Article IVD March 2006
- 1. IN PERSON IVD Technology: What have been the biggest technological advances in assay development during the past few years? Fabrice Sultan: Assay development continues to challenge the IVD indus- try, which must bring accurate, reliable, robust, and cost-effective assays from the conceptual phase to the end-user. The use of magnetic microspheres and polymer beads as the solid phase in automated immunoassays—resulting in automation, faster reactions, increased sensitivity, and shorter time per assay— has been one of the biggest technologi- cal advances. The technical capability to develop and produce, on an industri- al scale, one bead or one microsphere for one application could explain, at least in part, the increasing demand in the field of microsphere technology. For instance, our production capabil- ities allow us to produce batches larger than 6 kg for some of our magnetic mi- crospheres used in immunoassays, and up to 12 kg for polymer beads used in immunoturbidimetric assays or latex agglutination on slides. To produce ef- ficient and reproducible immobilization of immunoglobulin or other ligands, such as proteins, lipids, or polysaccha- rides, we offer the choice of working on many different surfaces—hydrophobic or hydrophilic, carboxyl-modified, amino-modified, or thiol-modified. Different surface chemistries, of course, should be considered and evaluated in preliminary screening protocols. How- ever, the solid phase is, without a doubt, a critical and important part of the assay. How have magnetic microspheres and polymer beads contributed to the area of assay development? With ELISAs (enzyme-linked im- munosorbent assays) or with coated tubes, you can work in two dimensions. The main advantage of using magnetic or polymer microspheres is that they allow you to work in three dimensions, dramatically increasing the surface and sensitivity, and the high reaction kinetics of your assay. The evolution of assay development To keep pace with advances in detection technologies, assay manufacturers must remain resourceful. Over the last decade, automation and other technological break- throughs have revolutionized the clinical diagnostics laboratory. Driven by a demand for both higher throughput and reproducibility, as well as for lower costs per test and smaller sample size requirements, instrument manufacturers have made significant progress in alleviat- ing many former testing bottlenecks. While these advances have ultimately benefited patient care, they have also created challenges for assay manufacturers. To take advan- tage of increased laboratory capability and instrument sensitivity, as well as refinements to traditional testing methods, new assays must also continually evolve. In addition, IVD manufacturers need to forge strong relationships with customers and researchers to be able to an- ticipate the next trends in assay development, To learn more about how technology changes are affecting assay manufacturers, IVD Technology editor Richard Park spoke with Fab- rice Sultan, PhD, international marketing and sales manager at Estapor Microspheres, a division of Merck Chimie SAS (Fontenay Sous Bois, France). In this interview, Sultan discusses the impact of miniatur- ization, multiplexing, and molecular diagnostics on assays. He also talks about the state of the European testing market, and how manu- facturers can—and must—build better research relationships with academia. Fabrice Sultan, PhD, is international marketing and sales manager at Estapor Microspheres, a division of Merck Chimie SAS (Fontenay Sous Bois, France). He can be reached at fabrice.sultan@merck.fr. For In Vitro Diagnostics Development & Manufacturing R
- 2. Magnetic beads are probably the most powerful tools for IVD manufacturers looking to automate their immunoassays because many types of proteins and lig- ands can be easily attached to their sur- faces. And the surface for the reaction mixture is much higher than with clas- sical ELISA plates or coated tubes. What factors must IVD manufactur- ers consider when developing assays for their instrument systems? When developing immunoassays, IVD manufacturers must consider not only the accuracy and reproducibility of a new immunoassay reagent, but also its stability and ease of adaptation. We must consider two types of stabil- ity. The classical stability of the reagent in the cartridge should be around 12–18 months. And once the cartridge is opened, the reagent stability should be at least one or two months. You can validate a product if you ob- tain the same reproducibility results. However, some immunoassay reagents have a very short stability once the car- tridge is opened. If a reagent has a shelf life of 20 or 24 months when the cartridge is closed, but only two weeks once it is opened, it can be very difficult to sell. What other assay development trends do you