Susan Aldridge

It has been a long time coming, but stakeholders in the US are now seriously debating a route to market for cheaper copies of biopharmaceutical drugs. The European Agency for the Evaluation of Medicinal Products (EMEA) has led the way on this issue by publishing clear guidelines on what companies must do to get their versions of drugs such as erythropoietin (EPO), an advanced treatment for anaemia, and similar products approved.  

Biotech drugs such as Herceptin and Avastin — monoclonal antibodies approved for treating breast and colorectal cancer — are valued because they have an innovative mode of action. But this value is reflected in the price tag: a biopharmaceutical medicine can cost up to 30 times more than a conventional small molecule drug. Put simply, if everyone who could benefit from a recombinant protein or monoclonal actually received them, it would sink healthcare budgets everywhere. So, of course, there is pressure to produce cheaper copies as patents begin to expire on drugs such as EPO, the interferons (used to treat multiple sclerosis and hepatitis B and C), growth hormone and the clot buster tissue plasminogen activator.  

The debate regarding how cheaper versions of biotech products should be regulated began — on both sides of the Atlantic — around 3 years ago. At the time, there was much confusion over what these drugs should be called — biogenerics, generic biologics, follow-on biologics or biosimilars. In Europe most people now refer to 'biosimilars' — a term introduced by EMEA in early drafts of its regulatory framework. "The word biosimilar reflects the fact that these drugs are not generic in the same way as small molecules," explains Andrew Fox, a regulatory expert for Amgen — a company that produced some of the first biotech blockbusters such as EPO and G-CSF (granulocyte colony stimulating factor, which is used to protect the bone marrow in cancer chemotherapy). Manufacturers can be assured that a generic version of a small molecule drug really is identical to the original because chemical synthesis is, generally, reproducible, and well-established analytical techniques such as mass spectrometry (MS) can provide a full characterization of the molecule. Biologic drugs are made in living cells and their manufacture is, by its very nature, less predictable and reproducible.  

A pharmaceutical manufacturer hoping to enter the biosimilars market would actually face a double challenge. First, it is harder to make biotech drugs than small molecules because of their increased complexity. "There is a quantum leap between making chemicals and making proteins," warns Fox. Additionally, making a biosimilar involves making a copy of someone else's protein without their experience and know-how (which the innovator can keep secret indefinitely). 

A major issue in biosimilar manufacture is that big molecules, such as antibodies and proteins towards the higher end of the molecular weight spectrum, are difficult to characterize fully with the current range of analytical technologies. "When it comes to characterizing proteins there is not one test and one answer. It is more a case of doing 20 different tests and getting an answer that does not necessarily describe all the characteristics of the protein," says Fox. "We know that minor differences in biophysical properties can have clinical consequences, but we do not have the ability to predict these as yet."  

Professor Daan Crommelin of the University of Utrecht (The Netherlands) and cofounder of Octoplus, a Leiden-based drug delivery and drug development company, agrees that there is "never a concrete answer" when it comes to characterizing either an original or a copy of a biological molecule. "For the smaller molecules such as insulin or growth hormone, the characterization, and the ability to demonstrate similarities and differences between different versions are easier. The larger the molecule, the harder it is to show real equivalence." 

One problem chemical manufacturers never have to worry about is glycosylation — the tendency of proteins to link some of the amino acids in their sequence with oligosaccharide chains. The glycosylation pattern of a protein can affect its biological activity and can elicit immune responses in patients.  

