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Gene editing battles

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Competition is intensifying among scientists to develop and use gene editing and immunotherapy to defeat intractable diseases
Chinese scientists were the first to inject people with cells modified by the CRISPR–Cas9 gene-editing technique
Several studies have extracted a patient’s own immune cells, modified them using gene-editing techniques, and re-infused them into the patient to seek and destroy cancer cells
A new prêt à l'emploi gene editing treatment disables the gene that causes donor immune cells to attack their host
The technique harvests immune cells from a donor, modifies and multiplies them so that they may be used quickly, easily and cheaply on different patients
Commercial, technical, regulatory and ethical barriers to gene editing differ in different geographies

Gene editing battles

Gene editing and immunotherapy are developing at a pace. They have been innovative and effective in the fight against melanoma, lung cancer, lymphomas and some leukaemias, and promise much more. Somatic gene therapy changes, fixes and replaces genes at the tissue or cellular levels to treat a patient, and the changes are not passed on to the patient’s offspring. Germ line gene therapy inserts genes into reproductive cells and embryos to correct genetic defects that could be passed on to future generations. Although there are still many unanswered clinical, commercial and ethical questions surrounding gene therapy, its future is assured and will be shaped by unexpected new market entrants and competition between Chinese and Western scientists, which is gaining momentum.

14 February 2017

On the 14^th February 2017 an influential US science advisory group formed by the National Academy of Sciences and the National Academy of Medicine gave support to the modification of human embryos to prevent “serious diseases and disabilities” in cases where there are no other “reasonable alternatives”. This is one step closer to making the once unthinkable heritable changes in the human genome. The Report, however, insisted that before humanity intervenes in its own evolution, there should be a wide-ranging public debate, since the technology is associated with a number of unresolved ethical challenges. The French oppose gene editing, the Dutch and the Swedes support it, and a recent Nature editorial suggested that the EU is, “habitually paralysed whenever genetic modification is discussed”. In the meantime, clinical studies, which involve gene-editing are advancing at a pace in China, while the rest of the world appears to be embroiled in intellectual property and ethical debates, and playing catch-up.

15 February 2017

On the 15^th February 2017, after a long, high-profile, heated and costly intellectual property action, judges at the US Patent and Trademark Office ruled in favor of Professor Feng Zhang and the Broad Institute of MIT and Harvard, over patents issued to them associated with the ownership of the gene-editing technology CRISPR-Cas9: a cheap and easy-to-use, all-purpose gene-editing tool, with huge therapeutic and commercial potential.

The proceedings were brought by University College Berkeley who claimed that the CRISPR technology had been invented by Professor Jennifer Doudna of the University, and Professor Emmanuelle Charpentier, now at the Max Planck Institute for Infection Biology in Berlin, and described in a paper they published in the journal Science in 2012. Berkeley argued that after the 2012 publication, an “obvious” development of the technology was to edit eukaryotic cells, which Berkeley claimed is all that Zhang did, and therefore his patents are without merit.

The Broad Institute countered, suggesting that Zhang made a significant inventive leap in applying CRISPR knowledge to edit complex organisms such as human cells, that there was no overlap with the University of California’s research outcomes, and that the patents were therefore deserved. The judges agreed, and ruled that the 10 CRISPR-Cas9 patents awarded to Zhang and the Broad Institute are sufficiently different from patents applied for by Berkeley, so that they can stand.

The scientific community

Interestingly, before the 15th February 2017 ruling, the scientific community had appeared to side with Berkeley. In 2015 Doudna, and Charpentier were awarded US$3m and US$0.5m respectively for the prestigious Breakthrough Prize in life sciences and the Gruber Genetics Prize. In 2017 they were awarded the Japan Prize of US$0.45m for, “extending the boundaries of life sciences”. Doudna and Charpentier have each founded companies to commercially exploit their discovery: respectively Intellia Therapeutic, and CRISPR Therapeutics.

16 February 2017

A day after the patent ruling, Doudna said: “The Broad Institute is happy that their patent didn’t get thrown out, but we are pleased that our patent based on earlier work can now proceed to be issued”. According to Doudna, her patents are applicable to all cells, whereas Zhang’s patents are much more narrowly indicated. “They (Zhang and the Broad Institute) will have patents on green tennis balls. We will get patents on all tennis balls,” says Doudna.

Gene biology

Gene therapy has evolved from the science of genetics, which is an understanding of how heredity works. According to scientists life begins in a cell that is the basic building block of all multicellular organisms, which are made up of trillions of cells, each performing a specific function. Pairs of chromosomes comprising a single molecule of DNA reside in a cell’s nucleus. These contain the blueprint of life: genes, which determine inherited characteristics. Each gene has millions of sequences organised into segments of the chromosome and DNA. These contain hereditary information, which determine an organism’s growth and characteristics, and genes produce proteins that are responsible for most of the body’s chemical functions and biological reactions.

