January 15, 2008 (Vol. 28, No. 2)
Susan Aldridge, Ph.D.
The United Kingdom Is Updating Technology & Training Scientists for Better Biomanufacturing
Without training more bioprocessing specialists, the U.K. could lose its strong lead in bringing biological medicines to market. Investment is now needed to establish Centres of Excellence in bioprocessing to build on the foundations that have been laid by bioProcessUK over the last three years, reported director, Tony Bradshaw, Ph.D., at the organization’s recent conference in Cardiff.
BioProcessUK, a knowledge transfer network funded by the government’s Technology Strategy Board (TSB), is dedicated to supporting the growth of the biopharmaceutical development and processing sector in the U.K. The development pipeline of biotech drugs in the U.K. is the largest in Europe and has roughly the same number of candidates as the U.S. on a per capita basis, according to Bradshaw. “This is not a bad position,” he added. “Bioprocessing can capture more value for the U.K.”
The focus of bioProcessUK in 2007 was on networks, infrastructure, skills and, increasingly, trade and investment. Collaborative research and development in bioprocessing is being undertaken by both the government’s TSB and the Bioprocessing Research Industry Club (BRIC), which is a partnership between industry and the Research Councils. Over £20 million has already been invested in bioprocessing research and education through these initiatives.
“We now want a commitment to long-term funding in this area. We would like to see more Centres with a critical mass of principal investigators to provide a rich training environment,” Bradshaw noted. “Our vision is to have the U.K. evolve into a global hub of bioprocessing education and as a place to develop biological medicines.”
Marketing Life Sciences
BioProcessUK has been working with the U.K. Trade & Industry (UKTI) on the new life sciences marketing strategy, part of a global strategy the government has devised to deal with competition from Asia.
“If we just stand still, we will lose out to growing economies,” said Kevin Cox, Ph.D., of UKTI’s biotech and pharma sector advisory group. “The strategy is led and driven by industry, not government. We have to act as ambassadors, with everyone delivering the same message, that the U.K. is a springboard for global growth.”
UKTI has made life sciences a priority in its marketing strategy, but many other countries are also strengthening their life sciences sector. With so many companies looking for global partners, the competition is getting much more fierce.
Dr. Cox enumerated the U.K.’s strengths: a world-class science base; a clear regulatory framework that is respected worldwide, second only to the U.S. in R&D, innovation, and business growth; a pool of talented healthcare, business, and science professionals; and a supportive government. These qualifications need to be promoted to other companies.
“The U.K. is an honest country to do business with,” Dr. Cox concluded. The downside of the U.K., however, includes its high operating costs compared to countries like China. Geographical distance from the U.S. and Asia could also be seen as a disadvantage, and there is a long history of poor commercial exploitation of research. There is also the danger of mixed marketing messages being publicized from the various devolved administrations and regions of the U.K.
And then there is the National Health Service (NHS), seen as both a great asset and a major weakness by the life science industry, depending on one’s perspective. “The NHS could be an important service provider for clinical trials,” said Dr. Cox. “We want to build it up as a strength for the industry.”
A life science marketing strategy will be implemented this year, with a high-level chairman from industry as coordinator. His role will be to connect the marketing strategy with bioProcessUK’s strategies through developing the Centres of Excellence, (e.g., establishing a Centre in Manchester focused upon systems biology), and ensuring that all the proposed Centres are complementary and not competitive.
Meanwhile, TSB and BRIC are funding a wide range of bioprocessing research across the U.K. Paul Dalby, Ph.D., of the University College of London (UCL), which has a long-standing reputation for innovation in this area, described collaborations with many companies in regenerative medicine, chiral pharmaceuticals, ultrascale-down technology, and protein engineering for manufacturability of biotech products. They are also interested in synthetic and systems biology and have also managed to create new pathways in E.coli using engineered enzymes.
“It is an exciting time for us in this program,” said Dr. Dalby. Another UCL project, with BRIC, is in novel microfluidics for protein stability studies in process engineering and protein formulation.
Downstream processing is another key area for bioProcessUK. “Downstream costs, including separation, are 80 percent of the final cost of goods, and separation is starting to become a serious bottleneck,” reported David Stuckey, Ph.D., of Imperial College London. “The cost of goods will only decrease if production processes are integrated and optimized. This is the norm in chemical engineering but not in biopharmaceuticals.”
The root of this disconnect is probably that, in production of a biologic, upstream processes like cell development are about biology, while the downstream processing is more about engineering. Dr. Stuckey believes that it is time to re-examine some of the older technologies, so the team at Imperial has been looking into solvent extraction. Traditionally, this has been nonselective and uses solvents that are hazardous and not biocompatible. What is needed is a more tunable system for extraction of biologic products.
The Imperial team is investigating reverse micelle (RM) extraction of proteins, where a surfactant traps a target protein thereby forming a micelle with a hydrophilic core. Forward and reverse extractions are carried out with a fermentation broth. Dr. Stuckey has tried this approach with lysozyme, ribonuclease, and cytochrome C to see if these could be selectively extracted from mixtures of the three. The experiments were also repeated with real fermentation broths. The back-extractions proved to be slow, but could be sped up by the addition of a counter-ion surfactant.