"Some molecules such as EPO are highly glycosylated and this presents a real challenge," comments Crommelin. The biotech manufacturer is usually dealing with a mixture of molecules with differing glycosylation patterns. "If the process is controlled, at least this mixture is well-defined, but its composition depends upon process conditions, the host cell, downstream processing factors and formulation of the final product," he says. Hence, the biosimilar manufacturer will have to come up with plenty of data to show the regulatory authorities that their product does not have a glycosylation profile that is going to compromise efficacy or, more seriously, patient safety. Companies such as Teva (which markets biosimilars in developing countries), Sandoz and BioPartners are meeting these challenges. Sandoz' Omnitrop, a growth hormone, was the first biosimilar to be approved in Europe (after extended legal wrangles in the European court). But the drug was not without teething troubles — the presence of host cell protein (often an issue in biotech manufacturing) led to antibody generation among some clinical trial participants. Sandoz fixed the problem, but it illustrates the inherent unpredictability of biosimilar production. Valtropin, another growth hormone, from BioPartners, was the second product to be approved by EMEA and biosimilar versions of EPO and G-CSF may soon follow. The costs of biosimilars may turn out to be higher, compared with the original drug, than conventional generics because of manufacturing and regulatory issues. And, of course, biosimilars are versions of relatively old drugs. Biotech companies have hardly been standing still while the drugs now up for copying progressed through their patent lives. Their latest products, and those in the pipeline, are likely to be safer and more effective than the earlier versions — such as Amgen's darbepoetin alfa (Aranesp, an advanced treatment for anaemia, which could be used instead of EPO). Will the patient offered a biosimilar be getting an inferior medicine? That's a debate still to come.  

Articles

It has been a long time coming, but stakeholders in the US are now seriously debating a route to market for cheaper copies of biopharmaceutical drugs. The European Agency for the Evaluation of Medicinal Products (EMEA) has led the way on this issue by publishing clear guidelines on what companies must do to get their versions of drugs such as erythropoietin (EPO), an advanced treatment for anÃ¦mia, and similar products approved.

Why biosimilars are not true generics

Concern regarding the environment has never been greater and pharma and biotech must help to ameliorate the situation. This means adopting a smart manufacturing approach that minimizes chemical hazards, waste and energy. It is encouraging to see Merck & Co. setting an example — earlier this year the company was awarded an environmental 'gold star' for its efforts to reduce greenhouse gases through effective energy management. ENERGY STAR is a US Environmental Protection Agency (EPA) programme that helps business and consumers adopt energy-efficient strategies. Merck has been awarded ENERGY STAR Partner of the Year status for the second year running, becoming the first pharmaceutical company to achieve this.  

Energy efficiency is only one aspect of reducing the 'footprint' of the pharmaceutical industry. The holistic approach to environmentally friendly pharmaceutical manufacture is known as 'green chemistry'; a term coined by Paul Anastas in 1991, then head of Industrial Chemistry at EPA, who worked to develop the concept with John Warner of the University of Massachusetts. Anastas describes green chemistry as: "The design of new products and processes that reduce or eliminate the use and generation of hazardous substances." It aims to go way beyond traditional methods of reducing pollution and look at the whole life cycle of the manufacturing process to ensure its sustainability.  

Green chemistry involves redesigning processes so that more of the raw material ends up in the product, rather than as waste, and searching for more benign solvents — or even no solvents at all if a reaction can be done in the solid state. 

"We use innovative technologies to make our processes cleaner," says Mary Buzby, director of Environmental Technology at Merck. One example, which won the company an EPA Presidential Green Chemistry Challenge Award in 2006, involved redesigning the synthesis of sitagliptin, the active ingredient in the new type 2 diabetes treatment Januvia. Sitagliptin is a chiral β-amino acid derivative. The first generation synthesis was a viable manufacturing process, but involved eight steps, including a number of aqueous workups and several high molecular weight reagents, which ended up creating waste as they were not included in the final molecule. In the second generation synthesis, Merck researchers and their collaborators discovered a new reaction — the asymmetric catalytic hydrogenation of unprotected enamines (protecting groups are to be avoided in green chemistry). The new synthesis involved only three steps; allowed 95% recycling of the rhodium-containing catalyst; increased the yield of sitagliptin by nearly 50%; and cuts waste by approximately 200 kilograms for each kilogram of product. Over the lifetime of Januvia, at least 150 million kilograms of waste (including nearly 50 million kilograms of aqueous waste) will be eliminated. Furthermore, this new reaction is applicable to other pharmaceutical syntheses.  

