- Company to begin enrollment of patients aged 1-3
years
- Expects data from younger cohort to be part of pivotal plans
and BLA filing for broad label
- End-of-Phase II meeting with FDA scheduled for late July to
finalize pivotal program design
- Based on recent commercial landscape, confirmed accelerated
approval pathway remains available given ongoing unmet need and
RGX-202 differentiated design
- Remains on track to initiate pivotal trial in late Q3 to
early Q4 2024
- The next potential therapy to become available for Duchenne
patients
ROCKVILLE, Md.,
June 24,
2024 /PRNewswire/ -- REGENXBIO Inc. (Nasdaq: RGNX)
today announced it initiated enrollment in a new cohort of patients
ages 1-3 in its Phase I/II AFFINITY DUCHENNE® trial to
evaluate the safety and efficacy of RGX-202 in boys with Duchenne
muscular dystrophy (Duchenne).
RGX-202 is an investigational one-time AAV Therapeutic targeted
to deliver a novel microdystrophin, representing the next wave of
innovative design in Duchenne gene therapy. RGX-202 is the only
gene therapy approved or in development for Duchenne that
incorporates the C-Terminal domain, making the RGX-202 transgene
the closest to the naturally occurring dystrophin gene.
With this announcement, REGENXBIO is enrolling ambulatory boys
with Duchenne aged 1 to 11 in the AFFINITY DUCHENNE trial. The new
cohort is expected to enroll up to five patients aged 1-3 to
receive RGX-202 at the pivotal dose level
(2x1014 genome copies (GC)/kg body weight).
Additionally, REGENXBIO has confirmed an end-of-Phase II (EOP2)
meeting is scheduled with the FDA at the end of July. This meeting
is expected to finalize the AFFINITY DUCHENNE pivotal trial design,
with the goal of continuing to expedite the development of RGX-202.
The Company anticipates that all patients enrolled at dose level 2
(n=12) will be included in its pivotal trial data set. The Company
plans to use RGX-202 microdystrophin expression as a surrogate
endpoint to support a Biologics License Application (BLA)
submission using the accelerated approval pathway with the
potential to receive a broad label. REGENXBIO has recently
confirmed with the FDA that the pathway can be used given the
ongoing high unmet need for differentiated treatment options in the
Duchenne community. RGX-202 is the most advanced gene therapy
enrolling in active clinical trials and is anticipated to be the
next gene therapy in a BLA filing for Duchenne.
"We believe RGX-202 has unique, differentiating features that
support its potential to be a best-in-class product and we are
pleased to expand its clinical development to reach a wider range
of boys with Duchenne in need of treatment options," said
Curran Simpson, Chief Operating
Officer of REGENXBIO and President and CEO-elect. "Supported by
the strong safety profile and positive microdystrophin data
demonstrated in the AFFINITY DUCHENNE trial, today's news marks
significant steps in rapidly accelerating RGX-202 towards pivotal
stage and future commercialization."
"The Duchenne community remains in need of differentiated
treatment options, and I'm pleased to see the expansion of the
AFFINITY DUCHENNE trial to evaluate RGX-202 in younger patients,"
said Vamshi K. Rao, M.D., Lurie
Children's Hospital, Associate Professor of Pediatrics,
Northwestern University Feinberg School
of Medicine and trial investigator. "With the wider adoption of
newborn screening, there is now an increased opportunity to treat
patients earlier, with the hope of impacting disease and preserving
muscle."
Clinical Program Updates
The Company continues to
rapidly enroll the remaining patients in the ages 4-11 cohort (dose
level 2 expansion cohort) and expects to imminently complete the
enrollment of up to seven patients at dose level 2 early third
quarter of 2024.
REGENXBIO expects to share initial strength and functional
assessment data for both dose levels of the AFFINITY DUCHENNE trial
in the second half of 2024. Initiation of the pivotal trial is on
track for late third quarter to early fourth quarter of 2024.
RGX-202 in the AFFINITY DUCHENNE trial is manufactured using
REGENXBIO's proprietary, high-yielding NAVXpress™ platform process.
This suspension-based manufacturing process has demonstrated robust
scalability with consistent yield and product purity and is ready
for product commercialization.
As of May 3, 2024, RGX-202 has
been well tolerated with no drug-related serious adverse events in
five patients, aged 4.4 to 12.1. All five patients who completed
three-month trial assessments indicate encouraging increases in
expression of RGX-202 microdystrophin and reduction from baseline
in serum CK levels, supporting evidence of clinical
improvement.
AFFINITY DUCHENNE Trial Design
The Phase I/II
AFFINITY DUCHENNE trial is a multicenter, open-label dose
escalation and dose expansion clinical study to evaluate the
safety, tolerability and clinical efficacy of a one-time
intravenous (IV) dose of RGX-202 in patients with Duchenne aged
1-11.
The trial design was informed by the Duchenne community and
engagement with key opinion leaders, including a comprehensive,
short-term, prophylactic immunosuppression regimen to proactively
mitigate potential complement-mediated immunologic responses, and
inclusion criteria based on dystrophin gene mutation status,
including DMD gene mutations in exons 18 and above. Trial endpoints
include safety, immunogenicity assessments, pharmacodynamic and
pharmacokinetic measures of RGX-202, including microdystrophin
protein levels in muscle, and strength and functional assessments,
including the North Star Ambulatory Assessment (NSAA) and timed
function tests.
About RGX-202
RGX-202 has differentiated and
important biology most similar to naturally occurring dystrophin
that protects from the muscle degradation associated with Duchenne.
RGX-202 is designed with advanced science to deliver a transgene
for a novel microdystrophin that includes the functional elements
of the C-Terminal (CT) domain found in naturally occurring
dystrophin. Presence of the CT domain has been shown in preclinical
studies to recruit several key proteins to the muscle cell
membrane, leading to improved muscle resistance to
contraction-induced muscle damage in dystrophic mice. Additional
design features, including codon optimization and reduction of CpG
content, may potentially improve gene expression, increase
translational efficiency and reduce immunogenicity. RGX-202 is
designed to support the delivery and targeted expression of genes
throughout skeletal and heart muscle using the NAV AAV8 vector, a
vector used in numerous clinical trials, and a well-characterized
muscle-specific promoter (Spc5-12).
About Duchenne Muscular Dystrophy
Duchenne is a
severe, progressive, degenerative muscle disease, affecting 1 in
3,500 to 5,000 boys born each year worldwide. Duchenne is caused by
mutations in the Duchenne gene which encodes for dystrophin, a
protein involved in muscle cell structure and signaling pathways.
Without dystrophin, muscles throughout the body degenerate and
become weak, eventually leading to loss of movement and
independence, required support for breathing, cardiomyopathy and
premature death.
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, clinical trials,
regulatory plans, costs and cash flow. 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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