X4 Pharmaceuticals and The Leukemia & Lymphoma Society Announce Collaboration to Advance Development of Mavorixafor in Waldenström’s Macroglobulinemia

May 15, 2019 Off By BusinessWire

Mavorixafor selected for LLS’s Therapy Acceleration Program®
(TAP)

CAMBRIDGE, Mass. & RYE BROOK, N.Y.–(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, and The Leukemia &
Lymphoma Society (LLS) today announced a collaboration to accelerate the
development of X4’s lead product candidate, mavorixafor (X4P-001) for
the treatment of Waldenström’s macroglobulinemia (WM), a rare form of
non-Hodgkin lymphoma.

Mavorixafor was selected for LLS’s Therapy Acceleration Program®
(TAP), a strategic initiative where LLS builds business alliances and
collaborations with biotechnology companies and academic researchers to
speed the development of new therapies for blood cancers. Under the
collaboration, X4 will conduct a multi-national Phase 1/2 clinical trial
to evaluate the safety and assess the preliminary anti-tumor activity of
mavorixafor in combination with ibrutinib in WM patients. The trial is
planned to commence this year. Lee Greenberger, Ph.D., chief scientific
officer of LLS, will also serve as a member of an advisory board to X4,
providing important strategy and partnership guidance throughout the
trial.

“LLS’s selection of mavorixafor for TAP collaboration and investment
reinforces its potential as a novel therapy for Waldenström’s
macroglobulinemia. Approximately 30 to 40 percent of WM patients have a
CXCR4 mutation, and a number of these patients do not respond well to
current therapies,” said Paula Ragan, Ph.D., president and chief
executive officer of X4 Pharmaceuticals. “We look forward to working
closely with Dr. Greenberger and the LLS TAP team to gain valuable data
and insights throughout the upcoming clinical trial as we work to bring
a new therapeutic option to patients with this rare form of cancer.”

Mavorixafor is a first-in-class, oral, small molecule allosteric
antagonist of the chemokine receptor CXCR4 and is designed to address
certain rare primary immunodeficiency diseases and certain cancers,
including lymphomas, in which genetic mutations in CXCR4 create abnormal
trafficking of white blood cells and play a role in disease process.

“Through TAP, LLS is committed to advancing the development of promising
investigational therapies that we believe have potential to improve
standards of care for patients, especially in disease areas with high
unmet medical need, such as Waldenström’s macroglobulinemia,” said Dr.
Greenberger. “Mavorixafor has demonstrated early promise in other
disease areas with CXCR4 mutations, including solid tumors, and its
potential application among CXCR4-mutant WM patients makes it an
excellent fit and an important asset within our program as we work with
innovative companies like X4 to uncover and develop cutting-edge
therapies for patients with blood cancers.”

About Waldenström’s Macroglobulinemia
Waldenström’s
macroglobulinemia (WM) is a rare form of non-Hodgkin lymphoma and B-cell
lymphoproliferative disorder. According to the American Cancer Society,
approximately three per one million people are diagnosed each year,
including 1,400 new cases in the United States annually. Recent
advancements in whole-genome sequencing have identified genetic
mutations in the disease similar to WHIM syndrome, a rare congenital
primary immunodeficiency characterized by warts, hypogammaglobulinemia,
infection and myelokathexis. Approximately 30 to 40 percent of WM cases
express mutations in the CXCR4 gene in the cancer cells. In WM, somatic
mutations of CXCR4 are associated with active tumor cells and possible
drug resistance, including resistance to anti-CD20 monoclonal antibodies
and Burton tyrosine kinase (BTK) inhibitors, such as ibrutinib, the
current standard of care. WM patients with this somatic mutation have a
dramatically reduced median progression-free survival, or mPFS, of
approximately two years, whereas patients without the mutation have a
mPFS of well over five years.

About the Therapy Acceleration Program®
The
Leukemia & Lymphoma Society’s Therapy Acceleration Program®
(TAP) identifies and funds innovative projects related to therapies,
supportive care or diagnostics that have the potential to change the
standard of care for patients with blood cancer, especially in areas of
high unmet medical need. TAP funding assists both clinical investigators
and companies in gaining critical clinical proof of concept data that
better enables them to obtain the resources they need or a partner to
complete the testing, registration and marketing of new treatments,
supportive care and diagnostics for leukemia, lymphoma and myeloma. TAP
funding is different from the traditional grant at LLS. The TAP review
process is separate from the grant process and LLS’s TAP staff play an
active advisory role and closely monitor each approved project. To learn
more about how TAP works, please click here.

About X4 Pharmaceuticals
X4 Pharmaceuticals is developing
novel therapeutics designed to improve immune cell trafficking to treat
rare diseases, including primary immunodeficiencies and certain cancers.
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), is expected to commence 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.

Forward-Looking Statements
This press release contains
forward-looking statements within the meaning of the Private Securities
Litigation Reform Act of 1995, as amended. The words “may,” “will,”
“could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,”
“believe,” “estimate,” “predict,” “project,” “potential,” “continue,”
“target” and similar expressions are intended to identify
forward-looking statements, although not all forward-looking statements
contain these identifying words. Forward-looking statements include
statements regarding 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
and the Phase 1/2 clinical trial of mavorixafor for the treatment of
patients with WM, 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. These statements are subject to
various risks and uncertainties, actual results could differ materially
from those projected and X4 cautions investors not to place undue
reliance on the forward-looking statements in this press release. These
risks and uncertainties include, without limitation, 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 the collaboration
with LLS will not be successful, and the risk that costs required to
develop mavorixafor or other product candidates or to expand our
operations will be higher than anticipated. Any forward-looking
statements in this press release are based on management’s current
expectations and beliefs and are subject to a number of risks,
uncertainties and important factors that may cause actual events or
results to differ materially from those expressed or implied by any
forward-looking statements contained in this press release, including,
without limitation, the risks and uncertainties described in the section
entitled “Risk Factors” in X4’s most recent Annual Report on Form 10-K
filed with the Securities and Exchange Commission (SEC), as updated by
X4’s Current Report on Form 8-K filed with the SEC on April 11, 2019,
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 subsequently occurring events or circumstances.

Contacts

Investors:
Stephanie Carrington
Westwicke, an ICR
company
646-277-1282
[email protected]

Media:
Darcie Robinson
Westwicke, an ICR company
203-919-7905
[email protected]

Andrea Greif
The Leukemia & Lymphoma Society
914-821-8958
[email protected]