Catalysis was key to the redesign of this product synthesis. Using catalysts, rather than stoichiometric reagents, is preferred in green chemistry because the former are used in tiny amounts and may be recycled, while the latter merely create more waste. Enzyme catalysts are even better, as they can be used at low temperatures, saving energy and are purely biological (no heavy metals to worry about). This is where biotech companies such as Denmark's Novozymes are important. Recently voted one of the world's top 100 sustainable companies for its all-round performance, Novozymes also won a Presidential Green Chemistry Challenge Award for using its proprietary enzyme Lipozyme as an alternative to conventional hydrogenation in margarine production creating a healthier product (without trans-fats) in a cleaner process. California-based biotech Codexis uses directed evolution technology to develop highly specific enzymes. Three of these were used in a redesigned synthesis that vastly improved the manufacture of the key building block of the cholesterol-lowering drug Lipitor. This development, which also gained a Presidential Challenge Award, dramatically increases productivity and reduces waste, solvents and byproducts.  

Enzyme companies could also help push forward another green chemistry principle of using renewable feedstocks, such as biomass or waste from other processes, rather than fossil fuels. Natural or engineered enzymes can break down the long polymer chains of starch or cellulose to simpler molecules such as ethanol.  

Meanwhile, the pharmaceutical industry has begun to work together to implement green chemistry and sustainable solutions on a global basis. The Pharmaceutical Round Table of the American Chemical Society's Green Chemistry Institute brings many of the big pharmas together including Merck, AstraZeneca, Lilly, GSK and Pfizer. They have listed chemical reactions commonly used in manufacturing drugs, which are associated with either safety or waste hazard concerns, and aim to replace these with greener alternatives.  

Solvents continue to be a major challenge; for example, there is a general wish to eliminate chlorinated solvents. "Merck has made tremendous strides in eliminating methylene chloride from our manufacturing processes," says John Leazer, research fellow in process research. "We are currently evaluating the potential of eliminating other nongreen solvents from our processes." Solvents are also used in the many chromatographic separations performed in drug manufacture. "We have actively pursued the use of supercritical fluid chromatography (SFC) where inexpensive and safe carbon dioxide replaces toxic, flammable and expensive hydrocarbons often used in conventional high performance liquid chromatography," adds Dr Leazer. "SFC technology can reduce solvent usage by as much as 95% and has the additional benefit of reducing organic waste and energy usage. Merck pioneered the use of kilogram-scale preparative SFC in the pharmaceutical industry and now routinely uses this approach in the development of new drug candidates." 

It may seem that biotech manufacture is greener and cleaner from the solvent perspective, as most operations are performed in aqueous solution. But water is not exempt from the green chemistry agenda — it is an increasingly scarce global resource. Therefore, the Pharmaceutical Roundtable intends to next look at the environmental challenges of biotech, as well as small molecule manufacturing.  

Green chemistry involves redesigning processes so that more of the raw material ends up in the product, rather than as waste...

Greener, cleaner and leaner

Stem cell researchers are often in the news as governments and the general public debate which experiments should be allowed to proceed. They often say — usually with the support of industry groups and patient charities — that cells could one day provide cures for degenerative brain disorders, such as motor neurone disease and Alzheimer's. Of course, this work should be supported, but it is important not to raise false expectations because there is a huge manufacturing challenge involved in bringing cell therapies (especially stem cell therapies) from the lab bench into the clinic.  

Cell therapy is part of a new approach called regenerative medicine, which involves using cells, tissues, and possibly whole organs, to heal and repair the human body. Regenerative medicine may be able to achieve what conventional pharmaceuticals have not — effective, long-term treatments for chronic diseases involving tissue damage. Besides brain disorders, these would include arthritis, diabetes, stroke and heart disease — all of which are increasing as the population ages.  

