Glysure: a commercial clinical continuous glucose sensor
Submitting Institution
University of BathUnit of Assessment
ChemistrySummary Impact Type
TechnologicalResearch Subject Area(s)
Chemical Sciences: Macromolecular and Materials Chemistry, Organic Chemistry
Biological Sciences: Biochemistry and Cell Biology
Summary of the impact
A commercial continuous glucose sensor/monitor that provides real time
data has been developed by GlySure, a venture capital funded company
founded on the basis of Bath chemistry. The sensor enables Tight Glycaemic
Control (TGC) for control of glucose levels in patients in Intensive Care
Units (ICUs), reducing severe hypoglycaemia, glycaemic variability and the
nursing burden, maximising both patient and economic benefit. This has led
to (i) £13.5M investment in the company GlySure Ltd directly for
development of the system based on the Bath chemistry and (ii) successful
results from full clinical trials of the device, involving more than 200
ICU patients, prior to CE approval and launch in the EU.
Underpinning research
The research has been carried out by Professor Tony James, as part of the
work by his group in the synthesis of a range of organic compounds for use
in sensing applications. James' work maps to the Sensing & Healthcare
theme within Bath Chemistry, and is a major component of the CASE
(Catalysis and Sensing for our Environment) initiative led by Bath.
The capacity of boronic acid receptors to bind diols effectively in water
has made boronic acids the receptor of choice in the James group at the
University of Bath, where he has shown that in order to develop saccharide
selective receptors systems with two boronic acids must be prepared. Such
sensors, pioneered at Bath, consist of three components; a receptor, a
support/spacer, and a read-out unit. The unique element of selectivity for
glucose is imparted by the specifically configured diboronic acid receptor
that is covalently linked to the fluorophore and forms part of the single
molecule indicator chemistry.
The James group research has shown that in order to prepare a D-glucose
selective fluorescence sensor, two boronic acid units (only through two
point binding can saccharide selectivity be engineered), a hexamethylene
linker (D-glucose selective spacer) and a fluorophore (read-out) must be
included [1, 2]. The sensor used in the current system developed by
GlySure Ltd consists of two boronic acids, hexamethylene linker and
fluorophore which is then attached to a hydrogel polymer.
The chemistry has been developed over the last decade [3, 4], and has
been funded by a combination of research council, direct industry and DTI
funding [5]. The specific application in glucose sensing that is relevant
to the commercialisation and clinical implementation has been patented (US
7358094) and following the purchase of this patent from Beckman-Coulter by
GlySure Ltd, the continued development of the chemistry has focused on the
specific requirements of the GlySure sensor system [6].
The development of these technologies has been furthered, into human
clinical testing, with GlySure's resources and expertise focused on
completion of existing fluorescent intensity based measurement systems
using the Bath chemistry. The targeting of this work towards the GlySure
sensor has led to Professor James' appointment as Scientific Advisor to
GlySure Ltd, emphasising the direct link of the Bath-developed chemistry
to the product.
Timeframe
The work relevant to the development of the development of the sensor
being used by GlySure Ltd in its devices has been carried out in the
timeframe since 2001. The critical step of incorporating established
boronic acid sensors into appropriate polymer support matrices and their
optimisation and development for operation in the responsive flow
environment was carried out initially between 2002 and 2005. This element
of the research, crucial to the GlySure technology, resulted in a patent
filed in 2003 ("Sensor system for saccharides"; see Section 5), and has
been developed subsequently in ongoing research by the James group in Bath
[6].
Key Researchers
Professor Tony James (Bath since 2000; synthesis of sensor molecules and
support scaffolds; lead academic)
K. A. Frimat (2008-2012; PhD student in James group); S Arimori
(2000-2001), S E Flower (20003-2008). N P Barwell (2008-2011); PDRAs in
James group
References to the research
[1] S. Arimori, M. L. Bell, C. S. Oh, K. A. Frimat and T. D. James, Chem.
Commun., 2001, 1836-1837. Modular fluorescence sensors
for saccharides [DOI: 10.1039/b105994g]
[2] S. Arimori, M. L. Bell, C. S. Oh, K. A. Frimat and T. D. James
(2002), J. Chem. Soc., Perkin Trans. 1, 803-808. Modular
fluorescence sensors for saccharides [DOI: 10.1039/B108998F]
[3] T. D. James (2007). Top. Curr. Chem., 277, 107-152. Saccharide-selective
boronic acid based photoinduced electron transfer (PET) fluorescent
sensors [DOI: 10.1007/128_2007_110]
[4] R. Nishiyabu, Y. Kubo, T. D. James, and J. S. Fossey (2011). Chem.
