What’s the Right Way to Regulate Gene-Edited Crops?
In the next few decades, humanity faces its biggest food crisis since the invention of the plow. The planet's population, currently 7.6 billion, is expected to reach 10 billion by 2050; to avoid mass famine, according to the World Resource Institute, we'll need to produce 70 percent more calories than we do today.
Imagine that a cheap, easy-to-use, and rapidly deployable technology could make crops more fertile and strengthen their resistance to threats.
Meanwhile, climate change will bring intensifying assaults by heat, drought, storms, pests, and weeds, depressing farm yields around the globe. Epidemics of plant disease—already laying waste to wheat, citrus, bananas, coffee, and cacao in many regions—will spread ever further through the vectors of modern trade and transportation.
So here's a thought experiment: Imagine that a cheap, easy-to-use, and rapidly deployable technology could make crops more fertile and strengthen their resistance to these looming threats. Imagine that it could also render them more nutritious and tastier, with longer shelf lives and less vulnerability to damage in shipping—adding enhancements to human health and enjoyment, as well as reduced food waste, to the possible benefits.
Finally, imagine that crops bred with the aid of this tool might carry dangers. Some could contain unsuspected allergens or toxins. Others might disrupt ecosystems, affecting the behavior or very survival of other species, or infecting wild relatives with their altered DNA.
Now ask yourself: If such a technology existed, should policymakers encourage its adoption, or ban it due to the risks? And if you chose the former alternative, how should crops developed by this method be regulated?
In fact, this technology does exist, though its use remains mostly experimental. It's called gene editing, and in the past five years it has emerged as a potentially revolutionary force in many areas—among them, treating cancer and genetic disorders; growing transplantable human organs in pigs; controlling malaria-spreading mosquitoes; and, yes, transforming agriculture. Several versions are currently available, the newest and nimblest of which goes by the acronym CRISPR.
Gene editing is far simpler and more efficient than older methods used to produce genetically modified organisms (GMOs). Unlike those methods, moreover, it can be used in ways that leave no foreign genes in the target organism—an advantage that proponents argue should comfort anyone leery of consuming so-called "Frankenfoods." But debate persists over what precautions must be taken before these crops come to market.
Recently, two of the world's most powerful regulatory bodies offered very different answers to that question. The United States Department of Agriculture (USDA) declared in March 2018 that it "does not currently regulate, or have any plans to regulate" plants that are developed through most existing methods of gene editing. The Court of Justice of the European Union (ECJ), by contrast, ruled in July that such crops should be governed by the same stringent regulations as conventional GMOs.
Some experts suggest that the broadly permissive American approach and the broadly restrictive EU policy are equally flawed.
Each announcement drew protests, for opposite reasons. Anti-GMO activists assailed the USDA's statement, arguing that all gene-edited crops should be tested and approved before marketing. "You don't know what those mutations or rearrangements might do in a plant," warned Michael Hansen, a senior scientist with the advocacy group Consumers Union. Biotech boosters griped that the ECJ's decision would stifle innovation and investment. "By any sensible standard, this judgment is illogical and absurd," wrote the British newspaper The Observer.
Yet some experts suggest that the broadly permissive American approach and the broadly restrictive EU policy are equally flawed. "What's behind these regulatory decisions is not science," says Jennifer Kuzma, co-director of the Genetic Engineering and Society Center at North Carolina State University, a former advisor to the World Economic Forum, who has researched and written extensively on governance issues in biotechnology. "It's politics, economics, and culture."
The U.S. Welcomes Gene-Edited Food
Humans have been modifying the genomes of plants and animals for 10,000 years, using selective breeding—a hit-or-miss method that can take decades or more to deliver rewards. In the mid-20th century, we learned to speed up the process by exposing organisms to radiation or mutagenic chemicals. But it wasn't until the 1980s that scientists began modifying plants by altering specific stretches of their DNA.
Today, about 90 percent of the corn, cotton and soybeans planted in the U.S. are GMOs; such crops cover nearly 4 million square miles (10 million square kilometers) of land in 29 countries. Most of these plants are transgenic, meaning they contain genes from an unrelated species—often as biologically alien as a virus or a fish. Their modifications are designed primarily to boost profit margins for mechanized agribusiness: allowing crops to withstand herbicides so that weeds can be controlled by mass spraying, for example, or to produce their own pesticides to lessen the need for chemical inputs.
In the early days, the majority of GM crops were created by extracting the gene for a desired trait from a donor organism, multiplying it, and attaching it to other snippets of DNA—usually from a microbe called an agrobacterium—that could help it infiltrate the cells of the target plant. Biotechnologists injected these particles into the target, hoping at least one would land in a place where it would perform its intended function; if not, they kept trying. The process was quicker than conventional breeding, but still complex, scattershot, and costly.