There are two ways of performing cell therapy, each involving different manufacturing issues. Autologous cell therapy uses the patient's own cells; a biopsy is taken, the cells are manipulated and expanded in the lab, and then returned to the patient. In allogeneic cell therapy, donor cells are used as a source of therapy. Conducting autologous cell therapy on a commercial-scale involves 'scaling out' rather than scaling up; it is similar to procedures that already take place in hospital, such as blood transfusion, and may fit as a 'bedside' procedure into the healthcare system. Allogeneic therapy is more akin to conventional (bio)pharmaceuticals in its manufacture. Scale-up is an issue and one that is made more complex by the end-product being a living cell rather than an inert chemical.  

So far, cell therapies have been applied to more than 250000 patients using products either on the market or in clinical trials. Companies such as Organogenesis, Genzyme, Advanced BioHealing and Intercytex have shown how to manufacture cells for applications as skin substitutes and in-joint cartilage repairs. This, however, represents only a fraction of the potential market, even for well-established indications such as skin and bone. If the market is to achieve its potential, then automation must start to play a much larger role in cell manufacturing. 

"Currently, cell therapy is reliant on the manual 'green fingered' approach," says Professor Chris Mason of the regenerative medicine bioprocessing unit at University College London (UCL). "It has given us a great start, but it won't give us an industry." Automation will give cell therapies better quality and consistency, but the technology needed will be more complex than the robotics used in biopharmaceuticals, and the capital outlay may put investors off. However, some companies are beginning to automate small parts of the manufacturing process, while Advanced Cell Technology and Intercytex have built-in automation from the start.  

In manufacturing a small molecule drug, you can at least be sure of the quality of the starting materials. This is not the case in autologous cell therapy. There is no standardized procedure for surgeons to take the biopsy that starts the whole manufacturing process, and there is always the danger of contamination, which means discarding the product. The growth characteristics of cells also vary with the patient's age and state of health — a factor that no precautions can guard against. Therefore, autologous cell therapy has intrinsic unpredictabilities that manufacturers must deal with.  

Meanwhile, the maturation of the industry depends upon recruiting and retaining people with the right skills, which is proving difficult. There are specialized bioprocessing courses at UCL and some companies offer in-house training. "GMP experience is always transferable," comments Dr Paul Kemp, founder and chief scientific officer at UK company Intercytex, which is pioneering cell therapies for applications as diverse as venous and diabetic ulcers, and hair and skin regeneration. He thinks people from pharma may find adopting a nurturing, 'horticultural' approach to cells difficult; they are more used to regarding them as sources of contamination to be eliminated. Nursing cells can be both tedious and stressful. 

However, Mason argues that increased automation may go some way to addressing this problem. He adds that more needs to be done, for both kinds of cell therapies, on cryopreservation and distribution, if the industry is to reach its potential. At present, products are used 'fresh' and have a limited shelf-life, therefore, creating much wastage.  

There is also the issue of regulation. Currently, the EU is working out its new Advanced Medicinal Product Directive and it should come into force sometime over the next year. "The directive will be good for the industry," says Kemp. "We can jump the regulatory hurdles once we know what they are. With more clarity, we will be able to plan our clinical strategy." In the US (presidential vetos of federal funding of human embryonic stem cells [hESCs] aside) the regulation of the cell therapy industry is ahead of the EU position. One of the market leaders, Geron, has been working with FDA on regulation and is poised to begin the world's first ever clinical trial of hESCs later this year. 

There are also significant scientific barriers to overcome before cell therapy becomes a clinical reality. Much more needs to be known about how to expand and differentiate stem cells. It is also unclear how far allogeneic cell therapies will be immunogenic; that is, whether patients will need to take immunosuppressant medication for life (as with transplant recipients). Some of these issues are being addressed by initiatives such as bioProcessUK, which is creating a research interface between academia and industry to solve these problems.  

 "In cell therapy, the product is the process — the health and quality of the cells are mission critical," says Mason. Ultimately, the challenges of cell therapy manufacture can only be resolved by realising the unique nature of the product.  

... there is a huge manufacturing challenge involved in bringing cell therapies (especially stem cell therapies) from the lab bench into the clinic.

