ROCKVILLE, Md., July 8, 2020 /PRNewswire/ -- REGENXBIO Inc.
(Nasdaq: RGNX), a leading clinical-stage biotechnology company
seeking to improve lives through the curative potential of gene
therapy based on its proprietary NAV® Technology
Platform, today announced that it has completed dosing of three
patients in Cohort 2 of the Company's Phase I/II study of RGX-121
for the treatment of Mucopolysaccharidosis Type II (MPS II) and
reported encouraging data under a single-patient
investigator-initiated Investigational New Drug (IND) application
for RGX-111 for the treatment of Mucopolysaccharidosis Type I (MPS
I) conducted at CHOC Children's.
"We are pleased to have completed the dosing of three patients
with MPS II at the second dose level of our RGX-121 Phase I/II
study, which included involvement from new leading centers at UCSF
Benioff Children's Hospital Oakland and Hospital de Clínicas de
Porto Alegre in Brazil. We expect to provide an additional
interim data update from the RGX-121 program later this year," said
Steve Pakola, M.D., Chief Medical
Officer of REGENXBIO. "Further, we are encouraged by the initial
data from the first patient dosed with RGX-111, and we look forward
to advancing our RGX-111 Phase I/II study."
Enrollment in Cohort 2 of the Phase I/II study of RGX-121 is now
complete, with three patients with MPS II dosed intracisternally
with 6.5x1010 genome copies per gram (GC/g) of brain
mass. As of June 24, 2020, RGX-121 is
reported to be well-tolerated in patients across two dose levels,
with no drug-related serious adverse events (SAEs). Additional data
from both cohorts in this study and a program update will be
available in the second half of 2020.
Under a single-patient investigator-initiated IND for RGX-111,
Raymond Wang, M.D., a biochemical
genetics specialist at CHOC Children's, dosed a patient with severe
MPS I intracisternally with 1x1010 GC/g of brain mass at
the age of 21 months. MPS I is caused by a deficiency of the enzyme
α-l-iduronidase (IDUA) and subsequent accumulation of heparan
sulfate (HS) within the central nervous system (CNS). High levels
of HS in the CSF closely correlate with neurocognitive decline and
are a key biomarker of enzyme activity. As of June 9, 2020, RGX-111 is reported to be
well-tolerated in this patient, with no drug-related SAEs.
The IDUA enzyme activity in the patient's cerebrospinal fluid
(CSF) was below the limit of quantification prior to the
administration of RGX-111. An increase in IDUA enzyme activity was
detected at Week 12, the latest timepoint available following
administration of RGX-111. High levels of HS in the CSF were
measured in this patient at baseline, and initial data demonstrated
sustained decreases in total HS in the CSF over time, with a 50%
reduction from baseline at Week 12 and a 45% reduction from
baseline at Week 33, the latest timepoint available.
Neurocognitive development in untreated MPS I patients is
characterized by a plateau followed by a significant decline
between 1 and 3 years of age. At Week 32 post-administration of
RGX-111, neurocognitive evaluations indicated that the patient, who
was then 29 months of age, continued to acquire cognitive
developmental skills at a normal rate.
Dr. Wang commented, "I thank the research team at CHOC
Children's and the child's family for working together to make this
study possible. I am extremely encouraged by the clinical and
biochemical indicators eight months post-treatment in this first
person with MPS I dosed with RGX-111. The promising signals of IDUA
expression and reduced HS levels in CSF, and an indication of
ongoing neurocognitive development, provide additional evidence of
the potential of RGX-111 for individuals who have MPS I."
Recruitment, screening and additional site activations are
ongoing in a Phase I/II clinical trial of RGX–111. REGENXBIO
expects to provide a program update in the second half of 2020.
Additional information about REGENXBIO's Phase I study of RGX-111
may be found at ClinicalTrials.gov, using Identifier
NCT: NCT03580083.
