The Development of Stem Cells for Regenerative Medicine
Submitting Institution
University of SheffieldUnit of Assessment
Biological SciencesSummary Impact Type
HealthResearch Subject Area(s)
Biological Sciences: Biochemistry and Cell Biology
Technology: Medical Biotechnology
Summary of the impact
Research on stem cells has led to an explosion of interest in the field
of regenerative medicine, with the potential for new clinical
interventions and treatments. Pioneering research in Sheffield led to the
founding of a spin-out company, Axordia, in 2001, focussed on the
applications of human embryonic stem cells (hESC) in medicine. Several
hESC lines (including SHEF-1) were generated in Sheffield by Axordia,
which was sold to Intercytex in 2008 for £1.68M. These Sheffield-derived
hESC lines were then sold on to a major pharmaceutical company, Pfizer,
for £0.75M in 2009. As a result, a clinical grade derivative of SHEF-1 has
been developed and approved for clinical trials for treating age-related
macular degeneration (AMD). In addition, Sheffield research has led to the
licensing and sales of key hESC marker antibodies for stem-cell quality
control. Finally, Sheffield researchers have informed emerging regulatory
guidelines about the safety of hESC regenerative medicine applications by
authoring reports and providing evidence to a Parliamentary committee. The
case study has significant impact on commerce, health and welfare and
public policy.
Underpinning research
Embryonal carcinoma (EC) cells, the malignant counterparts of human
embryonic stem cells (hESC), were the only available pluripotent human
stem cells until hESC were first reported in 1998. Professor Peter
Andrews, Co-Director of the Centre for Stem Cell Biology at the University
of Sheffield, pioneered human EC cell research and was the first to work
with hESC in the UK, with lines acquired from Dr James Thomson in 1999.
Andrews co-founded the spin-out company Axordia Ltd In 2001, which derived
a unique portfolio of hESC lines, including the SHEF lines. In addition,
Andrews characterized several monoclonal antibodies that are used to
identify both EC cells [R1] and hESC [R2], and he studied
their differentiation into neural cell types [R3]. Continuing this
line of work, in collaboration with Peter Coffey, (initially in Sheffield,
and later at University College London), he demonstrated that neural cells
derived from hESC would integrate well when transplanted to the eyes of
newborn rats, and that among these cells retinal pigment epithelial (RPE)
cells could be derived [R4]. This research underpins the impact on
clinical application of hESC for age-related macular degeneration (AMD),
which is the most common cause of vision loss in those aged over 50.
In collaboration with Paul Kemp from Intercytex Ltd, Andrews studied the
reprogramming of somatic cells by fusion with EC and hESC as a potential
route to obtaining pluripotent stem cells (Patents PCT/GB00/00582 and
PCT/GB00/00576 inventors Andrews and Kemp, filed 1999). As a result of his
standing in the stem cell research community, Andrews was asked in 2004 by
the International Stem Cell Forum (ISCF) (www.stem-cell-forum.net/),
a consortium of healthcare funding agencies from 13 countries, to lead the
International Stem Cell Initiative (ISCI). This represented a group of ESC
researchers aiming to compare the different isolates of hESC from around
the world, especially seeking a consensus about surface antigen and gene
expression markers that can be used to identify undifferentiated hESC.
This consortium described a surface antigen and gene expression signature
characteristic of hESC [R5]. The antigens highlighted by the ISCI
study included several (SSEA3, SSEA4, TRA-1-60, TRA-1-81) characterized by
Andrews. The consortium also incorporated a collaboration with ABI Inc to
design a low-density qPCR array to assay the expression of 96 genes by
putative hESC. This research underpins the commercial use of these markers
in the quality control of hESC.
Finally, in another study Andrews showed for the first time that, on
long-term culture, hESC may acquire non-random genetic changes that could
compromise safety in regenerative medicine applications [R6], a
result confirmed in further studies of the ISCI led by Andrews. As a
result of these data, and his long-term leadership in the field, Andrews
was invited to contribute to a UK Parliamentary Committee on regenerative
medicine in 2012, underpinning impact on policy.
References to the research
R1 Andrews PW et al. (1996). Comparative analysis of cell surface
antigens expressed by cell lines derived from human germ cell tumours. Int.
J. Cancer 66: 806-816.
R2 Draper JS, Pigott C, Thomson JA, Andrews PW (2002). Surface
antigens of human embryonic stem cells: changes upon differentiation in
culture. J. Anat. 200: 249-258. doi: 10.1046/j.1469-7580.2002.00030.x
R3 Przyborski SA, Morton IE, Wood A, Andrews PW (2000)
Developmental Regulation of Neurogenesis in the Pluripotent Human
Embryonal Carcinoma Cell Line NTERA-2. Eur. J. Neurosci. 12:
3521-3528. doi: 10.1046/j.1460-9568.2000.00230.x
R4 Vugler A, Carr AJ, Lawrence J, Chen LL, Burrell K, Wright A,
Lundh P, Semo M, Ahmado A, Gias C, da Cruz L, Moore H, Andrews P, Walsh J,
Coffey P (2008) Elucidating the phenomenon of HESC-derived RPE: anatomy of
cell genesis, expansion and retinal transplantation. Exp. Neurol.