Facing up to the cell therapy challenge

At home, the bioprocess engineer recycles his or her plastic bags, bottles and other bits with the rest of us. At work it's a different story, as plastic — and disposable plastic, at that — starts to replace stainless steel in the biopharmaceuticals business. A manufacturing facility today might use disposable filters, membranes, dispensers, connectors and fittings, sensors, storage bags, and bioreactors. Single-use plasticware (made from composite polymers) is being applied in the preparation, sterilization and storage of cell culture media. It is also used in buffer preparation, filtration and sterilization, chromatography and, of course, the production process itself. Big Pharma is also affected by the throwaway revolution, as plastic plays an increasingly important role in fill-and-finish. 

Manufacturers are turning towards disposables because they allow more flexibility than stainless steel; with plastic kit, the production set-up can be constructed afresh for each campaign, which can be especially valuable for multiproduct facilities. For instance, at the newly-opened UK National Biomanufacturing Centre (NBC) the need for flexibility drove an early decision to rely on disposables wherever possible, and many of the big players such as Amgen and Genentech are now replacing stainless steel with plastic. 

Disposables simplify the flow of people and materials through a facility, decreasing both its footprint and amount of equipment needed, as well as minimizing upfront capital costs. Switching to plastic can also help drive down manufacturing costs. The transfer of sterile fluids through various process steps has traditionally been done through an array of stainless steel pipes, valves, manifolds and vessels, all of which must be cleaned and sterilized — operations that must be validated before the system is re-used. "It is just so much easier to throw everything in the bin at the end of the day," explains Dr Richard Dennett, technology transfer manager at Eden Biodesign, which runs the NBC.  

Research shows that the cost of disposables compares favourably with stainless steel. For instance, Andrew Sinclair, managing director of consultancy BioPharm Services, and Miriam Monge, marketing director of Stedim, a leading disposables supplier, conducted a comparison study of single-use disposable bag technology versus fixed stainless steel vessels in the manufacture of a monoclonal antibody using a 2000 L fermentation vessel (typical of the kind of process that is widespread in the industry). Their model found savings of nearly 10% in cost of goods from using disposables, which applied whether the facility was a new build or a retro-fit. The decreased requirement for cleaning was the major factor in these cost reductions.  

But before a manufacturer goes disposable, some tough questions need addressing. First, the supplier must provide reassurance on extractables and leachables as part of their validation package. The former refers to substances that appear when a disposable component is tested by solvents and conditions that are generally harsher than those of the process where it is to be used. The latter are substances that might end up in the final product because of its interaction with the disposable. Both have the potential to cause problems with the regulatory authorities, a prospect that might persuade some to stick with the tried-and-tested stainless steel. 

And is there not something contrary about generating mountains of plastic waste in times when we are all being urged to recycle and consume less? Sinclair and Monge acknowledge this concern. In any case, in purely financial terms, waste management accounts for only a fraction of the production cost and waste water treatment is more expensive than disposables incineration.  

Work is also needed in standardization, validation, supply chain issues and integrating systems. The Bio-Process Systems Alliance (BPSA [

]) is part of the Society of the Plastics Industry and wants to promote confidence in the use of disposables throughout the biotech industry. BPSA brings together the key suppliers including Stedim, SAFC Biosciences, Pall Life Sciences, HyClone and Millipore with a mission to educate, and develop standards and guidelines for disposables that should ease their more widespread acceptance. The International Society of Pharmaceutical Engineers is also doing work in this area.  

Meanwhile, suppliers are moving increasingly towards integrated solutions that make the adoption of disposables so much easier. For example, Invitrogen and Wave Biotech have just agreed to supply media-filled bioreactors. However, disposables are not yet the industry standard in biopharmaceuticals. Both Dennett and Sinclair say it is unlikely the conversion to single-use will ever be universal — the main issue being one of scale. Some large-scale production processes will always require stainless steel vessels. But for small batches (which could become more common with the advent of personalized medicine) and certain products — such as gene therapies and vaccines — production in disposables is highly appropriate. There is also a need for suppliers to keep developing new products; currently there is little available for microbial production of biopharmaceuticals, for example.  