Because agrobacteria can cause plant tumors, Kuzma explains, policymakers in the U.S. decided to regulate GMO crops under an existing law, the Plant Pest Act of 1957, which addressed dangers like imported trees infested with invasive bugs. Every GMO containing the DNA of agrobacterium or another plant pest had to be tested to see whether it behaved like a pest, and undergo a lengthy approval process. By 2010, however, new methods had been developed for creating GMOs without agrobacteria; such plants could typically be marketed without pre-approval.
Soon after that, the first gene-edited crops began appearing. If old-school genetic engineering was a shotgun, techniques like TALEN and CRISPR were a scalpel—or the search-and-replace function on a computer program. With CRISPR/Cas9, for example, an enzyme that bacteria use to recognize and chop up hostile viruses is reprogrammed to find and snip out a desired bit of a plant or other organism's DNA. The enzyme can also be used to insert a substitute gene. If a DNA sequence is simply removed, or the new gene comes from a similar species, the changes in the target plant's genotype and phenotype (its general characteristics) may be no different from those that could be produced through selective breeding. If a foreign gene is added, the plant becomes a transgenic GMO.
Companies are already teeing up gene-edited products for the U.S. market, like a cooking oil and waxy corn.
This development, along with the emergence of non-agrobacterium GMOs, eventually prompted the USDA to propose a tiered regulatory system for all genetically engineered crops, beginning with an initial screening for potentially hazardous metaboloids or ecological impacts. (The screening was intended, in part, to guard against the "off-target effects"—stray mutations—that occasionally appear in gene-edited organisms.) If no red flags appeared, the crop would be approved; otherwise, it would be subject to further review, and possible regulation.
The plan was unveiled in January 2017, during the last week of the Obama presidency. Then, under the Trump administration, it was shelved. Although the USDA continues to promise a new set of regulations, the only hint of what they might contain has been Secretary of Agriculture Sonny Perdue's statement last March that gene-edited plants would remain unregulated if they "could otherwise have been developed through traditional breeding techniques, as long as they are not plant pests or developed using plant pests."
Because transgenic plants could not be "developed through traditional breeding techniques," this statement could be taken to mean that gene editing in which foreign DNA is introduced might actually be regulated. But because the USDA regulates conventional transgenic GMOs only if they trigger the plant-pest stipulation, experts assume gene-edited crops will face similarly limited oversight.
Meanwhile, companies are already teeing up gene-edited products for the U.S. market. An herbicide-resistant oilseed rape, developed using a proprietary technique, has been available since 2016. A cooking oil made from TALEN-tweaked soybeans, designed to have a healthier fatty-acid profile, is slated for release within the next few months. A CRISPR-edited "waxy" corn, designed with a starch profile ideal for processed foods, should be ready by 2021.
In all likelihood, none of these products will have to be tested for safety.
In the E.U., Stricter Rules Apply
Now let's look at the European Union. Since the late 1990s, explains Gregory Jaffe, director of the Project on Biotechnology at the Center for Science in the Public Interest, the EU has had a "process-based trigger" for genetically engineered products: "If you use recombinant DNA, you are going to be regulated." All foods and animal feeds must be approved and labeled if they consist of or contain more than 0.9 percent GM ingredients. (In the U.S., "disclosure" of GM ingredients is mandatory, if someone asks, but labeling is not required.) The only GM crop that can be commercially grown in EU member nations is a type of insect-resistant corn, though some countries allow imports.
European scientists helped develop gene editing, and they—along with the continent's biotech entrepreneurs—have been busy developing applications for crops. But European farmers seem more divided over the technology than their American counterparts. The main French agricultural trades union, for example, supports research into non-transgenic gene editing and its exemption from GMO regulation. But it was the country's small-farmers' union, the Confédération Paysanne, along with several allied groups, that in 2015 submitted a complaint to the ECJ, asking that all plants produced via mutagenesis—including gene-editing—be regulated as GMOs.
At this point, it should be mentioned that in the past 30 years, large population studies have found no sign that consuming GM foods is harmful to human health. GMO critics can, however, point to evidence that herbicide-resistant crops have encouraged overuse of herbicides, giving rise to poison-proof "superweeds," polluting the environment with suspected carcinogens, and inadvertently killing beneficial plants. Those allegations were key to the French plaintiffs' argument that gene-edited crops might similarly do unexpected harm. (Disclosure: Leapsmag's parent company, Bayer, recently acquired Monsanto, a maker of herbicides and herbicide-resistant seeds. Also, Leaps by Bayer, an innovation initiative of Bayer and Leapsmag's direct founder, has funded a biotech startup called JoynBio that aims to reduce the amount of nitrogen fertilizer required to grow crops.)