214: 347-361. doi: 10.1016/j.expneurol.2008.09.007
R5 The International Stem Cell Initiative (Corresponding Author,
PW Andrews) (2007) Characterization of human embryonic stem cell lines by
the International Stem Cell Initiative. Nature Biotech.
25:803-816. doi: 10.1038/nbt1318
R6 Draper JS, Smith K, Gokhale P, Moore HD, Maltby E, Johnson J,
Meisner L, Zwaka TP, Thomson JA, Andrews PW (2004) Recurrent gain of
chromosomes 17q and 12 in cultured human embryonic stem cells. Nature
Biotech. 22: 53-54. doi: 10.1038/nbt922
Details of the impact
Commercial investment Enabling the Development of Regenerative
Medicine
a) Commercial development of pluripotent stem cells for
regenerative medicine
To exploit the opportunities created by the first derivation of hESC,
Axordia Ltd was founded as a spin-out company of the University of
Sheffield in 2001 with Professors Andrews and Moore (also of Sheffield) as
founding directors [S1]. The initial investment in Axordia from the
White Rose Technology Seedcorn Fund (a £9M scheme funded by contributions
from the then Regional Development Agency, the then DTI and the White Rose
universities) was secured based upon the strength of the underlying
research programmes of the founding scientists (Press Release [S2]).
The patent applications relating to reprogramming somatic cells (that had
been filed by Andrews and Kemp in 1999) were assigned to Intercytex Ltd,
another early stage biotech company working towards regenerative medicine
(who later purchased Axordia). Acquisition of these patents from Sheffield
in exchange for founder shares contributed to Intercytex obtaining its
initial investment of £1.4 million. Andrews served as an Executive
Director of Axordia and was a member of the Scientific Advisory Board of
Intercytex. His research underpinned the patents on hESC and his board
membership contributed to assuring investors of the potential of Axordia
and Intercytex. In 2006, Axordia secured additional investment of £420,000
from BioFusion Ltd [S3]. In particular, collaborative work with
Coffey after his move from Sheffield to UCL on the production of RPE cells
from hESC allowed Axordia to enter negotiations with UCL to provide cells
for future clinical trials for AMD. Pfizer and Coffey have received
approval from the MRHA to carry out clinical trials for AMD using RPE
cells derived from SHEF-1 (letter from Paul Whiting, Pfizer Neusentis [S4]).
The potential opportunities in Regenerative Medicine, exemplified by the
possibility of treating AMD with hESC-derived RPE cells, encouraged Pfizer
to establish a new unit and wholly owned subsidiary, Neusentis (evidenced
by letter from Pfizer Neusentis [S4]). Eventually, Intercytex
purchased Axordia for shares valued at £1.68M in 2008 (Intercytex Press
Release [S5]). In 2009 Intercytex sold Axordia cell lines,
including SHEF-1, to Pfizer for $750,000 (Pfizer Press Release [S6]).
Currently, Pfizer are supporting the clinical trials for AMD using cells
derived from a clinical grade SHEF-1 hESC line isolated at Sheffield under
contract to Pfizer. As stated in the letter from Pfizer Neusentis:
"The hESC line we are using is SHEF1. This was first shown by
Professor Andrews (in collaboration with Professor Coffey at the
Institute of Ophthalmology) to be capable of differentiating into RPE.
Clearly this was critical information to enable the subsequent focus on
SHEF-1 as opposed to other hESC lines."
Thus, this work has had a significant direct commercial impact of several
million pounds (purchase of Axordia hESC lines by Intercytex and Pfizer,
development of Neusentis, and Pfizer contract work at Sheffield), has
influenced commercial decisions of a major pharmaceutical company, and has
influenced the emerging field of novel health outcomes via the generation
of clinical grade stem cells that will be used in human trials.