A change in technological culture is always difficult for companies to deal with. Where high-value products, such as monoclonal antibodies, are concerned, new methods may be even harder to accept. With disposables, however, manufacturers have travelled some way up the learning curve during the last 5 years. Large companies will already be moving towards disposables in-house, while academics or small biotechs tend to be fairly open-minded and may have already used plastics in the research setting. Biotech is nothing if not innovative and may not need much more persuading to adopt the throwaway approach. 

Disposables simplify the flow of people and materials through a facility, decreasing both its footprint and amount of equipment needed, as well as minimizing upfront capital costs.

Biopharm turns plastic

I used to work next door to a microbiology lab where bacteria was grown on brain and heart broth. The smell alone was enough to persuade me to stay with synthetic organic chemistry and keep well away from the black art of cell culture. Brain and heart broth is still used in path labs, but, when it comes to biopharmaceutical manufacturing, cells are having to learn to do without animal components whenever possible. This has undoubtedly been a challenge for the industry, but is leading to a better understanding of cell metabolism and physiology, which, in turn, allows cleaner and more efficient production of recombinant proteins and other biologics. 

It was Harry Eagle of the US National Institutes of Health who pioneered cell culture from the mid-1950s. The medium he devised contains all the different nutrients cells need to grow, such as amino acids, salts, vitamins and glucose. To this he added a liberal dose of horse serum, which contains various growth factors without which the cells die. Eagle's medium was an important breakthrough because a variety of cells were able to grow on it, allowing research in molecular biology to progress and eventually, in the late 1970s, to open the door to industrial cell culture and the biopharmaceutical industry. 

Foetal bovine serum (FBS) became the research and industry standard for supplementing cell culture media, but to this day, no one is quite sure what it contains. This lack of precision and certainty sits uneasily with the demands of good manufacturing practice (GMP) manufacture. So, although cells love to grow on serum, they have to be weaned off it. The BSE epidemic naturally led to concerns about the safety of medicines, such as recombinant proteins, made using bovine serum. In the UK, over 1000 people with haemophilia were infected with HIV through blood-derived Factor VIII (FVIII) treatment. Recombinant FVIII, produced by mammalian cells, is a much safer option; it would be a terrible irony if patients were put at risk again through contaminated FBS. Prions — the infectious agents causing BSE and variant CJD — are not the only potential contaminant in serum; manufacturers must also demonstrate removal of viruses, fungi, bacteria and endotoxins. 

But in fact, the trend towards serum-free cell culture dates from before BSE, and was driven primarily by concern over the cost of serum and the difficulties of obtaining a reliable supply. Moreover, unlike a chemical solvent, serum is not well-defined. Each batch is different, and must be checked and validated. Serum also causes problems in downstream processing because of its high protein content. This can overwhelm the protein product being manufactured during the purification process. That is why foetal, rather than adult, bovine serum has often been preferred for monoclonal antibody production, because foetal serum contains fewer interfering antibodies than adult bovine serum. But foetal serum is harvested from bovine foetuses taken from pregnant cows during slaughter — a procedure that raises animal welfare concerns. 

The three vital growth factors in serum are albumin, transferrin and insulin. The first steps towards serum-free media involved getting rid of the serum and providing these protein ingredients from others sources, mainly blood. Then, with the advent of the BSE crisis, it was thought the proteins ought to be replaced too, to get rid of the animal components altogether. "This proved harder than people thought it would be," says Dr Malcolm Rhodes, technical director of bioProcessUK. "Albumin provides a number of micronutrients, and helps control pH and transferrin binds iron, without which you get oxidation in the cell culture." 

Media supply companies such as Invitrogen and SAFC Biosciences have put years of development work, which is still ongoing, into this area, and there is a range of serum-free, protein-free and chemically-defined media now available for various applications. Serum-free cell culture is often used for research and may still contain proteins. If the protein comes from a recombinant source, then the medium may also be animal-free. The protein-free media could contain yeast or plant — usually wheat or soya — hydrolysates as a replacement for albumin, transferrin and insulin. These are often, but not always, free of animal components. A chemically-defined medium is totally animal-free and is, increasingly, the choice for industrial cell culture. 