Roger Kornberg, an American structural biologist who won the 2006 Nobel Prize in Chemistry "for his studies of the molecular basis of eukaryotic transcription", describes the Impact of human genome determination on pharmaceuticals:

China’s first

While American scientists were fighting over intellectual property associated with CRISPR-Cas9, and American national scientific and medical academies were making lukewarm pronouncements about gene editing, Chinese scientists had edited the genomes of human embryos in an attempt to modify the gene responsible for β-thalassemia and HIV, and are planning further clinical studies. In October 2016, Nature reported that a team of scientists, led by oncologist Lu You, at Ghengdu’s Sichuan University in China established a world first by using CRISPR-Cas9 technology to genetically modify a human patient’s immune cells, and re-infused them into the patient with aggressive lung cancer, with the expectation that the edited cells would seek, attack and destroy the cancer. Lu is recruiting more lung cancer patients to treat in this way, and he is planning further clinical studies that use similar ex vivo CRISPR-Cas9 approaches to treat bladder, kidney and prostate cancers

The Parker Institute for Cancer Immunotherapy

Conscious of the Chinese scientists’ achievements, Carl June, Professor of Pathology and Laboratory Medicine at the University of Pennsylvania and director of the new Parker Institute for Cancer Immunotherapy, believes America has the scientific infrastructure and support to accelerate gene editing and immunotherapies. Gene editing was first used therapeutically in humans at the University of Pennsylvania in 2014, when scientists modified the CCR5 gene (a co-receptor for HIV entry) on T-cells, which were injected in patients with AIDS to tackle HIV replication. Twelve patients with chronic HIV infection received autologous cells carrying a modified CCR5 gene, and HIV DNA levels were decreased in most patients.

Medical science and the music industry

The Parker Institute was founded in 2016 with a US$250m donation from Sean Parker, founder of Napster, an online music site, and former chairman of Facebook. This represents the largest single contribution ever made to the field of immunotherapy. The Institute unites 6 American medical schools and cancer centres with the aim of accelerating cures for cancer through immunotherapy approaches.

Parker, who is 37, believes that medical research could learn from the music industry, which has been transformed by music sharing services such as Spotify. According to Parker, more scientists sharing intellectual property might transform immunotherapy research. He also suggests that T-cells, which have had significant success as a treatment for leukaemia, are similar to computers because they can be re-programed to become more effective at fighting certain cancers. The studies proposed by June and colleagues focus on removing T-cells, from a patient’s blood, modifying them in a laboratory to express chemeric antigen receptors that will attack cancer cells, and then re-infusing them into the patient to destroy cancer. This approach, however, is expensive, and in very young children it is not always possible to extract enough immune cells for the technique to work.

Prêt à l'emploi therapy

Waseem Qasim, Professor of Cell & Gene Therapy at University College London and Consultant in Paediatric immunology at Great Ormond Street Hospital, has overcome some of the challenges raised by June and his research. In 2015 Qasim and his team successfully used a prêt à l'emploi gene editing technique on a very young leukaemia patient. The technique, developed by the Paris-based pharmaceutical company Cellectis, disables the gene that causes donor-immune cells to attack their host. This was a world-first to treat leukaemia with genetically engineered immune cells from another person. Today, the young leukaemia patient is in remission. A second child, treated similarly by Qasim in December 2015, also shows no signs of the leukaemia returning. The cases were reported in 2017 in the journal Science Translational Medicine.

Universal cells to treat anyone cost effectively

The principal attraction of the prêt à l'emploi gene editing technique is that it can be used to create batches of cells to treat anyone. Blood is collected from a donor, and then turned into “hundreds” of doses that can then be stored frozen. At a later point in time the modified cells can be taken out of storage, and easily re-infused into different patients to become exemplars of a new generation of “living drugs” that seek and destroy specific cancer cells. The cost to manufacture a batch of prêt à l'emploi cells is estimated to be about US$4,000 compared to some US$50,000 using the more conventional method of altering a patient’s cells and returning them to the same patient. Qasim’s clinical successes raise the possibility of relatively cheap cellular therapy using supplies of universal cells that could be dripped into patients' veins on a moment’s notice.

Takeaways

CRISPR-Cas9 provides a relatively cheap and easy-to-use means to get an all-purpose gene-editing technology into clinics throughout the world. Clinical studies using the technology have shown a lot of promise especially in blood cancers. These studies are accelerating, and prêt à l'emploi gene editing techniques as an immunotherapy suggest a new and efficacious therapeutic pathway. Notwithstanding the clinical successes, there remain significant clinical, commercial and ethical challenges, but expect these to be approached differently in different parts of the world. And expect these differences to impact on the outcome of the scientific race, which is gaining momentum.

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The convergence of MedTech and pharma and the role of biosensors

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implantable biosensor device

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sensing technology

The convergence of MedTech and pharma can generate innovative combination devices that promise significant therapeutic and commercial benefits
Combination devices such as advanced drug delivery systems offer more precise, predictable and personalized healthcare
The global market for advanced drug delivery systems is US$196bn and growing
Biosensors play a role in convergence and innovative drug delivery systems
Roger Kornberg, Professor of Medicine at Stanford University and 2006 Nobel Prize winner for Chemistry describes the technological advances, which are shaping new medical therapies

The convergence of MedTech and pharma and the role of biosensors

MedTech and pharma companies are converging.
What role do biosensors play in such a convergence?

Traditionally, MedTech and big pharma have progressed along parallel paths. More recently, however, their paths have begun to converge in an attempt to gain a competitive edge in a radically changing healthcare landscape. Convergence leverages MedTech’s technical expertise and pharma’s medical and biological agents to develop combination devices. These are expected to significantly improve diagnosis, monitoring and treatment of 21^st century chronic lifetime diseases, and thereby make a substantial contribution to an evolving healthcare ecosystem that demands enhanced patient outcomes, and effective cost-containment.