About RGX-111
RGX-111 is a product candidate for the treatment of
Mucopolysaccharidosis Type I (MPS I), also known as Hurler
syndrome. RGX-111 is designed to use the AAV9 vector to deliver the
α-l-iduronidase (IDUA) gene. Delivery of the enzyme that is
deficient within cells in the central nervous system (CNS) could
provide a permanent source of secreted IDUA beyond the blood-brain
barrier, allowing for long-term cross-correction of cells
throughout the CNS. This strategy could also provide rapid IDUA
delivery to the brain, potentially preventing the progression of
cognitive deficits that otherwise occurs in MPS I patients. RGX-111
has received orphan drug product, rare pediatric disease and Fast
Track designations from the U.S. Food and Drug Administration.
About the Phase I/II Clinical Trial of RGX-111
RGX-111 is being evaluated in a Phase I/II, first-in-human,
multi-center, open-label, dose escalation study in patients with
Mucopolysaccharidosis Type I (MPS I). The Phase I/II trial is
designed to evaluate the safety of RGX-111 and secondary endpoints
include the effect of RGX–111 on biomarkers of α-l-iduronidase
(IDUA) enzyme activity in the CSF, serum and urine, neurocognitive
development and other outcome measures.
About Mucopolysaccharidosis Type I (MPS I)
MPS I is a rare autosomal recessive genetic disease caused by
deficiency of IDUA, an enzyme required for the breakdown of the
polysaccharides in lysosomes. These polysaccharides, called
glycosaminoglycans (GAGs), accumulate in tissues of MPS I patients,
resulting in characteristic storage lesions and diverse clinical
signs and symptoms including in the central nervous system (CNS),
which can include excessive accumulation of fluid in the brain,
spinal cord compression, and cognitive impairment. MPS I is
estimated to occur in 1 in 100,000 births. Current disease
modifying therapies for MPS I include hematopoietic stem cell
transplant (HSCT) and enzyme replacement therapy with a recombinant
form of human IDUA administered intravenously. However, intravenous
enzyme therapy does not treat the CNS manifestations of MPS I, and
HSCT can be associated with clinically significant morbidity and
mortality.
About RGX-121
RGX-121 is a product candidate for the treatment of
Mucopolysaccharidosis Type II (MPS II), also known as Hunter
syndrome. RGX-121 is designed to use the AAV9 vector to deliver the
human iduronate-2-sulfatase (IDS) gene which encodes the
iduronate-2-sulfatase (I2S) enzyme to the central nervous system
(CNS). Delivery of the IDS gene within cells in the CNS could
provide a permanent source of secreted I2S beyond the blood-brain
barrier, allowing for long-term cross correction of cells
throughout the CNS. RGX-121 has received orphan drug product, rare
pediatric disease and Fast Track designations from the U.S. Food
and Drug Administration.
About the Phase I/II Clinical Trial of RGX-121
RGX–121 is being evaluated in a Phase I/II, multi-center,
open-label, multiple-cohort, dose–escalation study in patients with
Mucopolysaccharidosis Type II (MPS II) in the United States and Brazil. The Phase I/II trial is designed to
evaluate the safety of RGX-121 in up to 6 patients less than five
years of age who have or are at high risk of developing
neurocognitive effects. In addition, the study will evaluate the
effect of RGX-121 on biomarkers of iduronate-2-sulfatase (I2S)
enzyme activity as well as neurocognitive deficits and other
clinical measures.
About Mucopolysaccharidosis Type II (MPS II)
MPS II is a rare, X-linked recessive disease caused by a
deficiency in the lysosomal enzyme iduronate-2-sulfatase (I2S)
leading to an accumulation of glycosaminoglycans, including heparan
sulfate (HS) in tissues which ultimately results in cell, tissue,
and organ dysfunction. In severe forms of the disease, early
developmental milestones may be met, but developmental delay is
readily apparent by 18 to 24 months. Specific treatment to address
the neurological manifestations of MPS II and prevent or stabilize
cognitive decline remains a significant unmet medical need. Key
biomarkers of I2S enzymatic activity in MPS II patients include its
substrate heparan sulfate (HS), which has been shown to correlate
with neurocognitive manifestations of the disorder.