Cells do not like change. If they have been growing and producing in a serum-supplemented medium, a sudden transfer to a serum-free medium will be stressful. They need to go through a gradual adaptation process. "It is not well understood what happens to the cells during this weaning process," says Dr Rhodes. "There may be genetic or epigenetic changes taking place." (An epigenetic change affects gene activity, but not gene sequence.) Cells are also more sensitive to changes in pH, osmolality, temperature, mechanical forces and enzyme action in a serum-free medium. It would appear that the protein content of a conventional medium provides the cells with some protection from these changes. Moreover, attachment-dependent cell lines require some kind of extracellular matrix, which serum seems to provide. Without it, surfaces must be coated with something the cells can attach themselves to, such as laminin or fibronectin. 

In brief, moving a cell culture from conventional to serum-, protein-, or animal-free media takes time and money, which is why some older biotech products are still manufactured with serum. The regulatory authorities will accept this — so long as the animal-derived components used in the process come from a source deemed to be safe. But new products must be as free of animal components as possible. Some manufacturers have invested in switching an established product. For instance, Baxter now makes FVIII in a albumin-free medium. 

For conventional biopharmaceuticals, the adoption of more defined media is now well underway. The challenge now is for cell therapies — where the cell itself is the product — to go animal-free. Cells destined as therapies are often grown on a layer of mouse 'feeder' cells and are, therefore, prone to viral contamination. However, Geron (a US company that plans to begin the world's first clinical trial of human embryonic stem cells later this year) has recently published methods of growing cells without the feeder layer. Many other stem cell therapy companies are now starting to develop animal-free culture technologies.  

According to SAFC Biosciences, the future of media development is towards more and more chemical definition, and will include the use of experimental tools such as RNA profiling to improve our understanding of the metabolic profile of cells during each stage of the cell cycle. "It is a hard road, but there is more potential for optimizing production if you can control individual components in a cell culture medium," argues Dr Rhodes.  

Brain and heart broth is still used in path labs, but, when it comes to biopharmaceutical manufacturing, cells are having to learn to do without animal components whenever possible.

Cell culture must go vegetarian

Biotechnology companies face some interesting technical and regulatory challenges in 2007, and beyond, in the race to bring patients a wide range of innovative products. According to a recent study from the Tufts Center for the Study of Drug Development (CSDD), the average cost of developing a new biopharmaceutical drug is around $1.2 billion. And biotech products take almost 98 months, on average, to get through clinical development and regulatory review — about 8% longer than for traditional molecule therapeutics. Therefore, there is mounting pressure on manufacturers to cut costs and speed up the production cycle.  

On the plus side, the CSDD report states that biologics have a higher clinical approval rate than conventional pharmaceuticals — 30.2%, compared with 21.5%. There are currently several hundred biotech-based drugs in clinical trials, representing around a quarter of all drugs in development — a proportion that looks set to increase.  

Besides recombinant proteins and monoclonal antibodies, there are now cell and tissue therapies, DNA vaccines, and RNAi-based products requiring GMP manufacture in clinical trial quantities. There is also increasing interest in the development of biosimilar products, following the EMEA's eventual approval of Sandoz's Omnitrop (a 'follow-on' version of recombinant human growth hormone) and Biopartners' Valtropin, a recombinant somatropin in 2006. An increasing number of biotech drugs come off patent in the next few years, so manufacturers must start thinking about producing biosimilars now.  

A couple of years ago, the prospect of this heavy and diverse 'workload' precipitated panic within the industry over cell culture capacity. Was there enough fermentation capacity to produce the hundreds of kilograms of product to serve clinical trial and commercial demand?  

The capacity crisis never really materialized, according to Avinoam Kadouri, chairman of the European Animal Cell Technology Industrial Platform. Today, the emphasis has shifted towards smarter upstream and downstream technologies, which can decrease both cost of goods and manufacturing times. "Required fermenter size will shrink, as high producing clones and cheap, simple media are developed," he predicts. "And more investment in downstream processing will mean greater recovery of product." 

