- Results support BLA submission in 2024 using the accelerated
approval pathway
- Primary endpoint of patients achieving reduction in CSF
biomarker of MPS II disease was met with statistical significance
(p value of 0.00016)
- Patients treated with RGX-121 have showed continued
improvement in neurodevelopmental skill acquisition up to four
years and discontinued intravenous enzyme therapy
- Company plans to discuss these results as part of a full
rare disease program update on its conference call today,
Wednesday, February 7, 4:30 p.m. ET
ROCKVILLE, Md., Feb. 7, 2024 /PRNewswire/ -- REGENXBIO Inc.
(Nasdaq: RGNX) today announced topline results from the Phase
I/II/III CAMPSIITE® trial of RGX-121 for the treatment
of patients up to 5 years old diagnosed with Mucopolysaccharidosis
Type II (MPS II), also known as Hunter syndrome, demonstrating that
the pivotal phase of the trial met its primary endpoint with
statistical significance.
The results were presented at the 20th Annual
WORLDSymposium™ by Paul
Harmatz, M.D., UCSF Benioff Children's Hospital and trial
investigator.
"The data from this pivotal trial supports that RGX-121 changes
the course of disease by restoring the gene missing in boys with
Hunter syndrome and has the potential to significantly improve
vital brain function for patients living with this debilitating
disease," said Kenneth T. Mills,
President and CEO of REGENXBIO. "We are excited about these results
and working quickly to complete activities to file the BLA this
year. We have shared CAMPSIITE results with FDA leadership, and
they have confirmed that, based on the totality of the evidence,
they are open to accelerated approval if supported by review of the
full data."
"There is currently no treatment to address fatal neuronopathic
CNS disease in MPS II, and I am encouraged by the topline data from
the pivotal trial of RGX-121," said Dr. Harmatz. "A one-time gene
therapy that can help these boys develop beyond the natural history
of the disease and may allow them to discontinue enzyme replacement
therapy or remain ERT-naïve represents a meaningful
breakthrough."
Data Summary
In the pivotal phase, MPS II patients
treated with RGX-121 achieved decreased cerebrospinal fluid (CSF)
levels of D2S6, a key biomarker of brain disease
activity, below maximum attenuated disease levels at 16 weeks
(p value of 0.00016). Patients receiving RGX-121 demonstrated an
86% median reduction in D2S6, approaching normal levels.
Pivotal results were consistent with data from the dose-finding
phase of CAMPSIITE. In the dose-finding phase, the majority
of patients are exceeding expectations in neurodevelopmental
function compared to natural history data up to four years. New
long-term follow-up of patients treated with RGX-121 in the
dose-finding phase also showed there was a high rate of patients
for whom trial investigators chose to discontinue standard-of-care
intravenous enzyme replacement therapy (ERT) or were allowed to
remain ERT-naïve. At the pivotal dose level, 80% of patients were
ERT-free at last time point.
As of January 3, 2024, RGX-121
continues to be well tolerated in 25 patients dosed across all
phases of the CAMPSIITE trial.
Following an RMAT meeting held with FDA at the end of 2023,
REGENXBIO continues with plans to use CSF levels of D2S6 as a
surrogate endpoint for accelerated approval and is completing
remaining activities in order to file a BLA in the second half of
2024. Based on an expected priority review, potential approval of
the planned BLA could result in receipt of a Rare Pediatric Disease
Priority Review Voucher in 2025.
Data presented is available on the "Publications" section of the
REGENXBIO website at WWW.REGENXBIO.COM.
Conference Call
As part of a full rare disease program
update, REGENXBIO will host a conference call today,
Wednesday, February 7 at 4:30 p.m. ET and will be joined by Dr. Harmatz
and Raymond Wang, M.D., Children's
Hospital of Orange County to discuss the CAMPSIITE trial pivotal
phase topline results and the expedited plan for filing a Biologics
License Application using the accelerated approval pathway in
2024.
Listeners can register for the webcast via this link. Analysts
wishing to participate in the question and answer session should
use this link. A copy of the slides being presented will be
available via the Company's investor website. Those who plan on
participating are advised to join 15 minutes prior to the start
time. A replay of the webcast will also be available via the
Company's investor website approximately two hours after the call's
conclusion.
About the CAMPSIITE® Trial
CAMPSIITE is a
Phase I/II/III multicenter, open-label trial enrolling boys with
neuronopathic MPSII, aged four months up to five years of age. The
primary endpoint of the trial is measurement of CSF GAGs. Heparan
sulfate (HS) and D2S6, a component of HS closely correlated with
severe MPS II, are GAGs that are key biomarkers of I2S enzyme
activity and are being measured in the CSF at baseline and after
administration of RGX-121. Accurate and sensitive measurements of
CSF GAGs, such as 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 an investigational, one-time
gene therapy designed to deliver the iduronate-2-sulfatase gene
(IDS) that encodes the iduronate-2-sulfatase enzyme (I2S) using the
NAV® AAV9 vector. RGX-121 expressed protein is
structurally identical to normal I2S. RGX-121 is administered
directly to the central nervous system (CNS) using intracisternal
or intracerebroventricular delivery. 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 heparan sulfate (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.
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 and AAV9.
REGENXBIO and its third-party NAV Technology Platform Licensees are
applying the NAV Technology Platform in the development of a broad
pipeline of candidates, including late-stage and commercial
programs, in multiple therapeutic areas. REGENXBIO is committed to
a "5x'25" strategy to progress five AAV Therapeutics from our
internal pipeline and licensed programs into pivotal-stage or
commercial products by 2025.
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, 2022, 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.
Contacts:
Dana Cormack
Corporate Communications
dcormack@regenxbio.com
Investors:
Chris Brinzey
ICR Westwicke
339-970-2843
chris.brinzey@westwicke.com
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