About REGENXBIO Inc.
REGENXBIO is a leading clinical-stage biotechnology company
seeking to improve lives through the curative potential of gene
therapy. REGENXBIO's NAV® Technology Platform, a proprietary
adeno-associated virus (AAV) gene delivery platform, consists of
exclusive rights to more than 100 novel AAV vectors, including
AAV7, AAV8, AAV9 and AAVrh10. REGENXBIO and its third-party NAV
Technology Platform Licensees are applying the NAV Technology
Platform in the development of a broad pipeline of candidates in
multiple therapeutic areas.
Forward-Looking Statements
This press release includes "forward-looking statements," within
the meaning of Section 27A of the Securities Act of 1933, as
amended, and Section 21E of the Securities Exchange Act of 1934, as
amended. These statements express a belief, expectation or
intention and are generally accompanied by words that convey
projected future events or outcomes such as "believe," "may,"
"will," "estimate," "continue," "anticipate," "design," "intend,"
"expect," "could," "plan," "potential," "predict," "seek,"
"should," "would" or by variations of such words or by similar
expressions. The forward-looking statements include statements
relating to, among other things, REGENXBIO's future operations and
clinical trials. REGENXBIO has based these forward-looking
statements on its current expectations and assumptions and analyses
made by REGENXBIO in light of its experience and its perception of
historical trends, current conditions and expected future
developments, as well as other factors REGENXBIO believes are
appropriate under the circumstances. However, whether actual
results and developments will conform with REGENXBIO's expectations
and predictions is subject to a number of risks and uncertainties,
including the timing of enrollment, commencement and completion and
the success of clinical trials conducted by REGENXBIO, its
licensees and its partners, the timing of commencement and
completion and the success of preclinical studies conducted by
REGENXBIO and its development partners, the timely development and
launch of new products, the ability to obtain and maintain
regulatory approval of product candidates, the ability to obtain
and maintain intellectual property protection for product
candidates and technology, trends and challenges in the business
and markets in which REGENXBIO operates, the size and growth of
potential markets for product candidates and the ability to serve
those markets, the rate and degree of acceptance of product
candidates, the impact of the COVID-19 pandemic or similar public
health crises on REGENXBIO's business, and other factors, many of
which are beyond the control of REGENXBIO. Refer to the "Risk
Factors" and "Management's Discussion and Analysis of Financial
Condition and Results of Operations" sections of REGENXBIO's Annual
Report on Form 10-K for the year ended December 31, 2019, and comparable "risk factors"
sections of REGENXBIO's Quarterly Reports on Form 10-Q and other
filings, which have been filed with the U.S. Securities and
Exchange Commission (SEC) and are available on the SEC's website at
www.sec.gov. All of the forward-looking statements made in this
press release are expressly qualified by the cautionary statements
contained or referred to herein. The actual results or developments
anticipated may not be realized or, even if substantially realized,
they may not have the expected consequences to or effects on
REGENXBIO or its businesses or operations. Such statements are not
guarantees of future performance and actual results or developments
may differ materially from those projected in the forward-looking
statements. Readers are cautioned not to rely too heavily on the
forward-looking statements contained in this press release. These
forward-looking statements speak only as of the date of this press
release. REGENXBIO does not undertake any obligation, and
specifically declines any obligation, to update or revise any
forward-looking statements, whether as a result of new information,
future events or otherwise.
Contacts:
Tricia
Truehart
Investor Relations and Corporate Communications
347-926-7709
ttruehart@regenxbio.com
Investors:
Heather Savelle, 212-600-1902
heather@argotpartners.com
Media:
David Rosen, 212-600-1902
david.rosen@argotpartners.com
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