X4 Pharmaceuticals Appoints Murray W. Stewart, M.D. to Board of Directors

April 2, 2019 Off By BusinessWire

CAMBRIDGE, Mass.–(BUSINESS WIRE)–X4 Pharmaceuticals, Inc. (Nasdaq: XFOR), a clinical-stage
biopharmaceutical company focused on the development of novel
therapeutics for the treatment of rare diseases, today announced the
appointment of Murray Stewart, M.D., as an independent member of the X4
Board of Directors.

“We’re very pleased to welcome Dr. Stewart to the X4 Board,” said Paula
Ragan, Ph.D., President and Chief Executive Officer of X4
Pharmaceuticals. “His extensive global industry expertise, which spans
research, clinical development, medical affairs, and regulatory
strategy, combined with his strong biopharmaceutical leadership skills
will be a tremendous asset as we transition to Phase 3 development with
our lead product candidate, mavorixafor, and work to develop and
commercialize innovative therapies for the treatment of rare diseases.”

“X4 is at a critical juncture of growth and I am excited to join such a
driven and dynamic team of leaders. As the company advances its pipeline
of therapies for patients with rare genetic diseases and rare cancers,
targeting the CXCR4 pathway, I look forward to contributing my
experience and insights to help create long-term growth for a
sustainable global rare disease business,” commented Dr. Stewart.

Dr. Stewart currently serves as Chief Medical Officer of Rhythm
Pharmaceuticals, Inc., a biopharmaceutical company focused on developing
and commercializing therapies for the treatment of rare genetic
disorders of obesity. Before joining Rhythm Pharmaceuticals in 2018, Dr.
Stewart was Head of R&D for Novelion, where he oversaw global medical
affairs for Juxtapid^® and Myalept^®, two marketed
products for rare metabolic diseases. Prior to that, Dr. Stewart was
Chief Medical Officer at GlaxoSmithKline (GSK), with global
responsibility for patient well-being across the vaccine,
pharmaceutical, and consumer business units. During his 18-year career
at GSK, Dr. Stewart held multiple research and development leadership
roles, including Chief Medical Officer for the pharmaceutical business,
Clinical Head of the Biopharma Unit, and Therapy Area Head for metabolic
and cardiovascular diseases. Prior to his tenure with GSK, he worked as
a consultant physician and honorary senior lecturer at the Diabetes
Center in Newcastle upon Tyne in the U.K. Dr. Stewart is an M.D. from
Southampton Medical School and is a Fellow of the Royal College of
Physicians.

About X4 Pharmaceuticals

X4 Pharmaceuticals is developing novel therapeutics designed to improve
immune cell trafficking to treat rare diseases, including primary
immunodeficiencies and cancer. X4’s oral small molecule drug candidates
antagonize the CXCR4 pathway, which plays a central role in immune
surveillance. X4’s most advanced product candidate, mavorixafor
(X4P-001), will be commencing a global Phase 3 pivotal trial in patients
with WHIM syndrome, a rare genetic, primary immunodeficiency disease, in
the second quarter of 2019 and is currently also under investigation in
a Phase 2a clinical trial in clear cell renal cell carcinoma. X4 was
founded and is led by a team with extensive product development and
commercialization expertise, including several former members of the
Genzyme leadership team, and is located in Cambridge, Massachusetts. For
more information, visit www.x4pharma.com.

Forward-Looking Statements

This press release contains forward-looking statements that involve
substantial risks and uncertainties. All statements, other than
statement of historical facts, included in this press release regarding
our strategy, future operations, and plans are forward-looking
statements. Examples of such statements include, but are not limited to,
statements relating to plans for, or progress, scope, cost, duration or
results or timing for the initiation, completion or availability of
results of development of mavorixafor (X4P-001) or any of our other
product candidates or programs, including regarding the Phase 3 clinical
trial of mavorixafor for the treatment of patients with WHIM syndrome,
the target indication(s) for development, the size, design, population,
location, conduct, objective, duration or endpoints of any clinical
trial, or the timing for initiation or completion of or reporting of
results from any clinical trial, the potential benefits of mavorixafor,
or any other product candidate or program or the commercial opportunity
in any target indication; or the potential benefits of orphan drug
designation. Actual results or events could differ materially from the
plans, intentions, expectations and projections disclosed in the
forward-looking statements. Various important factors could cause actual
results or events to differ materially from the forward-looking
statements that X4 makes, including, but not limited to, the risk that
trials and studies may be delayed and may not have satisfactory
outcomes, potential adverse effects arising from the testing or use of
mavorixafor or other product candidates, the risk that costs required to
develop mavorixafor or other product candidates or to expand our
operations will be higher than anticipated and other risks described in
the “Risk Factors” section of the Registration Statement on Form S-4
filed by X4 Pharmaceuticals with the SEC and declared effective by the
SEC on February 14, 2019. X4 does not assume any obligation to update
any forward-looking statements, except as required by law.