To scale up the procedure, a Graesser extractor is used to avoid the intractable emulsion that would otherwise inevitably form. “We have proved that this can work on a large scale,” said Dr. Stuckey. They are now looking at the RM approach for mAbs, working with Cambridge Antibody Technology, which is now a part of AstraZeneca (www.astrazeneca.com). The monoclonals, even though bigger molecules, are actually extracted faster than lysozyme.
While iso-octane has been used successfully as a solvent in this work, some companies don’t like it because it is flammable. However, good results can be obtained with vegetable oil, especially corn oil, extraction. Dr. Stuckey is now working on proving that extraction and back-extraction do not change the activity of the protein product.
At Sheffield University, Sheila MacNeil, Ph.D., cofounded CellTran™ (www.celltran.com), based upon work with skin cells. “The nonhealing ulcer costs 10–15 percent of the NHS budget and it is an increasing market because of the increase in diabetes,” she noted. “Although burns are not a big market, we did start out by looking at a better way of delivering cells to burn patients.”
Cultured epithelial autografts (CEA), which use the patient’s own cells, have been the standard approach for major burns and are clinically successful. An audit from Dr. MacNeil’s team found, however, that there are problems with the product, because more than 50% of the time, it is not used; the main problem being the timing of their detachment for application to the patient.
Simple detachment of these cultured skin cell grafts is difficult and, put simply, this is a product with an inflexible shelf life that demanded improvement.
Myskin™, the lead product of CellTran, is engineered to be a PostIt note-like autologous skin graft based on keratinocytes—easy to stick to the graft during transportation and easy to detach when needed by the surgeon.
“Myskin is a cell delivery surface for keratinocytes,” explained Dr. MacNeil. “The product is only part of a whole wound management system because it performs best if it goes onto a good wound bed. Myskin acts like a biological bandage and it has been used on a range of patients including those with diabetic foot ulcers and chronic venous ulcers.” Compared to CEA, Myskin is easier to transport from the lab to the patient, reported Dr. MacNeil. “We have really achieved flexibility in timing delivery.”
CellTran merged with Xcellentis in 2006, which gave it access to more allogeneic keratinocyte products. Other products in development include a contact lens system for treatment of corneal diseases and a keratinocyte/melanocyte treatment for the skin pigmentation disorder vitiligo.
“Tissue engineering in the U.K. is happening on a small scale at the moment,” commented Dr. MacNeil. “This will have to change as patient demand grows and there is more demand for scale-out.”
Other U.K. groups are looking at issues around the yield of biotech products. For instance, David Archer, Ph.D., of Nottingham Biopharm, a Centre of Excellence at the University of Nottingham, described the Centre’s work on yeast as a host, and the various factors that affect yield of heterologous proteins, commenting that the sequencing of over 60 yeast genomes is helping to drive the research.
Meanwhile, Alan Dickson, Ph.D., of Manchester University is studying epigenetic silencing that reduces yield by decreasing the amount of mRNA. The site of heterologous gene insertion is a key issue here and his group is looking at how to engineer vectors to stop silencing.
Dr. Dickson’s team relies heavily upon a systems biology approach to select high-producing cell-lines. “We found that a good cell line depends upon many poorly characterized, interacting events,” he said. “We, therefore, collect lots of data from microarrays and proteomic studies.”
Gene-based therapies are another challenge for the bioprocessing community, and there is much to learn from the achievements of Ark Therapeutics (www.arktherapeutics.com), which is manufacturing a gene-based medicine, Cerepro™, in Finland. The therapeutic is a replication-deficient adenoviral vector with a herpes simplex thymidine kinase (TK) gene inserted, which is intended for the treatment of glioblastoma.
After an injection of the therapy, the standard anticancer drug, gangciclovir, is added. TK phosphorylates the drug, making it cytotoxic to dividing cells. Therefore, this is a prodrug gene therapy, rather than a gene replacement. Neither component is new, but Ark Therapeutics’ way of packaging is innovative, according to Minna Nokelainen, Ph.D., manufacturing development director. Cerepro is made in mammalian cells and purified by centrifugation, filtration, and, increasingly, chromatography.
“The product is live, so we need to do sterile filtration,” explained Dr. Nokelainen. She pointed out that the regulatory authorities have many guidelines for the GMP of such a product. It is characterized in several different ways including PCR to identify the transgene, dynamic light scattering for viral particle size, and ratio of total virus to infective virus. “This is important to us and must be under 30. It tells us how good the product is,” she added. Potency is determined by the activity of the transgene in cell culture.
Funding for Centers
In the near future, bioProcessUK will be working on getting the funding needed to establish its Centres of Excellence in bioprocessing research. For example, Imperial College London now has a lectureship in bioprocessing that is funded by Lonza. Such events will help foster the development of the academia-industry interface in U.K. bioprocessing and help the sector achieve its global aspirations.