see? The latest trends are geared toward achieving classical, common goals: sen- sitivity and signal-to-noise ratio. Both must be higher than they are now. Specificity of an immunoassay must be better. The dynamic range must be increased, especially if you want to de- tect a very low concentration of analyte. Any assay technology that enables the end-user to eliminate, or at least reduce, the number of false-positive results is always extremely advantageous. Also, the cost of the assay must be lower, to answer the economic pressures on both IVD companies and clinical labs, and also on patients. From several studies, we know that labor accounts for 50–70% of the total cost of tests. The most logical way to re- duce this cost is the automation of com- mon bioassays and immunoassays. Of course, new automated tests can also show better results than semiautomated or manual ones. How can IVD manufacturers address these challenges? A complete market survey is essential before IVD manufacturers begin de- signing and developing a new assay product. Of course, a company’s strate- gy will be different for a me-too product than for a truly innovative one. For the first, cost and services are the keys to success. For the second, manufacturers need to answer the following questions: What is the clinical utility of this new assay? What is the test volume? What are the sales by geographic region and the total profits? What market share do I want to reach? What could be the pos- sible alternative with a new technology in the near future? IVD companies must be faster than ever and provide a broad menu of diag- nostic tests. Time to market should be re- duced to a minimum. It’s very easy now for some big IVD companies to exter- nalize part of their R&D to launch new assays in a shorter period. But the chal- lenge will be to keep the production internal. I can see two main options. IVD com- panies can employ their own staff and capabilities, or they can accomplish this through codevelopment with other com- panies or with universities. Any type of collaboration must be a win-win agree- ment. For example, large companies can offer name recognition and a worldwide sales force or distribution network, which are both key advantages for small IVD companies. And small IVD com- panies can offer increased flexibility, more freedom, and access to intellectu- al property. There have been a number of these types of collaborations. For example, Roche Diagnostics (Basel, Switzerland) and Prionics AG (Schlieren, Switzer- land) have worked together on a test for bovine spongiform encephalopathy. Beckman Coulter Inc. (Fullerton, CA) and R&D Systems (Minneapolis) have signed an agreement for developing as- says and assay components for Beck- man Coulter’s Access immunoassay systems. To secure sources of critical raw ma- terial—both in quality and quantity— IVD manufacturers should evaluate and validate two possible suppliers: one main supplier, and a secondary supplier for the solid phase, the antibodies, or the antigen. Of course, for some companies, secondary antibodies and substrate sup- plies must be secure, too. We know that the cost to validate each critical raw material is very high. But this is critical for IVD manufacturers. For security reasons, many IVD compa- nies now produce their own antibodies or antigens. And some of them have their own solid-phase production. Of course, doing so is much more secure, but at what cost? Do you expect IVD manufacturers to continue forming these types of collaborations? Oh, yes. I can add to my examples others like the ongoing partnership be- tween Abbott (Abbott Park, IL) and Axis-Shield Plc (Dundee, UK), as well as the collaboration between Dade Behring Inc. (Deerfield, IL) and The Binding Site Ltd. (Birmingham, UK). Merck partners with academics in order to develop new magnetic particles and polymer beads. We are always work- ing with our customers to optimize our products with their immunoassay reagents. Partnering with Academia How important is it for IVD and di- agnostics component manufacturers to form relationships with academic researchers to develop assays? It’s fundamental to have an excellent network between IVD manufacturers, academic researchers, and hospital or blood bank centers. From our viewpoint, the majority of IVD manufacturers have been working with academic researchers in developing assays. Many new bio- markers, like NT-proBNP, which has a clinical utility for acute coronary syn- drome, have been discovered by acade- mic researchers. And after this research has been conducted, diagnostics compa- IN PERSON