Conventional diagnostics & drug delivery

Conventional in vitro diagnostics for common diseases are costly, time-consuming, and require centralized laboratories, experienced personnel and bulky equipment. Standard processes include the collection and transportation of biological samples from the point of care to a centralized laboratory for processing by experienced personnel. After the results become available, which usually takes days, the laboratory notifies doctors, who in turn contact patients, and modify their treatments as required. Conventional modes of treatment have mainly consisted of simple, fast-acting pharmaceuticals dispensed orally or as injectables. Such limited means of drug delivery slows the progress of drug development since most drugs are formulated to accommodate the conventional oral or injection delivery routes. Concerns about the quantity and duration of a drug’s presence, and its potential toxic effect on proximal non-diseased tissue drives interest in alternative drug delivery systems and fuels the convergence of MedTech and pharma.

The end of in vitro diagnostics

Roger Kornberg, Professor of Medicine at Stanford University, reflects on the limitations of conventional in vitro diagnostics, and describes how technological advances facilitate rapid point-of-care diagnostics, which are easier and cheaper:

Converging interest

Illustrative of the MedTech-pharma convergence is Verily's (formerly Google Life Sciences) partnership with Novartis to develop smart contact lenses to correct presbyopia, (age-related farsightedness), and for monitoring diabetes by measuring glucose in tears. Otsuka’s, partnership with Proteus Digital Health is another example. This venture expects to develop an ingestible drug adherence device. Proteus already has a FDA-approved sensor, which measures medication adherence. Otsuka is embedding the Proteus’s sensor, which is the size of a sand particle, into its medication for severe mental illnesses in order to enhance drug adherence, which is a serious problem. 50% of prescribed medication in the US is not taken as directed, resulting in unnecessary escalation of conditions and therapies, higher costs to health systems, and a serious challenge for clinical studies.

Drivers of change

The principal drivers of MedTech-pharma convergence include scientific and technological advances, ageing populations, increased chronic lifestyle diseases, emerging-market expansion, and developments in therapies. All have played a role in changing healthcare demands and delivery landscapes. Responding to these changes, both MedTech and pharma have continued to emphasize growth, while attempting to enhance value for payers and patients. This has resulted in cost cutting, and a sharper focus on high-performing therapeutics. It has also fuelled MedTech-pharma convergence and the consequent development of combination devices. According to Deloitte’s 2016 Global Life Science Outlook, combination devices “will likely continue to rapidly increase in number and application”.

MedTech’s changing business model

Over the past two decades, MedTech has been challenged by tighter regulatory scrutiny, and continued pressure on healthcare budgets, but advantaged by technological progress, which it has embraced to create new business models. This has been rewarded by positive healthcare investment trends. Over a similar period, pharma has been challenged by the expiry of its patents, advances in molecular science, and changing demographics, but buoyed by increased healthcare spending trends, although the forces that increase health costs are being tempered by a demand for value.

As pharma has been increasingly challenged, so interest has increased in the potential of MedTech to address some of the more pressing healthcare demands in a radically changing healthcare ecosystem. Unlike pharma, MedTech has leveraged social, mobile, and cloud technologies to develop new business models and innovative devices for earlier diagnoses, faster and less invasive interventions, enhanced patient monitoring, and improved management of lifetime chronic conditions.

Such innovations are contributing to cheaper, faster, and more efficient patient care, and shifting MedTech’s strategic focus away from curative care, such as joint replacements, to improving the quality of life for patients with chronic long-term conditions. This re-focusing of its strategy has strengthened MedTech commercially, and is rapidly changing the way in which healthcare is delivered, the way health professionals treat patients, and the way patients’ experience healthcare.

Josh Shachar, founder of several successful US technology companies and author of a number of patents, describes the new healthcare ecosystem and some of the commercial opportunities it offers, which are predicated on the convergence of MedTech and pharma:

The decline of big pharma’s traditional business model

Pharma’s one-size-fits-all traditional business model, which has fuelled its commercial success over the past century, is based on broad population averages. This now is in decline as patents expire on major drugs, and product pipelines diminish. For example, over the past 30 years the expiry of pharma’s patents cost the industry some US$240bn.

Advances in genetics and molecular biology, which followed the complete sequencing of the human genome in 2003, revolutionized medicine and shifted its focus from inefficient one-size-fits-all drugs to personalized therapies that matched patients to drugs via diagnostic tests and biomarkers in order to improve outcomes, and reduce side effects. Already 40% of drugs in development are personalized medicines, and this is projected to increase to nearly 70% over the next five years.

Today, analysts transform individuals’ DNA information into practical data, which drives drug discovery and diagnostics, and tailors medicines to treat individual diseases. This personalized medicine aims to target the right therapy to the right patient at the right time, in order to improve outcomes and reduce costs, and is transforming how healthcare is delivered and diseases managed.

Personalized medicine

Personalized medicine has significantly dented pharma’s one-size-fits-all strategies. In general, pharma has been slow to respond to external shocks, and slow to renew its internal processes of discovery and development. As a result, the majority of new pharma drugs only offer marginal benefits. Today, pharma finds itself trapped in a downward commercial spiral: its revenues have plummeted, it has shed thousands of jobs, it has a dearth of one-size-fits-all drugs, and its replacement drugs are difficult-to-find, and when they are, they are too expensive.