Commun., 47, 1106-1123. Boronic acid building blocks:
Tools for sensing and separation [DOI: 10.1039/c0cc02920c]
[5] Direct industrial / translation funding
Total of £344k
including: EPSRC/DTI, (DT/F00267X/1; with GlySure and Gilden Photonics)
2007-2009 (£247k); Knowledge Transfer Partnership (KTP) (with GlySure)
2010-2011 (£47k); Impact Acceleration Account Award (with GlySure) 2013-
(£50k)
[6] S.D. Bull, M.G. Davidson, J.M.H. van den Elsen, J.S. Fossey, A.T.A.
Jenkins, Y.B. Jiang, Y. Kubo, F. Marken, K. Sakuyrai, J.Z. Zhao, T.D.
James (2013). Acc. Chem. Res., 46, 312-326. Exploiting
the Reversible Covalent Bonding of Boronic Acids: Recognition, Sensing,
and Assembly. [ DOI: 10.1021/ar300130w]
Details of the impact
"[Our] development of medical devices for glucose detection, inward
investment in our company and successful clinical trialling of these
devices ... has relied heavily on the underpinning developments from
[Bath] Chemistry research, and on our ongoing interactions in
translating [this] into forms appropriate for commercialisation and
clinical implementation." [A]
Impacts from this work: company, investment, people, new technology,
clinical testing
- A spin-out or new business has generated revenue or profits (GlySure
Ltd; £13.5M new investment in REF period directly attributed to
the Bath research [A])
- Highly skilled people having taken up specialist roles that draw on
their research (GlySure staff expansion to 30, largely in technical
scientific roles; including a Senior Chemist at Glysure recruited
from Bath)
- A new diagnostic or medical technology has been developed and trialled
with patients (glucose sensor developed; full, successful, clinical
trials carried out)
Clinical Need, GlySure Ltd, and Economic Impact
The development of an invasive fibre optic continuous glucose
sensor/monitoring system is in direct response to the clinical need
demonstrated by a seminal clinical study in 2001 [B], which showed that
continuous intensive administration of insulin (allowing tight glycaemic
control) reduced patient mortality by 40% and morbidity by 37-46%, the
latter reducing patient length of stay in the Intensive Care Unit (ICU)
thus providing economic benefits. GlySure Ltd was founded in 2006 to
exploit the Bath-developed research [C], with a 20% equity stake held by
the University of Bath. Based in Abingdon, Oxfordshire, it is a venture
capital funded company with 30 employees, focused on the development and
launch of a continuous real time invasive optical glucose sensor utilizing
fluorescent intensity measurements that allows the development of
continuous glucose monitoring systems in hospital ICUs. GlySure Ltd was
the lead organization in partnership with Bath and Gilden Photonics on a
DTI grant, resulting in new IP filings covering long lifetime dendrimer
fluorophores and synthesis of an alternative diboronic acid receptor
structure from the Bath research [D]. The automated and continuous dosing
and response nature of the GlySure device greatly reduces the nursing
workload required to implement tight glycaemic control, and helps to
improve compliance.
The GlySure target market includes the medical and surgical ICU units of
acute care hospitals. Global admissions in these units alone are
approximately 8.6 million per year, representing a market opportunity of
approximately $1.5 billion for sensors. Initial investments resulted for
GlySure, to develop and build the Bath chemistry into the glucose sensors,
which has since been followed, in January and November 2012, by
further tranches of investment on completion of the initial successful
clinical trials [E], £13.5M of which directly results from the devices
developed from the Bath chemistry [A]. GlySure Ltd has thus
established itself as a secure and expanding UK-based company offering
highly skilled employment opportunities. GlySure continue to invest in
Chemistry developments at Bath and have appointed Professor James as
Scientific Advisor: "Based at the University of Bath, Dr. James is
generally accepted as the world's expert in boronic acid fluorophore
chemistry. He has played a pivotal role in optimising glucose selective
indicator chemistry for continuous measurement in whole blood" [F].
IP Acquisition and Technology Development
The technology development work has been led from Bath, following the
development of the initial chemistry by James; GlySure acquired relevant
IP [C] from the more instrument-focused Beckman Coulter and invested
direct funding in the James group in Bath to develop the chemistry further
towards the function and performance of the appropriate sensor molecules
in the required sensing environment [D] Since 2008, through a series of
funded industry academic transfer projects [5, above], the chemistry has
been incorporated into devices ready for implementation in the clinical
environment. To meet the clinical and commercial need, the technology
developed by GlySure for ICU applications has required the translation by
James of the fluorescent/receptor glucose indicator chemistry developed in
Bath into an optimised form for in situ sensor operation,
immobilised into an optical cell that is micro machined into the fibre.
These sensors have advantage over other existing glucose sensor in terms
of cost, stability and the ease of the fluorescence measurements, as
corroborated by advantages highlighted by Senseonics, a US company in this
domain: "The fluorescent glucose chemistry is ... not subject to the
instabilities intrinsic to current protein based glucose sensors...