- 3. nies have the opportunity to add new im- munoassay reagents to their test menu. One possibility for IVD manufactur- ers is to establish, or even share, scien- tific laboratories. For example, in France there are a number of Unités Mixtes de Recherches, or joint research units, which are very efficient scientific col- lectives between IVD companies like bioMérieux or Bio-Rad France and well-known scientific institutes like the CNRS (French Center for Scientific Research). Such collaborations can increase the possibility of finding new biomarkers or developing new immunoassays. How do IVD manufacturers go about developing and nurturing these rela- tionships with academia? There are a few different ways. A company can sign financial agreements with academic researchers—to develop a new immunoassay on a new biomark- er, for example. Companies can also as- sist researchers with grants or fellow- ships. And again, I think having IVD staff share the scientific laboratory with scientific researchers is very important. These scientists spend two to four years in our lab working directly with our R&D department. This is a very common arrangement in France. We share the results of the research with the university. It is the case in France, as I’m sure it is in the rest of the world, that researchers lack money. As a result, they need to find new ways to obtain financing to contin- ue their scientific work. The sense that I get when speaking with academic scientists is that they are always seeking out industry partnerships to commercialize their projects. Yes. I think that the development of a new immunoassay can be viewed as a two-step process. The first step involves academics in the discovery of new bio- markers with clinical utility. And after some years—because it’s a long process—it might be possible for a company to use the results of this re- search to develop its own immunoassay reagent. Adopting Molecular Diagnostics How have developments in molecular diagnostics and pharmacogenomics affected assay development? In my opinion, diagnostics develop- ments using the polymerase chain reac- tion (PCR) and related methods will have an impact primarily in the field of infectious diseases. Immunoassays for detecting HIV or a specific antigen can easily be created by using classical methods. More and more molecular diagnostic reagents have come onto the market in recent years. Instead of detecting an an- tibody or antigen, these types of tests bind the nucleic acids from the cells and amplify them through PCR or a similar method. The infectious disease is then detected and computed using the con- tent of nucleic acid. But for cardiac markers, en- docrinology, drugs of abuse, or fertili- ty tests, molec-ular diagnostics is not having much of an effect on assay de- velopment. These are sophisticated methods. Of course, they are already being used by many hospitals. But I cannot think of any IVD manufacturers that are poised to offer a large menu of assays that use this kind of technical approach. In March of last year, some of the foundational PCR patents, which are owned by Roche Diagnostics, began to expire. As additional Roche PCR patents enter the public domain, do you think more IVD companies will embrace molecular diagnostics? Probably, yes, because one limit so far to developing such assays has been cost. If you have to pay for the develop- ment and the production, and the mar- keting and the sales of such reagents— and then you also have to pay for the patent—in the end, profits will be very low. And if the profit is low, many com- panies might not consider the assays to be wise investments. But with the disappearance of fees for PCR use, we probably will see more and more molecular diagnostic reagents and instruments coming onto the market in the next few years. How about further into the future? Do you think that these technologies will have more of an impact as they mature? Say, in 10 years from now? In the next decade, we will likely see many IVD manufacturers working with multiplexing assays, quantitative lateral- flow assays, biochips, biosensors, and mi- crofluidics. We will also see important developments in the point-of-care field. The Next Generation of IVDs What future assay development chal- lenges do you anticipate facing? Miniaturization of immunoassays is a major goal in medical diagnostics, but also in food and environmental analysis. There is an important need for multiplex analyses with three main char- acteristics: a high degree of automation, fast analysis, and a small volume of sample reagents. Will IVD manufacturers in the assay market become more involved with nanotechnology and microarrays? Yes, I think so. There’s been a lot of cooperation in these areas between big IVD companies working on classical immunoassay instruments and some new players in this field. In nanotech- nology, there have been collaborations regarding biochips and biosensors, as well as microfluidics. The business managers at large diag- nostics companies have to keep an eye on these new technologies because they may prove to be a very efficient way to reduce the costs of analysis. For exam- ple, instead of using 10 or 20 ml of blood to detect the HIV or hepatitis virus, in the next few years, we may need only a few microliters. And if the sample is a few microliters, we will also need only a few microliters of reagent. What trends can we expect to see with the use of magnetic microspheres and polymer beads in assay development? We are continuing to develop both magnetic and polymer beads with new surfaces in order to allow developers to optimize and obtain the best reagents. But we are also working on new types of beads,suchasthoseusingmolecularprint. With molecular printing, instead of using an antibody or an antigen cut onto the
