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."
Talaris Therapeutics, Inc., a biotech company based in Louisville, Ky., is edging closer to eradicating the need for immunosuppressive drugs for kidney transplant patients.
In a series of research trials, Talaris is infusing patients with immune system stem cells from their kidney donor to create a donor-derived immune system that accepts the organ without the need for anti-rejection medications. That newly generated system does not attack other parts of the recipient’s body and also fights off infections and diseases as a healthy immune system would.
Talaris is now moving into the final clinical trial, phase III, before submitting for FDA approval. Known as Freedom-1, this trial has 17 sites open throughout the U.S., and Talaris will enroll a total of 120 kidney transplant recipients. One day after receiving their donor’s kidney, 80 people will undergo the company’s therapy, involving the donor’s stem cells and other critical cells that are processed at their facility. Forty will have a regular kidney transplant and remain on immunosuppression to provide a control group.
“The beauty of this procedure is that I don’t have to take all of the anti-rejection drugs,” says Robert Waddell, a finance professional. “I forget that I ever had any kidney issues. That’s how impactful it is.”
The procedure was pioneered decades ago by Suzanne Ildstad as a faculty member at the University of Pittsburgh before she became founding CEO of Talaris and then its Chief Scientific Officer. If approved by the FDA, the method could soon become the standard of care for patients in need of a kidney transplant.
“We are working to find a way to reprogram the immune system of transplant recipients so that it sees the donated organ as [belonging to one]self and doesn’t attack it,” explains Scott Requadt, CEO of Talaris. “That obviates the need for lifelong immunosuppression.”
Each year, there are roughly 20,000 kidney transplants, making kidneys the most transplanted organ. About 6,500 of those come from living donors, while deceased donors provide roughly 13,000.
One of the challenges, Requadt points out, is that kidney transplant recipients aren’t always aware of all the implications of immunosuppression. Typically, they will need to take about 20 anti-rejection drugs several times a day to provide immunosuppression as well as treat complications caused by the toxicities of immunosuppression medications. The side effects of chronic immunosuppression include weight gain, high blood pressure, and high cholesterol. These cardiovascular comorbidities, Requadt says, are “often more frequently the cause of death than failure of a transplanted organ.”
Patients who are chronically immunosuppressed generally have much higher rates of infections and cancers that have an immune component to them, such as skin cancers.
For the past couple of years, those patients have experienced heightened anxiety because of the COVID-19 pandemic. Immune-suppressing medicine used to protect their new organ also makes it hard for patients to build immunity to foreign invaders like COVID-19.
A study appearing in the Proceedings of the National Academy of Sciences found the probability of a pandemic with similar impact to COVID-19 is about 2 percent in any year, and estimated that the probability of novel disease outbreaks will grow three-fold in the next few decades. All the more reason to identify an FDA-approved alternative to harsh immunosuppressive drugs.
Of the 18 patients during the phase II research trial who received the Talaris therapy, didn’t take immunosuppression medication and were vaccinated, only two ended up with a COVID infection, according to a review of the data. Among patients who needed to continue taking immunosuppressants or those who didn’t have them but were unvaccinated, the rates of infection were between 40 and 60 percent.
In the earlier phase II study by Talaris with 37 patients, the combined transplantation approach allowed 70 percent of patients to get off all immunosuppression.
“We’ve followed that whole cohort for more than six and a half years and one of them for 12 years from transplant, and every single patient that we got off immunosuppression has been able to stay off,” Requadt says.
That one patient, Robert Waddell, 55, was especially thankful to be weaned off immunosuppressive drugs approximately one year after his transplant procedure. The Louisville resident had long watched his mother, sister and other family members with polycystic kidney disease, or PKD, suffer the effects of chronic immunosuppression. That became his greatest fear when he was diagnosed with end stage renal failure.
Waddell enrolled in the phase II research taking place in Louisville after learning about it in early 2006. He chose to remain in the study when it relocated its clinical headquarters to Northwestern University’s medical center in Chicago a couple years later.
Before surgery, he underwent an enervating regimen of chemotherapy and radiation. It’s required to clear out a patient’s bone marrow cells so that they can be replaced by the donor’s cells. Waddell says the result was worth it: he had his combined kidney and immune system stem cell transplant in May 2009, without any need for chronic immunosuppression.
“I call it ‘short-term pain, long-term gain,’ because it was difficult to go through the conditioning, but after that, it was great,” he says. “I’ve talked to so many kidney recipients who say, ‘I wish I would have done that,’ because most people don’t think about clinical trials, but I was very fortunate.”
Waddell has every reason to support the success of this research, especially given the genetic disorder, PKD, that has plagued his family. One of his four children has PKD. He is anxious for the procedure to become standard of care, if and when his son needs it.
The Talaris procedure was pioneered decades ago by Suzanne Ildstad, founding CEO of Talaris and the company's Chief Scientific Officer, pictured here with the current CEO, Scott Requadt.