Illustrative of the advances in molecular science that helped to destroy pharma’s traditional commercial strategy is the work of Kornberg. Here he describes an aspect of his work that is related to how biological information encoded in the genome is accessed to inform the direction of all human activity and the construction of organisms for which Kornberg received the Nobel Prize in Chemistry 2006, and created the foundations of personalized medicine:

Advanced drug delivery systems

Over the past 20 years, as pharma has struggled commercially and MedTech has shifted its business model, drug delivery systems have advanced significantly. Evolving sensor technologies have played a role in facilitating some of these advances, and are positioned to play an increasingly important role in the future of advanced drug delivery. According to BCC Research, the global market for advanced drug delivery systems, which increase bioavailability, reduce side effects, and improve patient compliance, increased from US$134bn in 2008 to some US$196bn in 2014.

The growth drivers for innovative drug delivery systems include recent advances of biological drugs such as proteins and nucleic acids, which have broadened the scope of therapeutic targets for a number of diseases. There are however, challenges.

Proteins are important structural and functional biomolecules that are a major part of every cell in your body. There are two nucleic acids: DNA and RNA. DNA stores and transfers genetic information, while RNA delivers information from DNA to protein-builders in the cells.

For instance, RNA is inherently unstable, and potentially immunogenic, and therefore requires innovative, targeted delivery systems. Such systems have benefitted significantly from progress in biomedical engineering and sensor technologies, which have enhanced the value of discoveries of bioactive molecules and gene therapies, and contributed to a number of new, advanced and innovative combination drug delivery systems, which promise to be more efficacious than conventional ones.

Biosensors

The use of biosensors in drug delivery system is not new. The insulin pump is one example. Introduced in its present form some 30 years ago, the insulin pump is a near-physiologic programmable method of insulin delivery that is flexible and lifestyle-friendly.

Biosensors are analytical tools, which convert biological responses into electrical signals. In healthcare, they provide analyses of chemical or physiological processes and transmit that physiologic data to an observer or to a monitoring device. Historically, data outputs generated from these devices were either analog in nature or aggregated in a fashion that was not conducive to secondary analysis. The latest biosensors are wearable and provide vital sign monitoring of patients, athletes, premature infants, children, psychiatric patients, people who need long-term care, elderly, and people in remote regions.

Increased accuracy and speed

The success of biosensors is associated with their ability to achieve very high levels of precision in measuring disease specific biomarkers both in vitro and in vivo environments. They use a biological element, such as enzymes, antibodies, receptors, tissues and microorganisms capable of recognizing or signalling real time biochemical changes in different inflammatory diseases and tumors. A transducer is then used to convert the biochemical signal into a quantifiable signal that can be transmitted, detected and analysed, and thereby has the potential, among other things, for rapid, accurate diagnosis and disease management.

Recent technological advances have led to the development of biosensors capable of detecting the target molecule in very low quantities and are considered to have enhanced capacity for increased accuracy and speed of diagnosis, prognosis and disease management. Biosensors are robust, inexpensive, easy to use, and more importantly, they do not require any sample preparation since they are able to detect almost any biomarker - protein, nucleic acid, small molecule, etc. - within a pool of other bimolecular substances. Recently, researchers have developed various innovative strategies to miniaturize biosensors so that they can be used as an active integral part of tissue engineering systems and implanted in vivo.

Market for biosensors

Over the past decade, the market in biosensors and bioinformatics has grown; driven by advances in artificial intelligence (AI), increased computer power, enhanced network connectivity, miniaturization, and large data storage capacity.

Today, biosensors represent a rapidly expanding field estimated to be growing at 60% per year, albeit from a low start. In addition to providing a critical analytical component for new drug delivery systems, biosensors are used for environmental and food analysis, and production monitoring. The estimated annual world analytical market is about US$12bn, of which 30% is in healthcare. There is a vast market expansion potential for biosensors because less than 0.1% of the analytical market is currently using them.

A significant impetus of this growth comes from the healthcare industry, where there is increasing demand for inexpensive and reliable sensors across many aspects of both primary and secondary healthcare. It is reasonable to assume that a major biosensor market will be where an immediate assay is required, and in the near-term patients will use biosensors to monitor and manage treatable lifetime conditions, such as diabetes cancer, and heart disease.

The integration of biosensors with drug delivery

The integration of biosensors with drug delivery systems supports improved disease management, and better patient compliance since all information in respect to a person’s medical condition may be monitored and maintained continuously. It also increases the potential for implantable pharmacies, which can operate as closed loop systems that facilitate continuous diagnosis, treatment and prognosis without vast data processing and specialist intervention. A number of diseases require continuous monitoring for effective management. For example, frequent measurement of blood flow changes could improve the ability of health care providers to diagnose and treat patients with vascular conditions, such as those associated with diabetes and high blood pressure. Further, physicochemical changes in the body can indicate the progression of a disease before it manifests itself, and early detection of illness and its progression can increase the efficacy of therapeutics.

Takeaways

Combination devices, which are triggered by the convergence of MedTech and pharma, offer substantial therapeutic and commercial opportunities. There is significant potential for biosensors in this convergence. The importance of biosensors is associated with their operational simplicity, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated into different functions using the same chip. However, there remain non-trivial challenges to reconcile the demands of performance and yield to simplicity and affordability.