The ruling was "scientifically nonsensical. It's because of things like this that I'll never go back to Europe."
In the end, the EU court found in the Confédération's favor on gene editing—though the court maintained the regulatory exemption for mutagenesis induced by chemicals or radiation, citing the 'long safety record' of those methods.
The ruling was "scientifically nonsensical," fumes Rodolphe Barrangou, a French food scientist who pioneered CRISPR while working for DuPont in Wisconsin and is now a professor at NC State. "It's because of things like this that I'll never go back to Europe."
Nonetheless, the decision was consistent with longstanding EU policy on crops made with recombinant DNA. Given the difficulty and expense of getting such products through the continent's regulatory system, many other European researchers may wind up following Barrangou to America.
Getting to the Root of the Cultural Divide
What explains the divergence between the American and European approaches to GMOs—and, by extension, gene-edited crops? In part, Jennifer Kuzma speculates, it's that Europeans have a different attitude toward eating. "They're generally more tied to where their food comes from, where it's produced," she notes. They may also share a mistrust of government assurances on food safety, borne of the region's Mad Cow scandals of the 1980s and '90s. In Catholic countries, consumers may have misgivings about tinkering with the machinery of life.
But the principal factor, Kuzma argues, is that European and American agriculture are structured differently. "GM's benefits have mostly been designed for large-scale industrial farming and commodity crops," she says. That kind of farming is dominant in the U.S., but not in Europe, leading to a different balance of political power. In the EU, there was less pressure on decisionmakers to approve GMOs or exempt gene-edited crops from regulation—and more pressure to adopt a GM-resistant stance.
Such dynamics may be operating in other regions as well. In China, for example, the government has long encouraged research in GMOs; a state-owned company recently acquired Syngenta, a Swiss-based multinational corporation that is a leading developer of GM and gene-edited crops. GM animal feed and cooking oil can be freely imported. Yet commercial cultivation of most GM plants remains forbidden, out of deference to popular suspicions of genetically altered food. "As a new item, society has debates and doubts on GMO techniques, which is normal," President Xi Jinping remarked in 2014. "We must be bold in studying it, [but] be cautious promoting it."
The proper balance between boldness and caution is still being worked out all over the world. Europe's process-based approach may prevent researchers from developing crops that, with a single DNA snip, could rescue millions from starvation. EU regulations will also make it harder for small entrepreneurs to challenge Big Ag with a technology that, as Barrangou puts it, "can be used affordably, quickly, scalably, by anyone, without even a graduate degree in genetics." America's product-based approach, conversely, may let crops with hidden genetic dangers escape detection. And by refusing to investigate such risks, regulators may wind up exacerbating consumers' doubts about GM and gene-edited products, rather than allaying them.
"Science...can't tell you what to regulate. That's a values-based decision."
Perhaps the solution lies in combining both approaches, and adding some flexibility and nuance to the mix. "I don't believe in regulation by the product or the process," says CSPI's Jaffe. "I think you need both." Deleting a DNA base pair to silence a gene, for example, might be less risky than inserting a foreign gene into a plant—unless the deletion enables the production of an allergen, and the transgene comes from spinach.
Kuzma calls for the creation of "cooperative governance networks" to oversee crop genome editing, similar to bodies that already help develop and enforce industry standards in fisheries, electronics, industrial cleaning products, and (not incidentally) organic agriculture. Such a network could include farmers, scientists, advocacy groups, private companies, and governmental agencies. "Safety isn't an all-or-nothing concept," Kuzma says. "Science can tell you what some of the issues are in terms of risk and benefit, but it can't tell you what to regulate. That's a values-based decision."
By drawing together a wide range of stakeholders to make such decisions, she adds, "we're more likely to anticipate future consequences, and to develop a robust approach—one that not only seems more legitimate to people, but is actually just plain old better."
Podcast: Has the First 150-Year-Old Already Been Born
Steven Austad is a pioneer in the field of aging, with over 200 scientific papers and book chapters on pretty much every aspect of biological aging that you could think of. He’s also a strong believer in the potential for anti-aging therapies, and he puts his money where his mouth is. In 2001, he bet a billion dollars that the first person to reach 150-years-old had already been born. I had a chance to talk with Steven for today’s podcast and asked if he still thinks the bet was a good idea, since the oldest person so far (that we know of), Jeanne Calment, died back in 1997. A few days after our conversation, the oldest person in the world, Kane Tanaka, died at 119.