Consequently, this technology is expected to be inherently more stable and
accurate." [G].
Clinical Testing
Since 2008, GlySure have used the Bath-developed chemistry as a
fundamental underpinning feature of their sensor device, which is intended
to act as the active glucose sensor in clinical settings. The sensors were
tested in vivo (in pigs) in 2008-2009, and the sensors entered
clinical trials in India in 2010. Successful clinical testing has been
carried out in the ICU environment and presented at the International
Symposium on Intensive Care and Emergency Medicine, attracting more than
2000 physicians, nurses and other healthcare professionals, and the World
Federation of Societies of Intensive and Critical Care Medicine [H]. Over
two years of human use trials, the GlySure continuous glucose monitoring
system has been tested in over 200 intensive care patients to date, in the
challenging environment of the ICU. The impressive results from these
clinical trials [H-J] show that the GlySure system is capable of
monitoring throughout the length of a patient's stay in the ICU.
Scope for Growth
In addition to the ICU device described, the fluorescent lifetime glucose
sensor has been incorporated into a development programme to create a
small, easy to use continuous glucose sensor for the home diabetic market.
This lifetime sensor device would allow expansion of the devices into the
home market which is estimated at £1.5 to £2 billion annually.
Key Impacts Summary
2008-2009 - In vivo testing of GlySure device, incorporating
Bath-developed sensor technology
2010-2011 - Clinical trials, India; more than 150 patients
2012 - Clinical Trial outcomes reported, two rounds capitalisation for
Glysure, £13.5M of which results directly from the Bath chemistry
2013 - Clinical trials extended to 200 intensive care patients
2013 - Device enrolled for CE regulatory trial for approval in Europe
Sources to corroborate the impact
[A] Letter of evidence of impact, CTO and Director, Glysure Ltd
[B] Van den Berghe et al (2001). New England Journal of Medicine,
345, 1359-1367. Intensive insulin therapy in critically ill
patients [DOI:
www.nejm.org/doi/full/10.1056/NEJMoa011300]
[C, D]IP/patents
[C] M. L. Bell, T. D. James, S. Arimori, Sensor system for
saccharides, US 7358094 (2008); filed in 2003, with Beckman-Coulter;
subsequently acquired by GlySure.
http://worldwide.espacenet.com/publicationDetails/biblio?II=1&ND=3&adjacent=true&locale=en_E
P&FT=D&date=20041118&CC=WO&NR=2004099778A1&KC=A1
[D] B. C. Crane, T. D. James, J. S. Fossey, N. P. Barwell, Indicator
System for Fiber Optic Sensor WO/2011/101624 (2011); for chemistry
developed explicitly in Bath for the Glysure sensor applications
http://worldwide.espacenet.com/publicationDetails/biblio?DB=worldwide.espacenet.com&II=7&ND
=3&adjacent=true&locale=en_EP&FT=D&date=20130307&CC=US&NR=2013059394A1&KC=A1
[E] Capitalisation
Two major rounds of capitalisation in the REF period:
http://www.glysure.com/media-centre/press-releases/new-funding-round/
"GlySure, developer of in-hospital continuous blood glucose monitoring
systems, today announced
the close of its £7 million Series C financing round" (9 January 2012)
http://www.glysure.com/media-centre/press-releases/series-c-second-closing/
"Glysure Completes Series C Second Closing for a Total of £8.5M" (29
November 2012)
[F] Quotation taken from GlySure Website listing Professor James
as Scientific Adviser
http://www.glysure.com/about/directors-advisors/
[G] http://senseonics.com/product/the-sensor
[H-J]Clinical Trials
Results presented at ISICEM2012 and WFSICCM clinical conferences, and
highlighted by the NIHR (National Institute for Health Research) Horizon
Scanning Centre
[H] http://www.glysure.com/clinical-data/icu-pilot-trial/
[I] ISICEM2012: Mulavisala KP, Gopal P, Crane B et al.
Preliminary ICU experience of a novel intravascular blood glucose sensor.
Accuracy of a continuous intravascular glucose monitor in ICU patients.
32nd International Symposium on Intensive Care and Emergency Medicine
(ISICEM). March 2012. Poster P175
http://www.glysure.com/media/14997/glysure_poster_isicem_final.pdf
WFSICCM:
http://www.glysure.com/media/23434/glysure_poster_durban_2013_updated_v2.pdf
[J] National Institute for Health Research (NIHR) Horizon Scanning
Centre, University of Birmingham, May 2013. Glysure intravascular
continuous glucose monitoring system for glycaemic control in intensive
care
http://www.hsc.nihr.ac.uk/topics/glysure-intravascular-continuous-glucose-monitorin/