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Gene editing positioned to revolutionise medicine

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Chinese scientists lead the world in editing genomes of human embryos in order to develop new therapies for intractable diseases
US and UK regulators have given permission to edit the genes of human embryos
CRISPR-Cas9 has become the most common gene editing platform, which acts like is a pair of molecular scissors
CRISPR technology has the potential to revolutionize medicine, but critics say it could create a two-tiered society with elite citizens, and an underclass and have called for a worldwide moratorium on gene editing
Roger Kornberg, professor of medicine at Stanford University and 2006 Nobel Prize winner for Chemistry explains the science, which underpins gene-editing technology

Gene editing positioned to revolutionise medicine

It is a world first for China.

In 2015, a group of Chinese scientists edited the genomes of human embryos in an attempt to modify the gene responsible for β-thalassemia, a potentially fatal blood disorder. Researchers, led by Junjiu Huang from Sun Yat-sen University in Guangzhou, published their findings in the journal Protein & Cell.

In April 2016, another team of Chinese scientists reported a second experiment, which used the same gene editing procedure to alter a gene associated with resistance to the HIV virus. The research, led by Yong Fan, from Guangzhou Medical University, was published in the Journal of Assisted Reproduction and Genetics. At least two other groups in China are pursuing gene-editing research in human embryos, and thousands of scientists throughout the world are increasingly using a gene-editing technique called CRISPR-Cas9.

CRISPR-Cas9

Almost all cells in any living organism contain DNA, a type of molecule, which is passed on from one generation to the next. The genome is the entire sequence of DNA or an organism. Gene editing is the deliberate alteration of a selected DNA sequence in a living cell. CRISPR-Cas9 is a cheap and powerful technology that makes it possible to precisely “cut and paste” DNA, and has become the most common tool to create genetically modified organisms. Using CRISPR-Cas9, scientists can target specific sections of DNA, delete them, and if necessary, insert new genetic sequences. In its most basic form, CRISPR-Cas9 consists of a small piece of RNA, a genetic molecule closely related to DNA, and an enzyme protein called Cas9. The CRISPR component is the programmable molecular machinery that aligns the gene-editing tool at exactly the correct position on the DNA molecule. Then Cas9, a bacterial enzyme, cuts through the strands of DNA like a pair of molecular scissors. Gene editing differs from gene therapy, which is the introduction of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.

Ground-breaking discovery

The ground-breaking discovery of how CRISPR-Cas9 could be used in genome editing was first described by Jennifer Doudna, Professor of Chemistry and Cell Biology at the University of California, Berkeley, and Emmanuelle Charpentier, a geneticist and microbiologist, now at the Max Plank Institute for Infections in Berlin, and published in the journal Science in 2012.

In 2011 Feng Zhang, a bioengineer at the Broad Institute, MIT and Harvard, learned about CRISPR and began to work adapting CRISPR for use in human cells. His findings were published in 2013, and demonstrated how CRISPR-Cas9 can be used to edit the human genome in living cells.

Subsequently, there has been a battle, which is on-going, between the scientists and their respective institution over the actual discovery of CRISPR’s use in human embryos, and who is entitled to the technology’s patents.

Gene editing research gathers pace worldwide: a few western examples

In 2016 a US federal biosafety and ethics panel licensed scientists at the University of Pennsylvania’s new Parker Institute of Cancer Immunotherapy to undertake the first human study to endow T-cells with the ability to attack specific cancers. Patients in the study will become the first people in the world to be treated with T-cells that have been genetically modified.

T-cells are designed to fight disease, but puzzlingly they are almost useless at fighting cancer. Carl June, the Parker Institute’s director and his team of researchers, will alter three genes in the T-cells of 18 cancer patients, essentially transforming the cells into super fighters. The patients will then be re-infused with the cancer-fighting T-cells to see if they will seek and destroy cancerous tumors.

Also in 2016, the UK’s Human Fertilisation and Embryology Authority (HFEA), which regulates fertility clinics and research, granted permission to a team of scientists led by Kathy Niakan at the Francis Crick Institute in London to edit the genes of human IVF embryos in order to investigate the causes of miscarriage. Out of every 100 fertilized eggs, fewer than 50 reach the early blastocyst stage, 25 implant into the womb, and only 13 develop beyond three months.

Frederick Lander, a development biologist at the Karolinska Institute Stockholm, is also using gene editing in an endeavour to discover new ways to treat infertility and prevent miscarriages. Lander is the first researcher to modify the DNA of healthy human embryos in order to learn more about how the genes regulate early embryonic development. Lander, like other scientists using gene-editing techniques on human embryos, is meticulous in not allowing them to result in a live birth. Lander only studies the modified embryos for the first seven days of their growth, and he never lets them develop past 14 days. “The potential benefits could be enormous”, he says.

Gene editing cures in a single treatment

Doctors at IVF clinics can already test embryos for genetic diseases, and pick the healthiest ones to implant into women. An advantage of gene editing is that potentially it could be used to correct genetic faults in embryos instead of picking those that happen to be healthy. This is why the two Chinese research papers represent a significant turning point. The gene editing technology they used has the potential to revolutionize the whole fight against devastating diseases, and to do many other things besides. The main benefit of gene editing therapy is that it provides potential cures for intractable diseases with a single treatment, rather than multiple treatments with possible side-effects.