b) Commercial development of markers for quality control of hESC
A requirement anticipated for the approval of hESC based regenerative
medicine applications is a demonstration, using multiple approaches, that
preparations of differentiated cells for transplantation are not
contaminated with persisting undifferentiated stem cells. One approach is
a demonstration that such preparations do not contain cells expressing
specific surface antigens (such as TRA-1-60) defined by the research of
Andrews. As stated in the letter from Pfizer Neusentis, [S4]:
"Professor Andrews' research showed that a cell surface marker known
as Tra-1-60 identifies pluripotent stem cells such as hESC. This
observation has proven very useful for our cell therapy programme as
using an antibody to Tra-1-60 enables us to identify any contaminating
hESC in preparations of RPE cells. This purity assay is critical to
ensure safety of the therapeutic product, and was a requirement of the
UK regulatory agency, the MHRA"
Following commercial agreement with Andrews, the markers (SSEA3, SSEA4,
TRA-1-60, TRA-1-81) for determining stem cell state are now sold under
licence from the Wistar Institute (a US biomedical centre) by at least 17
companies, including Life Technologies, who acknowledge the work of the
ISCI consortium led by Andrews [S7]. The value of these products is
commercially sensitive but Andrews has received licence revenue from
Wistar [S8].
Regulation of the Clinical Use of Stem Cells
The use of stem cells in regenerative medicine is an emerging field in
which the regulatory authorities are still developing guidelines. Andrews
has contributed to this policy debate by:
a) Informing government policy
Andrews was invited to advise government on hESC research, as an expert
witness to the House of Lords Science and Technology regenerative medicine
inquiry in 2013 (House of Lords Report [S9]).
b) Safety and regulatory approval
Andrews' research led to the recognition by regulatory authorities that
genetic change can occur in hESC and that this must be taken into account
in safety assessments of hESC-based regenerative medicine. This
requirement relates directly to the research performed by Andrews. For
example, documentation about the absence of such genetic changes (e.g.,
gains of chromosomes 17 or 12) was required before the UK government
agency, the Medicines and Healthcare products Regulatory Agency (MHRA),
provided approval for the planned UCL/Pfizer AMD clinical trial (see
letter from Pfizer Neusentis, [S4]).
The development of regenerative medicine, particularly based upon hESC,
is a national priority of the UK government and research councils. It is
recognized that this development requires active commercial investment,
which must be underpinned by the strength of the UK research and
regulatory environment. Prof Andrews' activities have had considerable
impact in the development of policy and in the commercialisation and
testing of hESC lines for research and clinical use.
Sources to corroborate the impact
S1 Information on Axordia Ltd available at Bioity.com
www.bionity.com/en/companies/12384/axordia-ltd.html
S2 White Rose Technology Seedcorn Fund Press Release. 12 November 2001
`White Rose investment sees Axordia at cutting edge of stem cell
research'. Provides evidence of the initial investment of £250,000
in Axordia as start-up company `to extend their leading stem cell research
and to develop therapeutic treatments for a range of debilitating
diseases'. Available at www.kazwoz.nildram.co.uk/whiterose/new/axordiapress.html
S3 BioFusion Press Release, 20 January 2006 `Funding to further
advance Axordia's stem cell programmes'. Provides evidence of
further capital investment of £420,000 in Axordia. Available at: www.fusionip.co.uk/wp-content/uploads/2013/09/axordia_financing_release.pdf
S4 Letter from Professor Paul Whiting, Executive Director Pfizer
Regenerative Medicine, Cambridge UK: provides evidence of the
commercial choices made by Pfizer in the choice of SHEF-1 line for
clinical trials, the role played by Peter Andrews in their development,
and the use of Andrew's markers as part of regulatory requirement by
Medicines and Healthcare products Regulatory Agency (MHRA). Cited in text
above and available on request.
S5 Intercytex Purchase of Axordia for £1.68M in 2008. Evidence of
commercial impact of Axordia within REF period. Details available from
Bloomberg and Interactive Investor websites at: www.bloomberg.com/apps/news?pid=newsarchive&sid=axLHnX5kJX3g
www.iii.co.uk/investment/detail?code=cotn:FIP.L&display=news&it=le&period=2008
S6 Press releases on Pfizer's collaborative and licensing agreement
with Intercytex and its purchase of Intercytex assets in 2009.
Available from:
www.evaluategroup.com/Universal/View.aspx?type=Story&id=183892
www.uclb.com/news-and-events/news-post/pfizer-secures-assets-from-intercytex-to-support-ucl-collaborative-research-project
S7 Details of commercial use of antibody markers developed by the
Sheffield group in the TaqMan® Array Human Stem Cell Pluripotency Panel
marketed by Life Technologies www.lifetechnologies.com/order/catalog/product/4385344
S8 Commercial licensing agreement between The Wistar Institute and
Andrews. Confidential document relating to the commercial value of the
antibody markers developed in Sheffield. Available on request.
S9 Regenerative Medicine Policy Document: Andrews gave oral
evidence to the House of Lords Science and Technology Committee in Oct/Nov
2012. His evidence is cited in House of Lords Science and Technology
Committee Report on Regenerative Medicine, July 2013, available at www.publications.parliament.uk/pa/ld201314/ldselect/ldsctech/23/23.pdf