Steven is the Protective Life Endowed Chair in Health Aging Research, a Distinguished Professor and Chair of the Department of Biology at the University of Alabama Birmingham. He's also Senior Scientific Director of the American Federation for Aging Research, which is managing a groundbreaking longevity research trial that started this year. Steven is also a great science communicator with five books, including one that comes out later this year, Methuselah’s Zoo, and he publishes prolifically in national media outlets.
See the rest of his bio linked below in the show notes.
Listen to the Episode
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Steven Austad is featured in the latest episode of Making Sense of Science. He's a distinguished professor of biology at the University of Alabama Birmingham and has a new book due to be published in August, Methuselah's Zoo.
Photo by Steve Wood
Show notes:
2:36 - Steven explains why a particular opossum convinced him to dedicate his career to studying longevity.
6:48 - Steven's billion dollar bet that someone alive today will make it to 150-years-old.
9:15 - The most likely people to make it to 150 (Hint: not men).
10:38 - I ask Steven about Elon Musk’s comments this month that if people lived a really long time, “we’d be stuck with old ideas and society wouldn’t advance.” Steve isn’t so fond of that take.
13:34 - Why women are winning maybe the most important battle of sexes: staying alive. This is an area that Steven has led research on (see show notes).
18:20 - Why women, on average, actually have more morbidities earlier than men, even though they live longer.
23:10 - How the pandemic could affect sex differences in longevity.
24:55 - How often should people work out and get other physical activity to maximize longevity and health span?
29:09 - Steven gave me the latest update on the TAME trial on metformin, and how he and others longevity experts designed this groundbreaking research on longevity not in their offices, not on a zoom call, but in a castle in the Spanish countryside.
32:10 - Which anti-aging therapies are the most promising at this point for future research.
39:32 - The drug cocktail approach to address multiple hallmarks of aging.
41:00 - How to read health news like a scientist.
45:38 - Should we try a Manhattan project for aging?
48:47 - Can Jeff Bezos and Larry Ellison help us live to 150?
Show links:
Steven Austad's bio
Pre-order Steven's new book, Methuselah's Zoo - https://www.amazon.com/dp/B09M2QGRJR/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
Steven's journal article on Sex Differences in Lifespan - https://pubmed.ncbi.nlm.nih.gov/27304504/
Elon Musk's comments on super longevity "asphyxiating" society - https://www.cnbc.com/2022/04/11/elon-musk-on-avoid...
Steven's article on how to read news articles about health like a pro - https://www.nextavenue.org/how-to-read-health-news...
AFAR's research on Targeting Aging with Metformin (TAME) - https://www.afar.org/tame-trial
New therapy may improve stem cell transplants for blood cancers
In 2018, Robyn was diagnosed with myelofibrosis, a blood cancer causing chronic inflammation and scarring. As a research scientist by training, she knew she had limited options. A stem cell transplant is a terminally ill patient's best chance for survival against blood cancers, including leukaemia. It works by destroying a patient's cancer cells and replacing them with healthy cells from a donor.
However, there is a huge risk of Graft vs Host disease (GVHD), which affects around 30-40% of recipients. Patients receive billions of cells in a stem cell transplant but only a fraction are beneficial. The rest can attack healthy tissue leading to GVHD. It affects the skin, gut and lungs and can be truly debilitating.
Currently, steroids are used to try and prevent GVHD, but they have many side effects and are effective in only 50% of cases. “I spoke with my doctors and reached out to patients managing GVHD,” says Robyn, who prefers not to use her last name for privacy reasons. “My concerns really escalated for what I might face post-transplant.”
Then she heard about a new highly precise cell therapy developed by a company called Orca Bio, which gives patients more beneficial cells and fewer cells that cause GVHD. She decided to take part in their phase 2 trial.
How It Works
In stem cell transplants, patients receive immune cells and stem cells. The donor immune cells or T cells attack and kill malignant cells. This is the graft vs leukaemia effect (GVL). The stem cells generate new healthy cells.
Unfortunately, T cells can also cause GVHD, but a rare subset of T cells, called T regulatory cells, can actually prevent GVHD.
Orca’s cell sorting technology distinguishes T regulatory cells from stem cells and conventional T cells on a large scale. It’s this cell sorting technology which has enabled them to create their new cell therapy, called Orca T. It contains a precise combination of stem cells and immune cells with more T regulatory cells and fewer conventional T cells than in a typical stem cell transplant.
“Ivan Dimov’s idea was to spread out the cells, keep them stationary and then use laser scanning to sort the cells,” explains Nate Fernhoff, co-founder of Orca Bio. “The beauty here is that lasers don't care how quickly you move them.”
