or successfully commercialize, mavorixafor or any other product candidate for other chronic neutropenic disorders or any other potential indication; the expected availability, content, and timing of clinical data from X4’s ongoing clinical trials of mavorixafor may be delayed or unavailable; the clinical trial design and rate of enrollment for clinical trials as well as potential therapeutic benefits, including the current design for of a potential Phase 3 clinical trial evaluating mavorixafor in certain chronic neutropenic disorders and its expected initiation in the first half of 2024 may not enable successful completion of the trial(s); uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development; 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; initial or interim results from a clinical trial may not be predictive of the final results of the trial or the results of future trials; and the potential adverse safety effects arising from the testing or use of mavorixafor or other product candidates 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.

Company Contact:
José Juves
Head of Corporate & Patient Affairs
jose.juves@x4pharma.com

Investor Contact:
Daniel Ferry
Managing Director, LifeSci Advisors
daniel@lifesciadvisors.com
(617) 430-7576