The promise of gene editing for fatal and debilitating diseases

Among other things, gene editing holds out promise for people with fatal or debilitating inherited diseases. There are over 4,000 known inherited single gene conditions, affecting about 1% of births worldwide. These include the following:- cystic fibrosis, which each year affects about 70,000 people worldwide, 30,000 in the US, and about 10,000 in the UK; Tay-Sachs disease, which results in spasticity and death in childhood. The BRCA1 and BRCA2 inherited genes predispose women with a significantly greater chance of developing breast or ovarian cancer. Sickle-cell anaemia, in which inheriting the sickle cell gene from both parents causes the red blood cells to spontaneously “sickle” during a stress crisis; heart disease, of which many types are passed on genetically; haemophilia, a bleeding disorder caused by the absence of genetic clotting agent and. Huntington disease, a genetic condition which slowly kills victims by affecting cognitive functions and neurological status. Further, genomics play a significant role in mortality from chronic conditions such as cancer, diabetes and heart disease.

A world first

Huang and his colleagues set out to see if they could replace a gene in a single-cell fertilized human embryo. In principle, all cells produced as the embryo develops would then have the replaced gene. The embryos used by Huang were obtained from fertility clinics, but had an extra set of chromosomes, which prevented them from resulting in a live birth, though they did undergo the first stages of development. The technique used by Huang’s team involved injecting embryos with the enzyme complex CRISPR-Cas9, which, as described above, acts like is a pair of molecular scissors that can be designed to find and remove a specific strand of DNA inside a cell, and then replace it with a new piece of genetic material.

The science underpinning gene editing

In the two videos below Roger Kornberg, professor of medicine at Stanford University and 2006 Nobel Prize winner for Chemistry for his work on “transcription”, the process by which DNA is converted into RNA, explains the science, which underpins gene-editing technology:

How biological information, encoded in the genome, is accessed for all human activity

Impact of human genome determination on pharmaceuticals

An immature technology

Huang’s team injected 86 embryos, and then waited 48 hours; enough time for the CRISPR-Cas9 system, and the molecules that replace the missing DNA to act, and for the embryos to grow to about eight cells each. Of the 71 embryos that survived, 54 were genetically tested. Only 28 were successfully spliced, and only a fraction of those contained the replacement genetic material.

Therapy to cure HIV

Fan, the Chinese scientist who used CRISPR in an endeavor to discover a therapy for HIV/Aids, collected 213 fertilized human eggs, donated by 87 patients, which like embryos used by Huang, were unsuitable for implantation, as part of in vitro fertility therapy. Fan used CRISPR–Cas9 to introduce into some of the embryos a mutation that cripples an immune-cell gene called CCR5. Some humans who naturally carry this mutation are resistant to HIV, because the mutation alters the CCR5 protein in a way that prevents the virus from entering the T-cells it tries to infect. Fan’s analysis showed that only 4 of the 26 human embryos targeted were successfully modified.

Deleting and altering genes not targeted

In 2012, soon after scientists reported that CRISPR could edit DNA, experts raised concerns about “off-target effects,” where CRISPR inadvertently deletes or alters genes not targeted by the scientists. This can happen because one molecule in CRISPR acts like a bloodhound, and sniffs around the genome until it finds a match to its own specific sequence. Unfortunately, the human genome has billions of potential matches, which raises the possibility that the procedure might result in more than one match.

Huang is considering ways to decrease the number of “off-target” mutations by tweaking the enzymes to guide them more precisely to a desired spot, introducing the enzymes in a different format in order to try to regulate their lifespans, allowing enzymes to be shut down before mutations accumulate; and varying the concentrations of the introduced enzymes and repair molecules. He is also, considering using other gene-editing techniques, such as LATENT.

The slippery slope to eugenics

Despite the potential therapeutic benefits from gene editing, critics suggest that genetic changes to embryos, known as germline modifications, are the start of a “slippery slope” that could eventually lead to the creation of a two-tiered society, with elite citizens, genetically engineered to be smarter, healthier and to live longer, and an underclass of biologically run-of-the-mill humans.

Some people believe that the work of Huang, Fan and others crosses a significant ethical line: because germline modifications are heritable, they therefore could have an unpredictable effect on future generations. Few people would argue against using CRISPR to treat terminal cancer patients, but what about treating chronic diseases or disabilities? If cystic fibrosis can be corrected with CRISPR, should obesity, which is associated with many life-threatening conditions? Who decides where the line is drawn?

40 countries have banned CRISPR in human embryos. Two prominent journals, Nature and Science, rejected Huang’s 2012 research paper on ethical grounds, and subsequently, Nature published a note calling for a global moratorium on the genetic modification of human embryos, suggesting that there are “grave concerns” about the ethics and safety of the technology.

A 2016 report from the Nuffield Council on Bioethics suggests that because of the steep rise in genetic technology, and the general availability of cheap, simple-to-use gene-editing kits, which make it relatively straightforward for enthusiasts outside laboratories to perform experiments, there needs to be internationally agreed ethical codes before the technology develops further.