- 4. beads to detect the corresponding ana- lytes, the structure of the antibody or the antigen is printed on the bead surface. This could be interesting in several re- spects: cost, certainly, but also regarding issues like stability and reproducibility. How has the emergence of biodefense and bioterrorism concerns affected assay development? From a technical standpoint, neither biodefense nor bioterrorism has really affected assay development. To detect biodefense or bioterrorism agents, we currently use classical testing methods such as lateral-flow and ELISA. In fact, these same tools are used for pregnancy or C-reactive protein tests. However, there is an urgency to offer these types of diagnostics. For this reason, it is important for the industry to cooperate more with academia in order to speed the development of such tests. This is how biodefense and bioterror- ism concerns could affect assay devel- opment—by encouraging more cooper- ation and by reducing the time to develop and to market such important tests. Is there still interest in developing faster and more-extensive tests? Sure. In creating diagnostics for biode- fense and bioterrorism agents, we need to think about who will use these tests. And you’re right. There is a need to develop simple tests that can be used in the field and are able to detect agents directly. Simplicity is the most important as- pect. Of course, if you want to detect biodefense and bioterrorism agents in rich countries, you can use more- sophisticated methods like immuno- assays or ELISA, or perhaps even chromatography. What is the current attitude in Europe toward developing biodefense and bioterrorism diagnostics? The development of these assays is done mainly by military scientists. In some instances, military scientists have collaborated with big institutes like the Commissariat à l’Énergie Atomique (Atomic Energy Commission) in France. But there hasn’t been as much activity in this area in Europe as in the United States. How would you characterize the cur- rent state of the European IVD mar- ket in general? The European market for IVDs is more or less the same as what you see in the United States. For one, a lot of diag- nostics companies that sell their prod- ucts in Europe are from the United States. For this reason, we are more or less using the same instruments, the same reagents, and the same kits. Perhaps there are a few differences regarding the use of rapid tests. Rapid tests are not very common today in France due to regulatory reasons. But I think that these regulations will change and that physicians will be allowed, in the next few years, to use these tests in a number of applications—for the de- tection of infectious diseases or cancer markers, for example. Speaking of regulations, it’s been two years since the IVD Directive went into effect throughout the European Union. How has it affected the IVD market there? The purpose of the IVD Directive is to ensure that only safe and functional bioproducts are sold in the European market, with clearly outlined regulations regarding manufacturing, importing, and marketing. However, the directives combine advantages and disadvantages and could affect small and large IVD companies differently. Companies complying with these reg- ulations will gain better access to more geographic markets—the 25 European Union member states and the four Eu- ropean Free Trade Association members (Switzerland, Iceland, Norway, and Liechtenstein). This market represents more than €9 billion. The disadvantages of the IVD Direc- tive are that it requires more adminis- trative work—such as translation, pa- perwork, registration, and approvals —and can delay product introduction into the commercial market, and that it increases the cost of the products. That said, the directives ensure high-quality products for all patients. The challenge for European IVD companies is not so much to create accurate, reliable, or ro- bust assays, but rather to stay competi- tive and develop cost-effective assays— not only for the European market but worldwide. Reprinted from IVD Technology, March 2006 • Copyright © 2006 Canon Communications LLC IN PERSON The latest trends in development are geared toward achieving classical, common goals.