Talaris
“The beauty of this procedure is that I don’t have to take all of the anti-rejection drugs,” says Waddell, a finance professional. “I forget that I ever had any kidney issues. That’s how impactful it is.”
Talaris will continue to follow Waddell and the rest of his cohort to track the effectiveness and safety of the procedure. According to Requadt, the average life of a transplanted kidney is 12 to 15 years, partly because the immunosuppressive drugs worsen the functioning of the organ each year.
“We were the first group to show that we could robustly and fairly reproducibly do this in a clinical setting in humans,” Requadt says. “Most important, we’ve been able to show that we can still get a good engraftment of the stem cells from the donor, even if there is a profound…mismatch between the donor and the recipient’s immune systems.”
In kidney transplantation, it’s important to match for human leukocyte antigens (HLA) because there is a better graft survival in HLA-identical kidney transplants compared with HLA mismatched transplants.
About three months after the transplant, Talaris researchers look for evidence that the donated immune cells and stem cells have engrafted, while making a donor immune system for the patient. If more than 50 percent of the T cells contain the donor’s DNA after six months, patients can start taking fewer immunosuppressants.
“We know from phase II that in our patients who were able to tolerize [accept the organ without rejection] to their donated organ, we saw completely preserved and in fact slightly increased kidney function,” Requadt says. “So, it stands to reason that if you eliminate the drugs that are associated with declining kidney function that you would preserve kidney function, so hopefully the patient will have that one kidney for life.”
Matthew Cooper, director of kidney and pancreas transplantation for MedStar Georgetown Transplant Institute in Washington, DC, states that, “Right now, the Achilles’ heel is we have such a long waiting list and few donors that people die every day waiting for a kidney transplant. Eventually, we will eliminate the organ shortage so that people won’t die from organ failure.”
Cooper, a nationally recognized clinical transplant surgeon for 20 years, says when he started his career, finding a way for patients to forgo immunosuppression was considered “the Holy Grail” of modern transplant medicine.
“Now that we’ve got the protocols in place and some personal examples of how that can happen, it’s pretty exciting to see that all coming together,” he adds.
Researchers advance drugs that treat pain without addiction
Opioids are one of the most common ways to treat pain. They can be effective but are also highly addictive, an issue that has fueled the ongoing opioid crisis. In 2020, an estimated 2.3 million Americans were dependent on prescription opioids.
Opioids bind to receptors at the end of nerve cells in the brain and body to prevent pain signals. In the process, they trigger endorphins, so the brain constantly craves more. There is a huge risk of addiction in patients using opioids for chronic long-term pain. Even patients using the drugs for acute short-term pain can become dependent on them.
Scientists have been looking for non-addictive drugs to target pain for over 30 years, but their attempts have been largely ineffective. “We desperately need alternatives for pain management,” says Stephen E. Nadeau, a professor of neurology at the University of Florida.
A “dimmer switch” for pain
Paul Blum is a professor of biological sciences at the University of Nebraska. He and his team at Neurocarrus have created a drug called N-001 for acute short-term pain. N-001 is made up of specially engineered bacterial proteins that target the body’s sensory neurons, which send pain signals to the brain. The proteins in N-001 turn down pain signals, but they’re too large to cross the blood-brain barrier, so they don’t trigger the release of endorphins. There is no chance of addiction.
When sensory neurons detect pain, they become overactive and send pain signals to the brain. “We wanted a way to tone down sensory neurons but not turn them off completely,” Blum reveals. The proteins in N-001 act “like a dimmer switch, and that's key because pain is sensation overstimulated.”
Blum spent six years developing the drug. He finally managed to identify two proteins that form what’s called a C2C complex that changes the structure of a subunit of axons, the parts of neurons that transmit electrical signals of pain. Changing the structure reduces pain signaling.
“It will be a long path to get to a successful clinical trial in humans," says Stephen E. Nadeau, professor of neurology at the University of Florida. "But it presents a very novel approach to pain reduction.”
Blum is currently focusing on pain after knee and ankle surgery. Typically, patients are treated with anesthetics for a short time after surgery. But anesthetics usually only last for 4 to 6 hours, and long-term use is toxic. For some, the pain subsides. Others continue to suffer after the anesthetics have worn off and start taking opioids.
N-001 numbs sensation. It lasts for up to 7 days, much longer than any anesthetic. “Our goal is to prolong the time before patients have to start opioids,” Blum says. “The hope is that they can switch from an anesthetic to our drug and thereby decrease the likelihood they're going to take the opioid in the first place.”
Their latest animal trial showed promising results. In mice, N-001 reduced pain-like behaviour by 90 percent compared to the control group. One dose became effective in two hours and lasted a week. A high dose had pain-relieving effects similar to an opioid.