Over the past 40 years, scientists have been trying to create stem cell grafts that contain the beneficial cells whilst removing the cells that cause GVHD. What makes it even harder is that most transplant centers aren’t able to manipulate grafts to create a precise combination of cells.
Innovative Cell Sorting
Ivan Dimov, Jeroen Bekaert and Nate Fernhoff came up with the idea behind Orca as postdocs at Stanford, working with cell pioneer Irving Weissman. They recognised the need for a more effective cell sorting technology. In a small study at Stanford, Professor Robert Negrin had discovered a combination of T cells, T regulatory cells and stem cells which prevented GVHD but retained the beneficial graft vs leukaemia effect (GVL). However, manufacturing was problematic. Conventional cell sorting is extremely slow and specific. Negrin was only able to make seven highly precise products, for seven patients, in a year. Annual worldwide cases of blood cancer number over 1.2 million.
“We started Orca with this idea: how do we use manufacturing solutions to impact cell therapies,” co-founder Fernhoff reveals. In conventional cell sorting, cells move past a stationary laser which analyses each cell. But cells can only be moved so quickly. At a certain point they start to experience stress and break down. This makes it very difficult to sort the 100 billion cells from a donor in a stem cell transplant.
“Ivan Dimov’s idea was to spread out the cells, keep them stationary and then use laser scanning to sort the cells,” Fernhoff explains. “The beauty here is that lasers don't care how quickly you move them.” They developed this technology and called it Orca Sort. It enabled Orca to make up to six products per week in the first year of manufacturing.
Every product Orca makes is for one patient. The donor is uniquely matched to the patient. They have to carry out the cell sorting procedure each time. Everything also has to be done extremely quickly. They infuse fresh living cells from the donor's vein to the patient's within 72 hours.
“We’ve treated almost 200 patients in all the Orca trials, and you can't do that if you don't fix the manufacturing process,” Fernhoff says. “We're working on what we think is an incredibly promising drug, but it's all been enabled by figuring out how to make a high precision cell therapy at scale.”
Clinical Trials
Orca revealed the results of their phase 1b and phase 2 trials at the end of last year. In their phase 2 trial only 3% of the 29 patients treated with Orca T cell therapy developed chronic GVHD in the first year after treatment. Comparatively, 43% of the 95 patients given a conventional stem cell transplant in a contemporary Stanford trial developed chronic GVHD. Of the 109 patients tested in phase 1b and phase 2 trials, 74% using Orca T didn't relapse or develop any form of GVHD compared to 34% in the control trial.
“Until a randomised study is done, we can make no assumption about the relative efficacy of this approach," says Jeff Szer, professor of haematology at the Royal Melbourne Hospital. "But the holy grail of separating GVHD and GVL is still there and this is a step towards realising that dream.”
Stan Riddell, an immunology professor, at Fred Hutchinson Cancer Centre, believes Orca T is highly promising. “Orca has advanced cell selection processes with innovative methodology and can engineer grafts with greater precision to add cell subsets that may further contribute to beneficial outcomes,” he says. “Their results in phase 1 and phase 2 studies are very exciting and offer the potential of providing a new standard of care for stem cell transplant.”
However, though it is an “intriguing step,” there’s a need for further testing, according to Jeff Szer, a professor of haematology at the Peter MacCallum Cancer Centre at the Royal Melbourne Hospital.
“The numbers tested were tiny and comparing the outcomes to anything from a phase 1/2 setting is risky,” says Szer. “Until a randomised study is done, we can make no assumption about the relative efficacy of this approach. But the holy grail of separating GVHD and GVL is still there and this is a step towards realising that dream.”
The Future
The team is soon starting Phase 3 trials for Orca T. Its previous success has led them to develop Orca Q, a cell therapy for patients who can't find an exact donor match. Transplants for patients who are only a half-match or mismatched are not widely used because there is a greater risk of GVHD. Orca Q has the potential to control GVHD even more and improve access to transplants for many patients.
Fernhoff hopes they’ll be able to help people not just with blood cancers but also with other blood and immune disorders. If a patient has a debilitating disease which isn't life threatening, the risk of GVHD outweighs the potential benefits of a stem cell transplant. The Orca products could take away that risk.
Meanwhile, Robyn has no regrets about participating in the Phase 2 trial. “It was a serious decision to make but I'm forever grateful that I did,” she says. “I have resumed a quality of life aligned with how I felt pre-transplant. I have not had a single issue with GVHD.”
“I want to be able to get one of these products to every patient who could benefit from it,” Fernhoff says. “It's really exciting to think about how Orca's products could be applied to all sorts of autoimmune disorders.”