Download XEN Gel Stent for glaucoma treatment

Technology
ALERT
Horizon Scanning Centre
February 2015
XEN Gel Stent for glaucoma treatment
TECHNOLOGY
The XEN Gel Stent is a glaucoma drainage implant
developed by AqueSys, Inc, and distributed in the UK
by Kestrel Ophthalmics Limited. Its aim is to reduce
intraocular pressure (IOP) in patients with primary
open angle glaucoma where previous medical
treatments have failed.
The XEN Gel Stent is a permanent, soft, collagenderived, gelatin implant. It is 6mm in length and is
about the width of a human hair. It is placed through
a small (approximately 1.6mm), self-sealing, corneal
incision via a preloaded injector with a small 27g
needle. Using an ab interno (from the inside)
approach, the surgeon advances the inserter across
the anterior chamber into the quadrant of the eye
where implantation is planned. This small incision
approach to glaucoma surgery is known as
microinvasive glaucoma surgery (MIGS).
Upon implantation the XEN Gel Stent creates a
channel through the sclera allowing flow of aqueous
humour from the anterior chamber into the
subconjunctival space to reduce IOP. The pliability
and softness allow it to conform to the ocular tissue. It
can be used as a stand-alone procedure or in
combination with cataract surgery.
© Aquesys, Inc
The XEN Gel Stent received a CE mark in November 2013 and the company are planning a
stepwise commercial UK launch in 2015.
Other microinvasive stents are in development, including the InnFocus MicroShunt™ by
InnFocus Inc which also targets subconjunctival drainage. This shunt uses Mitomycin C to
This alert presents independent research funded by the National Institute for
Health Research (NIHR). The views expressed are those of the author and
not necessarily those of the NHS, the NIHR or the Department of Health.
NIHR Horizon Scanning Centre, University of Birmingham
Email: [email protected]
Web: www.hsc.nihr.ac.uk
NIHR Horizon Scanning Centre
modulate wound healing and implantation is via an ab externo fornix-based conjunctival
incision. It is CE marked (January 2012), but no further information is available.
POTENTIAL FOR IMPACT
Primary open angle glaucoma is a chronic disease involving the trabecular meshwork, which
is the area of tissue around the base of the eye responsible for draining the aqueous humour
from the eye. It becomes partially blocked preventing the aqueous humour draining properly
and raises IOP. Raised IOP is a major risk factor for the development of glaucoma, a family
of conditions characterised by optic neuropathy manifested by the loss of optic nerve fibres.
Current treatment of raised IOP initially involves a variety of drug treatments. If these do not
work, a variety of surgical options can be considered. One of these is the use of glaucoma
drainage implants (tube shunts), such as the XEN Gel Stent. The company claim the
potential benefits of the XEN Gel Stent include a sustained reduction of IOP through the
subconjunctival outflow pathway – making it the only MIGS procedure that bypasses all
potential outflow obstructions. The company also claim that the XEN Gel Stent is designed
to reduce the complications of traditional glaucoma surgery through the use of a quick (up to
10 minutes) and less invasive ab interno procedure. This type of procedure does not require
conjunctival or scleral dissection, which reduces tissue trauma. As a result of this, the
company state that there may be fewer postoperative complications and patient recovery
may be faster. As there is no trauma or dissection to the conjunctiva, the tissue can also be
re-treated in the future, if needed. The company state that the AqueSys gelatin used in the
XEN stent is well accepted by the human body, and is non-inflammatory. They also claim
that the soft gelatin material minimises complications (such as erosion and corneal
endothelial damage) related to currently used synthetic materials.
If clinical and cost effectiveness can be demonstrated, the XEN Gel Stent may offer an
additional treatment option for patients with primary open angle glaucoma.
This technology is predicted to have an impact on the following domain of the NHS
Outcomes
Framework
(www.england.nhs.uk/resources/resources-for-ccgs/out-frwrk):
Domain 2 - Enhancing quality of life for people with long-term conditions.
EVIDENCE
PUBLISHED PAPERS
Lewis RA. Ab Interno approach to the subconjunctival space using a collagen glaucoma
stent. Journal of Cataract & Refractive Surgery 2014;40(6):1301-1306.
http://www.ncbi.nlm.nih.gov/pubmed/24943904
CONFERENCE POSTERS AND ABSTRACTS
Rękas M, Lewczuk K, Jabloríska J et al. Two year follow-up data with a soft and permanent,
minimally-invasive ab-interno subconjunctival implant in open-angle glaucoma subjects.
European Society of Cataract & Refractive Surgeons, London 2014. Poster.
http://www.escrs.org/London2014/programme/posters-details.asp?id=20885
Reitsamer H. Early results of a minimally-invasive, ab-interno gelatin stent in combination
with a preoperative Mitomycin C injection for the treatment of glaucoma. European Society
of Cataract & Refractive Surgeons, London 2014. Poster.
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NIHR Horizon Scanning Centre
http://www.escrs.org/london2014/programme/free-papers-details.asp?id=21471&day=0
Kersten-Gomez I and Dick H. First results of the innovative minimal-invasive glaucoma
surgery technique: the AqueSys Aquecentesis procedure. European Society of Cataract &
Refractive Surgeons, Milan 2012.
http://www.escrs.org/milan2012/programme/free-paper-details.asp?id=14101&day=0
Arciniegas-Perasso CA.Marí-Cotino JF, Vila-Arteaga J et al. XEN implant: Our experience in
the first 19 patients. European Glaucoma Society, France 2014. Abstract P300.
http://www.oic.it/~egsnice2014/documenti/abstracts/P300.pdf
ONGOING STUDIES
ClinicalTrials.gov. A prospective, multicentre clinical trial designed to evaluate the safety and
performance of the AqueSys XEN 45 glaucoma implant in subjects with refractory glaucoma.
https://clinicaltrials.gov/ct2/show/NCT02036541
ClinicalTrials.gov. Post market multicentric evaluation of the AqueSys XEN implant in
moderate primary open angle glaucoma subjects.
https://clinicaltrials.gov/ct2/show/NCT02006693
COMPANY INFORMATION
The company have completed enrolment of a 20 site 220 eye European phase IV study and
are currently in the enrolment phase of a clinical study within the US.
INFORMATION FROM
This Alert is based on information from the company and a time-limited internet search.
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