- Data from pivotal dose level demonstrates long-term,
sustained reductions in CSF levels of HS D2S6, a key biomarker of
brain disease in MPS II
- 80% of patients who
received the pivotal dose discontinued intravenous enzyme
replacement therapy or remained treatment-naïve
-
Submission of a rolling BLA using the accelerated approval
pathway on track for Q3 2024
ROCKVILLE, Md., Sept. 3,
2024 /PRNewswire/ -- REGENXBIO Inc. (Nasdaq: RGNX)
today announced positive results from the Phase I/II/III
CAMPSIITE® trial of RGX-121 for the treatment of
patients with Mucopolysaccharidosis Type II (MPS II), also known as
Hunter syndrome. The results were presented at the Society for the
Study of Inborn Errors of Metabolism (SSIEM) Annual Symposium
2024.
The totality of evidence from the CAMPSIITE trial continues to
support RGX-121 as the potential first gene therapy and one-time
treatment for MPS II. In the United
States, RGX-121 is also on track to be the first treatment
that addresses the neurocognitive decline associated with MPS II,
with the potential to be the first-line treatment for patients with
neuronopathic disease.
"As we quickly approach the BLA filing for RGX-121, we are very
pleased with the data presented at SSIEM demonstrating encouraging
evidence of systemic activity and long-term reductions of CSF
D2S6," said Steve Pakola, M.D.,
Chief Medical Officer of REGENXBIO. "The data continue to support
that by restoring the gene missing in boys with Hunter syndrome,
RGX-121 changes the course of disease and has the potential to
significantly improve both vital brain function and the systemic
manifestations of this devastating disease."
Data Summary
In new, long-term data from the
Phase I/II/III CAMPSIITE® trial, patients receiving
RGX-121 at the pivotal dose level demonstrated an 85% median
reduction of cerebrospinal fluid (CSF) levels of heparan sulfate
(HS) D2S6, a key biomarker of brain disease
activity, approaching normal levels and sustained for up to
two years. Topline results presented earlier this year from the
CAMPSIITE trial demonstrated that the pivotal phase of the trial
met its primary endpoint with statistical significance. Pivotal
results were consistent with data from the dose-finding phase of
CAMPSIITE, in which the majority of patients were shown to be
exceeding expectations in neurodevelopmental function compared to
natural history data up to four years.
In the dose-finding part of the trial, investigators chose to
discontinue standard-of-care intravenous enzyme replacement therapy
(ERT) or to remain ERT-naïve for a majority of patients. At the
pivotal dose level (dose level 3), 80% of patients were ERT-free at
last time point, up to more than 18 months post-dosing. At dose
level 2, 71% of patients were ERT-free at last time point, up to
almost three years.
As of January 5, 2024, RGX-121
continues to be well tolerated in 25 patients dosed across all
phases of the CAMPSIITE trial.
"A potential one-time treatment that can allow these boys
to exceed the natural history of this disease in their
neurocognitive development, as well as the ability to remain off
enzyme replacement therapy for multiple years represents a
meaningful option for patients and their families," said Roberto
Giugliani, M.D., Ph.D., Professor, Department of Genetics, UFRGS,
Medical Genetics Service, HCPA, Porto
Alegre, Brazil. "I continue to be very encouraged by the
data supporting RGX-121 and look forward to the seeing this program
advance towards potential approval for this community."
REGENXBIO is on track to initiate a rolling Biologics License
Application (BLA) submission using the accelerated approval pathway
in the third quarter of 2024 using CSF D2S6 as a surrogate endpoint
reasonable likely to predict clinical benefit. Approval of the
planned BLA could result in receipt of a Priority Review Voucher in
2025.
Data presented is available on the "Publications" section of the
REGENXBIO website at WWW.REGENXBIO.COM.
About the CAMPSIITE® Trial
CAMPSIITE is a
Phase I/II/III multicenter, open-label trial for boys aged four
months up to five years with neuronopathic MPS II. The
primary endpoint of the trial is measurement of CSF GAGs. Accurate
and sensitive measurements of CSF GAGs, such as HS D2S6, have the
potential to be considered a surrogate endpoint that is reasonably
likely to predict clinical benefit in MPS II disease under the
accelerated approval pathway, as buildup of GAGs in the CSF of MPS
II patients correlates with clinical manifestations including
neurodevelopmental deficits.
The pivotal program is using commercial-scale cGMP material from
REGENXBIO's proprietary, high-yielding suspension-based
manufacturing process, named NAVXpress™. In addition to measuring
GAGs in the CSF, the trial will continue to collect
neurodevelopmental data and caregiver-reported outcomes.
About RGX-121
RGX-121 is a potential one-time AAV
therapeutic for the treatment of boys with MPS II. RGX-121
expressed protein is structurally identical to normal I2S. RGX-21
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, Fast Track and Regenerative Medicine Advanced Therapy
designations from the U.S. Food and Drug Administration and
advanced therapy medicinal products (ATMP) classification from the
European Medicines Agency.
About Mucopolysaccharidosis Type II (MPS II)
MPS II,
or Hunter Syndrome, 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 (GAGs), including
heparan sulfate (HS) in tissues which ultimately results in cell,
tissue, and organ dysfunction, including in the central nervous
system (CNS). MPS II is estimated to occur in 1 in 100,000 to
170,000 births. 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 remains a significant unmet medical need.
Key biomarkers of I2S enzymatic activity in MPS II patients include
its substrate HS D2S6, 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. Since its founding
in 2009, REGENXBIO has pioneered the development of AAV
Therapeutics, an innovative class of gene therapy medicines.
REGENXBIO is advancing a pipeline of AAV Therapeutics for retinal
and rare diseases, including ABBV-RGX-314 for the treatment of wet
AMD and diabetic retinopathy, being developed in collaboration with
AbbVie, RGX-202 for the treatment of Duchenne and RGX-121 for the
treatment of MPS II. Thousands of patients have been treated with
REGENXBIO's AAV Therapeutic platform, including Novartis' ZOLGENSMA
for children with spinal muscular atrophy. Designed to be one-time
treatments, AAV Therapeutics have the potential to change the way
healthcare is delivered for millions of people. For more
information, please visit www.regenxbio.com.
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," "assume," "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, 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, 2023, 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. Except as required by law,
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.
Zolgensma® is a registered trademark of Novartis Gene
Therapies. All other trademarks referenced herein are registered
trademarks of REGENXBIO.
Contacts:
Dana Cormack
Corporate Communications
dcormack@regenxbio.com
Investors:
Chris Brinzey
ICR Westwicke
339-970-2843
chris.brinzey@westwicke.com
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