The concept of using stem cells to correct and replace dysfunctional tissues in the body is a lot older than you might think.
Stem cells – those which can renew themselves and differentiate into other types of cell – were first described in a published paper in 1932 but are alluded to as early as 1908, and were first grown in the lab in the early 1980s.
More than three decades later, the use of stem cells as a therapeutic intervention remains largely in its infancy, although the number of clinical trials is rising year on year.
John Gurdon and Shinya Yamanaka set the field on fire with their pioneering discovery that mature, specialised cells can be genetically reprogrammed to become immature cells – or induced pluripotent stem (iPS) cells – capable of developing into all tissues of the body.
That work earned them a Nobel Prize in 2012, and neatly side-stepped many of the ethical issues surrounding the use of stem cells derived from embryos, as well as providing a route to providing stem cells that are a perfect genetic match for the patient.
Meanwhile, scientists are also starting to understand that there are populations of multi-potent stem cells already present in tissues such as the heart which can be harvested, expanded in culture and administered to patients as a therapeutic intervention.
For example, a trial ongoing in the US is looking at using cardiac stem cells taken from heart attack patients during surgery to see if expanding and re-introducing them to the heart three months later can reduce the size of the infarct in heart tissue.
Prof Martin Evans – who won the Nobel Prize for Medicine in 2007 for his work in the field of embryonic stem cell research – said at a Royal Society of Medicine (RSM) lecture last month that “the advances that we’ve seen in recent years with regards to cell biology leads us to suppose that it will be possible – as long as the logistics and finances are satisfactory – to make cells from each individual patient.”
The caveat is important. The publicly-funded Cell Therapy Catapult (CTC), which was set up last year to spearhead the development of the field in the UK, found 34 verified cell therapy clinical trials ongoing at its last count in April. Following behind are 37 preclinical projects that are around two years from the clinic.
Prof Johan Hyllner, who was appointed chief scientific officer of the CTC earlier this year, gave an update on the sector at a meeting in London in November, noting that the UK is “one of the hottest spots in the world to do this kind of work,” along with the US and Japan.
However the majority of the clinical projects are in the early stages (phase I or II) and it is telling that more than three-quarters are sponsored by academic researchers rather than industry, highlighting that the private sector is so far making fairly limited commercial investments in the sector.
This is a surgical procedure and we need to think of the area – as some regulators do – as a form of pharmacology
In fact, a House of Lords committee reported in July 2013 that the UK is actually underprepared to capitalise on developments in regenerative medicines, thanks to a complex regulatory environment, which it said was holding back private investment, coupled with a lack of coordinated leadership and support for clinical trials.
Recommendations to remedy the situation included additional funding, reducing bureaucracy in cell therapy regulation and looking again at the function of the National Institute for Health and Care Excellence (NICE) as it looks at novel therapies with a high upfront cost but – at least potentially – significant long-term savings. Above all, it says, is the need to ensure that the NHS is mobilised to help develop and provide cell therapies.
The government’s response – published in November 2013 – can largely be condensed to an endorsement of all the Committee’s findings and an assertion that many of them are already being addressed.
Funding via the Biomedical Catalyst, Medicines Research Council, National Institute for Health Research (NIHR), Technology Strategy Board and medical charities is readily available, it says, while it is now setting up a Regenerative Medicine Expert Group (RMEG) to “develop an NHS regenerative medicine delivery readiness strategy action plan”.
Regulatory reform
One of the key aims of the RMEG will be to try to bring different regulators together with academia, industry and other stakeholders to try to develop a level regulatory playing field, although observers suggest its impact is hard to gauge given that most regulations on cell therapies are mandated at the EU level by the Advanced Therapy Medicinal Products Regulation.
Some believe that fundamental rethinking is needed in the regulation of the field. For instance, Prof Evans questions why the prevailing sentiment seems to be that cell therapies – such as the use of limbal stem cells to repair the cornea – should be subject to the same regulatory pathways as pharmacological treatments.
“This is after all a surgical procedure that can be amplified by taking the cells out and growing them relatively transiently under defined culture conditions,” he said at the RSM event.
Most clinical projects are early stage, and in-roads by the commercial sector have so far been limited
“Of course, safety and efficacy must be of prime importance. But do we need to think of this – as I believe some regulators do – as a form of pharmacology [and require] huge randomised controlled trials?”
On the whole, industry seems pretty happy with the current environment in the UK, although Prof Chris Mason, chair of the BioIndustry Association’s Cell Therapy and Regenerative Medicine Advisory Committee, warned recently that other countries such as Japan and Korea are already streamlining infrastructure to accelerate the delivery of cell therapies into clinical practice.
“The global cell therapy industry is at the important inflection point between spirited pioneering and true commercialisation, according to Mason, introducing a new BIA booklet that showcases the UK as a “must-go-to country for regenerative medicine R&D” with more than £140m in public sector investment in the next few years.
“The UK leads the world in healthcare, finance and stem cell R&D,” he added. “The integration of these major assets, combined with robust government support for regenerative medicine, makes the UK the prime location to invest in cell therapy as it rapidly grows into a multibillion pound sector on a par with pharma and biotech.”
Mason’s view is echoed by Prof Hyllner, who noted that an enormous amount of money is being spent on basic cell therapy science, and the challenge now is to translate that into commercially viable products.
“The purpose of the Catapult is to accelerate those projects into the clinic, not by giving grants but by providing expertise,” he added, noting that business development is often the major knowledge gap among scientists.
The CTC provides advice on business models, manufacturing, health economics and reimbursement considerations, for example, to try to make sure that there is someone to pay the bill for a new cell therapy.
“When the preclinical research is completed, there is sometimes a lack of reality on the challenges involved in providing 100 times the amount of cells in a hospital-treated patient,” said Hyllner.
One of the primary projects for the CTC is to create a bank of IPS cells for use by researchers and to examine the Good Manufacturing Practice (GMP) capacity in the UK for making cell therapies, with the aim in time of establishing a contract manufacturing organisation (CMO) that can be accessed by developers.
Over the next five years, the CTC’s aim is to complete 4-6 clinical projects and participate in the creation of 2-3 “significant investible propositions”, according to the CTC, which has a strategic goal of creating a £10bn cell therapy industry in the UK.
To achieve that objective the sector will need the “market pull” of 63 million NHS patients with appropriate reimbursement in place, according to Mason.