Professor Stephen P. Cohen, director of pain operations at John Hopkins, believes the Neurocarrus approach has potential but highlights the need to go beyond animal testing. “While I think it's promising, it's an uphill battle,” he says. “They have shown some efficacy comparable to opioids, but animal studies don't translate well to people.”
Nadeau, the University of Florida neurologist, agrees. “It will be a long path to get to a successful clinical trial in humans. But it presents a very novel approach to pain reduction.”
Blum is now awaiting approval for phase I clinical trials for acute pain. He also hopes to start testing the drug's effect on chronic pain.
Learning from people who feel no pain
Like Blum, a pharmaceutical company called Vertex is focusing on treating acute pain after surgery. But they’re doing this in a different way, by targeting a sodium channel that plays a critical role in transmitting pain signals.
In 2004, Stephen Waxman, a neurology professor at Yale, led a search for genetic pain anomalies and found that biologically related people who felt no pain despite fractures, burns and even childbirth had mutations in the Nav1.7 sodium channel. Further studies in other families who experienced no pain showed similar mutations in the Nav1.8 sodium channel.
Scientists set out to modify these channels. Many unsuccessful efforts followed, but Vertex has now developed VX-548, a medicine to inhibit Nav1.8. Typically, sodium ions flow through sodium channels to generate rapid changes in voltage which create electrical pulses. When pain is detected, these pulses in the Nav1.8 channel transmit pain signals. VX-548 uses small molecules to inhibit the channel from opening. This blocks the flow of sodium ions and the pain signal. Because Nav1.8 operates only in peripheral nerves, located outside the brain, VX-548 can relieve pain without any risk of addiction.
"Frankly we need drugs for chronic pain more than acute pain," says Waxman.
The team just finished phase II clinical trials for patients following abdominoplasty surgery and bunionectomy surgery.
After abdominoplasty surgery, 76 patients were treated with a high dose of VX-548. Researchers then measured its effectiveness in reducing pain over 48 hours, using the SPID48 scale, in which higher scores are desirable. The score for Vertex’s drug was 110.5 compared to 72.7 in the placebo group, whereas the score for patients taking an opioid was 85.2. The study involving bunionectomy surgery showed positive results as well.
Waxman, who has been at the forefront of studies into Nav1.7 and Nav1.8, believes that Vertex's results are promising, though he highlights the need for further clinical trials.
“Blocking Nav1.8 is an attractive target,” he says. “[Vertex is] studying pain that is relatively simple and uniform, and that's key to having a drug trial that is informative. But the study needs to be replicated and frankly we need drugs for chronic pain more than acute pain. If this is borne out by additional studies, it's one important step in a journey.”
Vertex will be launching phase III trials later this year.
Finding just the right amount of Nerve Growth Factor
Whereas Neurocarrus and Vertex are targeting short-term pain, a company called Levicept is concentrating on relieving chronic osteoarthritis pain. Around 32.5 million Americans suffer from osteoarthritis. Patients commonly take NSAIDs, or non-steroidal anti-inflammatory drugs, but they cannot be taken long-term. Some take opioids but they aren't very effective.
Levicept’s drug, Levi-04, is designed to modify a signaling pathway associated with pain. Nerve Growth Factor (NGF) is a neurotrophin: it’s involved in nerve growth and function. NGF signals by attaching to receptors. In pain there are excess neurotrophins attaching to receptors and activating pain signals.
“What Levi-04 does is it returns the natural equilibrium of neurotrophins,” says Simon Westbrook, the CEO and founder of Levicept. It stabilizes excess neurotrophins so that the NGF pathway does not signal pain. Levi-04 isn't addictive since it works within joints and in nerves outside the brain.
Westbrook was initially involved in creating an anti-NGF molecule for Pfizer called Tanezumab. At first, Tanezumab seemed effective in clinical trials and other companies even started developing their own versions. However, a problem emerged. Tanezumab caused rapidly progressive osteoarthritis, or RPOA, in some patients because it completely removed NGF from the system. NGF is not just involved in pain signalling, it’s also involved in bone growth and maintenance.
Levicept has found a way to modify the NGF pathway without completely removing NGF. They have now finished a small-scale phase I trial mainly designed to test safety rather than efficacy. “We demonstrated that Levi-04 is safe and that it bound to its target, NGF,” says Westbrook. It has not caused RPOA.
Professor Philip Conaghan, director of the Leeds Institute of Rheumatic and Musculoskeletal Medicine, believes that Levi-04 has potential but urges the need for caution. “At this early stage of development, their molecule looks promising for osteoarthritis pain,” he says. “They will have to watch out for RPOA which is a potential problem.”
Westbrook starts phase II trials with 500 patients this summer to check for potential side effects and test the drug’s efficacy.
There is a real push to find an effective alternative to opioids. “We have a lot of work to do,” says Professor Waxman. “But I am confident that we will be able to develop new, much more effective pain therapies.”