Recently, the novelist Kazuo Ishiguro, among others, joined the debate, arguing that social changes unleashed by gene editing technologies could undermine core human values. “We’re coming close to the point where we can, objectively in some sense, create people who are superior to others,” says Ishiguro.

Takeaways

CRISPR has been described as the “Model T of genetics”. Just as the Model T was the first motor vehicle to be successfully mass-produced, and made driving cheap and accessible to the masses, so CRISPR has made a complex process to alter any piece of DNA in any species easy, cheap and reliable, and accessible to scientists throughout the world. Although CRISPR still faces some technical challenges, and notwithstanding that it has ignited significant protests on ethical grounds, there is now a global race to push the boundaries of its capabilities well beyond its present limits.

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The critical importance of new rapid influenza diagnostic tests

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Influenza, or flu, outbreaks are recurrent and every year pose a significant risk to global health
Influenza affects millions: each year 3m to 5m cases of severe disease and 500,000 deaths
Pandemics occur about three times a century
The 1918 flu pandemic killed 21m . . . Total deaths in World War I was 17m
Effective treatment of patients with respiratory illness depend on accurate and timely diagnosis
Early diagnosis of influenza can reduce the inappropriate use of antibiotics and provide the option of using antiviral therapy
Rapid Influenza Diagnostic Tests (RIDTs) are useful in determining whether outbreaks of respiratory disease might be due to influenza
RIDTs vary in their sensitivity, specificity, complexity, and time to produce results
There is a pressing need for faster, cheaper, and easier-to-use flu tests with higher levels of sensitivity and specificity than those currently available
The large, fast-growing, global and under-served RIDT market drives a host of initiatives
Various development challenges pose significant threats

The critical importance of new rapid influenza diagnostic tests

What challenges face developers of cheap, easy-to-use, rapid and accurate diagnostic tests for influenza, or flu, which improve on tests currently available?

Influenza

Influenza is a highly contagious respiratory illness caused by a virus, and occurs in distinct outbreaks of varying extent every year. Its epidemiologic pattern reflects the changing nature of the antigenic properties of influenza viruses. The viruses subsequent spread depends upon multiple factors, including transmissibility and the susceptibility of the population. Influenza A viruses, in particular, have a remarkable ability to undergo periodic changes in the antigenic characteristics of their envelope glycoproteins; the hemagglutinin and the neuraminidase. Anyone can get influenza. It is usually spread by the coughs and sneezes of an infected person. You can also catch flu by touching an infected person (e.g. shaking hands). Adults are contagious one to two days before getting symptoms and up to seven days after becoming ill, which means that you can spread the influenza virus before you even know you are infected. Influenza presents as a sudden onset of high fever, myalgia, headache and severe malaise, cough (usually dry), sore throat, and runny nose. There are several treatment options, which aim to ease symptoms until the infection goes, and aims to prevent complications. Most healthy people recover within one to two weeks without requiring any medical treatment. However, influenza can cause severe illness or death especially in people at high risk such as the very young, the elderly, and people suffering from medical conditions such as lung diseases, diabetes, cancer, kidney or heart problems.

Costly killer

Influenza is a cruel, costly killer with a history of pandemics. It causes millions of upper respiratory tract infections every year as it spreads around the world in seasonal epidemics, and poses on-going risks to health. The most vulnerable are the young, the old and those with chronic medical conditions such as heart disease, respiratory problems and diabetes. Each year, on average 5% to 20% of populations in wealthy countries get influenza. In the US it causes more than 200,000 hospitalizations and 36,000 deaths annually, and each year costs the American economy between US$71 to US$167bn.

History of pandemics

The 1918-19 “Spanish Flu” pandemic caused 21m deaths, and was one of three 20th century influenza pandemics. At least four pandemics occurred in the 19th century, and the first pandemic of the 21st century was the 2009 “Swine Flu”. Its virulence and global human impact was less deadly than originally feared, but it still resulted in 18,449 laboratory confirmed deaths. If you account for people who died as a result of complications precipitated by the Swine Flu, the actual death toll is significantly higher. Mindful of the potential accelerated spread of a pandemic subtype of the influenza virus, the World Health Organization (WHO), and national governments continuously monitor influenza viruses. Assessment of pathogenicity and virulence is the key to taking appropriate healthcare actions in the event of an outbreak.

However, without widespread access to improved diagnostic tests, each year millions will not receive timely anti-viral medication, tens of thousands of influenza sufferers will develop complications, and thousands will die unnecessarily, as the growing interconnections and complexity of the world present an increasing challenge to influenza prevention and control.

The influenza viruses

Influenza is a single-stranded, helically shaped, RNA virus of the orthomyxovirus family. Influenza viruses are divided into two groups: A and B. Influenza A has two subtypes which are important for humans: A(H3N2) and A(H1N1). The former is currently associated with most deaths. Influenza viruses are defined by two different protein components, known as antigens, on the surface of the virus. They are haemagglutinin (H) and neuraminidase (N) components. Influenza viruses circulate in all parts of the world, and mutate at a low level, referred to as "genetic drift", which allows influenza to continuously evolve and escape from the pressures of population immunity. This means that each individual is always susceptible to infections with new strains of the virus. "Genetic shift" occurs when a strain of influenza A virus completely replaces one or more of its gene segments with the homologous segments from another influenza A strain, a process known as reassortment. If the new segments are from an animal influenza virus to which humans have had no exposure and no immunity, pandemics may ensue.