For example, there is increasing emphasis upon selecting high-producing clones using technologies such as Cyntellect's LEAP (laser enabled analysis and processing), marketed by SAFC Biosciences, which allows rapid screening of millions of cells for the rare high protein producers. In the downstream area, Pall's Process Proteomics uses a microarray-based approach to optimize chromatography conditions for purification in hours, rather than the days that would be required by conventional column experiments. Such technical developments, while not yet universally adopted, can help companies achieve their goals of reducing costs and timelines.  

Manufacturers will also have to deal with the increasing shift away from bovine serum and other animal component-containing media, replacing these with synthetic media that give equivalent — or even higher — productivity in cell culture. Regulatory authorities now require companies to justify any continuing use of animal components in production processes. Companies also need to consider whether to replace some, or even all, of their stainless steel plant with plastic disposable components. Disposables score on flexibility and save on cleaning and sterilization costs, but can be a costly investment.  

Of course, the availability of manufacturing capacity is still important — whether it is based upon stainless steel or disposables — especially for academic groups and small biotechs trying to produce sufficient of their therapeutic to GMP standard to progress to proof of principle.  

There is no shortage of contract manufacturing organizations, both in Europe and, increasingly, in the Far East and India — should a company decide to outsource. And this month (January 2007) sees the opening of the UK's National Biomanufacturing Centre in Liverpool, which will help academic groups and SMEs get a foot on the manufacturing ladder. There is also a £3 million access fund, which allows for purchase of development and clinical manufacturing services at the Centre.  

Small companies need other help too and this should be forthcoming from the EMEA's new SME office, which will offer a range of incentives, including fee reductions for scientific advice and inspections and deferral of fees for an application for a marketing authorization. And on 1 January 2007, the EU introduced new state aid rules that allow Member States to provide tax breaks and other help to young innovative companies (YICs), such as small biotechs, without breaking European competition rules (at the time of publishing, it was anticipated that the EU would introduce these new state rules). The YIC status was first introduced in France and Belgium and EuropaBio has been campaigning for it to be widened to the whole of Europe for some time, according to Dr Andrea Rappagliosi, chairman of its healthcare council. 

Another top priority for EuropaBio this year is the implementation of the EU's Regulation on Advanced Therapies, which is to cover gene, cell and tissue-based therapies already on the market, or coming onto the market in the future. "This will provide a centralized European platform for regulation for the new therapies that will be developed over the next 5–10 years," says Dr Rappagliosi. The regulation will cover manufacturing and technology issues, such as risk management and traceability, although decisions on the use or nonuse of stem cells, including those from embryonic sources, will remain the responsibility of Member States. It will also include a mandatory centralized procedure for obtaining marketing approval through EMEA, and it is hoped this will support companies in developing cell and tissue therapies. 

EMEA is also developing guidelines on clinical and non-clinical aspects of biosimilar medicinal products containing a biotech-derived protein as an active substance. This is an important opportunity for companies to place greater emphasis upon process analytical technology to show to the regulatory authorities that their 'generic' version of a recombinant protein is safe, pure and effective in comparison with the original product.  

As far as the biotech business scene is concerned, Dr Kadouri predicts more competition — with a further increase in the number of companies. All the big pharmas are interested in biotech now, so watch for more developments, such as AstraZeneca's acquisition of Cambridge Antibody Technology, Novartis' purchase of NeuTec Pharma and, on the other side of the pond, Merck's acquisition of RNAi company Sirna. "In the last few years, biotechs have participated in lots of deals — collaborations, licensing, codevelopment, spin-offs and acquisitions," says Dr Rappagliosi. "These deals can only benefit biotech by helping build a critical mass and it is an integral part of how the industry is evolving. We are expecting many more such deals in 2007." 

There are currently several hundred biotech-based drugs in clinical trials, representing around a quarter of all drugs in development - a proportion that looks set to increase.