Gold standard diagnosis rarely used

The gold standard method for the detection of influenza viruses is rarely performed, as patients with suspected influenza are most likely to be seen by a primary care doctor with limited resources, and the gold standard test requires sophisticated laboratory infrastructure, and takes at least 48 hours. Even the faster Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test, which is a relatively new type of molecular assay that uses isothermal amplification of viral cells, has a turnaround time of four to six hours. It is also expensive, and therefore not commonly used.

The slowness and expense of traditional influenza tests led to the development of an array of commercially available Rapid Influenza Diagnostic Tests (RIDTs), which screen for influenza viruses, and provide results within as little as 15 minutes after sample collection and processing. Such tests are largely immunoassays that can identify the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens and display the results in a qualitative way (positive or negative). About 10 such tests have FDA approval and are available in the US. About 20 have been determined suitable for the European market. All are growing in their usage. However, the RIDTs vary in their sensitivity, specificity, complexity, and in the time needed to produce results.

Tests rule in Influenza but do not rule it out

According to the Centers for Disease Control and Prevention (CDC) the commercially available RIDTs in America have a sensitivity ranging from 50% to 70%. This means that in up to 50% of influenza cases, test results will still be negative. A study showed that tests for the N1H1 virus, a subtype of influenza A that was the most common cause of the Swine Flu in 2009, and is associated with the 1918 Spanish Flu pandemic, have a sensitivity ranging from 32% to 50% depending on the brand of test. A 2012 meta-analysis of the accuracy of RIDTs reported an average sensitivity for detecting influenza in adults of only 54%. Sensitivity in children is somewhat higher since they tend to shed a greater quantity of virus. Thus some 30% to 50% of flu samples that would register positive by the gold standard viral culture test may give a false negative when using a RIDT, and some may indicate a false positive when a person is not infected with influenza. Thus, RIDTs that are currently available allow Influenza to be ruled in but not ruled out. More sensitive tests are needed.

New flu tests

There are a number of innovative nano-scale molecular diagnostic influenza tests in development, which are expected to deliver more accurate validations than existing antigen-based molecular tests. The new tests use a platform, comprised of an extremely thin layer of material, which detects the presence of influenza proteins in saliva or blood. This is attached to an electronic chip, which transforms the platform into a sensor. This is an essential part of the measuring device as it converts the input signal to the quantity suitable for measurement and interpretation. The presence of influenza proteins in saliva or blood triggers an electrical signal in the chip, which is then communicated to a mobile phone.

Here Roger Kornberg, Professor of Medicine at Stanford University and 2006 Nobel Laureate for Chemistry describes how advances in molecular science are enabling the replacement of traditional in vitro diagnostics with rapid, virtually instantaneous point-of-care diagnostics without resort to complex processes or elaborate infrastructure. Antiviral drugs for influenza are available in some countries and may reduce severe complications and deaths. Ideally they need to be administered early (within 48 hours of onset of symptoms) in the disease. An almost instantaneous point-of-care test will enable better access to appropriate treatment particularly in primary care:

Challenges

Notwithstanding all the recent scientific advances, new and innovative influenza detection tests will need to overcome significant challenges to outperform current RIDTs. In addition to the usual challenges associated with sensitivity and specificity, new developers have to be aware of recent changes in immunochromatographic antigen detection testing for influenza viruses, and the rapid development of commercially available nucleic acid amplification tests. Also, there are the usual development challenges associated with miniaturization, fabrication, scaling, marketing, and regulation. Effective from 13 February 2017, the FDA reclassified antigen based rapid influenza detection tests from class I into class II devices. Class II devices are higher risk than Class I, and require greater regulatory controls to provide reasonable assurance of the device’s safety and effectiveness. This was provoked by the potential for the devices to fail to detect newer versions of the influenza virus. For instance, a novel variant of influenza A,H7N9, has emerged in Asia, and H5N1 is also re-emergent.

Another challenge, especially for start-ups with limited resources, is the fluctuating nature of the influenza virus itself. A bad year for patients, when influenza causes millions of people to become ill, is a good year for manufacturers of RIDTs. Conversely, a good year for patients, when influenza affects a lower percentage of the population, is a bad year for manufacturers who suffer from unsold inventory, and reduced revenues. Thus, the vagaries of the flu virus not only have the potential to kill millions of people, they also pose a significant threat to start-ups dedicated to developing RIDTs.

Takeaways

Despite all the challenges, there is a significant commercial opportunity in the current under-served global RIDT market for improved tests. Each year, in the US, more than 1bn people visit primary care doctors, and in the UK, the NHS, deals with over 1m patients every 36 hours. The global in vitro diagnostics market was valued at US$60bn in 2016. Between 2016 and 2021, the market is expected to grow at a CAGR of 5.5% to reach US$79bn by 2021. Over the same period, the global point-of-care diagnostics sub-market is expected to grow at a CAGR of 10% to reach US$37bn by 2021. Large corporates, small start-ups, and university research laboratories have spotted the opportunity, and started developing new and innovative RIDTs. Given that each-year influenza causes widespread morbidity as well as mortality, it should be a matter of priority to support all efforts to develop swift and reliable RIDTs. A significant step forward would be a RIDT with greater sensitivity and usability such that the test could be administered and a result given within a 10-minute primary care consultation.