Researchers advance drugs that treat pain without addiction
New therapies are using creative approaches that target the body’s sensory neurons, which send pain signals to the brain.
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.”
The limits of digital privacy are becoming clearer in the post-Dobbs era, as a wide range of data sources can reveal online and offline activities, including whether a woman seeks an abortion.
Since the recent reversal of Roe v. Wade — the landmark decision establishing a constitutional right to abortion — the vulnerabilities of reproductive health data and various other information stored on digital devices or shared through the Web have risen to the forefront.
Menstrual period tracking apps are an example of how technologies that collect information from users could be weaponized against abortions seekers. The apps, which help tens of millions of users in the U.S. predict when they’re ovulating, may provide evidence that leads to criminal prosecution in states with abortion bans, says Anton T. Dahbura, executive director of the Johns Hopkins University Information Security Institute. In states where abortion is outlawed, “it’s probably best to not use a period tracker,” he says.
Following the Dobbs v. Jackson ruling in late June that overturned Roe, even women who suffered a miscarriage could be suspected of having an abortion in some cases. While using these apps in anonymous mode may appear more secure, “data is notoriously difficult to perfectly anonymize,” Dahbura says. “Whether the data are stored on the user’s device or in the cloud, there are ways to connect that data to the user.”
Completely concealing one’s tracks in cyberspace poses enormous challenges. Digital forensics can take advantage of technology such as GPS apps, security cameras, license plate trackers, credit card transactions and bank records to reconstruct a person’s activities,” Dahbura says. “Abortion service providers are also in a world of risk for similar reasons.”
Practicing “good cyber hygiene” is essential. That’s particularly true in states where private citizens may be rewarded for reporting on women they suspect of having an abortion, such as Texas, which passed a so-called bounty hunter law last fall. To help guard against hacking, Dahbura suggests using strong passwords and two-factor authentication when possible while remaining on alert for phishing scams on email or texts.
Another option for safeguarding privacy is to avoid such apps entirely, but that choice will depend on an individual’s analysis of the risks and benefits, says Leah Fowler, research assistant professor at the University of Houston Law Center, Health Law & Policy Institute.
“These apps are popular because people find them helpful and convenient, so I hesitate to tell anyone to get rid of something they like without more concrete evidence of its nefarious uses,” she says. “I also hate the idea that asking anyone capable of becoming pregnant to opt out of all or part of the digital economy could ever be a viable solution. That’s an enormous policy failure. We have to do better than that.”
The potential universe of abortion-relevant data can include information from a variety of fitness and other biometric trackers, text and social media chat records, call details, purchase histories and medical insurance records.
Instead, Fowler recommends that concerned consumers read the terms of service and privacy policies of the apps they’re using. If some of the terms are unclear, she suggests emailing customer service with questions until the answers are satisfactory. It’s also wise for consumers to research products that meet their specific needs and find out whether other women have raised concerns about specific apps. Users interested in more privacy may want to switch to an app that stores data locally, meaning the data stays on your device, or does not use third-party tracking, so the app-maker is the only company with access to it, she says.
Period tracking apps can be useful for those on fertility journeys, making it easier to store information digitally than on paper charts. But users may want to factor in whether they live in a state with an anti-abortion stance and run the risk of legal issues due to a potential data breach, says Carmel Shachar, executive director of the Petrie-Flom Center for Health Law Policy, Biotechnology, and Bioethics at Harvard Law School.
Consumers’ risks extend beyond period tracking apps in the post-Roe v. Wade era. “Anything that creates digital breadcrumbs to your reproductive choices and conduct could raise concerns — for example, googling ‘abortion providers near me’ or texting your best friend that you are pregnant but do not want to be,” Shachar says. Women also could incriminate themselves by bringing their phones, which may record geolocation data, to the clinic with them.
The potential universe of abortion-relevant data can include information from a variety of fitness and other biometric trackers, text and social media chat records, call details, purchase histories and medical insurance records, says Rebecca Wexler, faculty co-director of the Berkeley Center for Law & Technology. “These data sources can reveal a pregnant person’s decision to seek or obtain an abortion, as well as reveal a healthcare provider’s provision of abortion services and anyone else’s provision of abortion assistance,” she says.
In some situations, people or companies could inadvertently expose themselves to risk after posting on social media with offers of places for abortion seekers to stay after traveling from states with bans. They could be liable for aiding and abetting abortion. At this point, it’s unclear whether states that ban abortion will try to prosecute residents who seek abortions in other states without bans.
Another possibility is that a woman seeking an abortion will be prosecuted based not only on her phone’s data, but also on the data that law enforcement finds on someone else’s device or a shared computer. As a result, “people in one household may find themselves at odds with each other,” says K Royal, faculty fellow at the Center for Law, Science, and Innovation at Arizona State University’s Sandra Day O'Connor College of Law. “This is a very delicate situation.”
Individuals and corporate executives should research their options before leaving a digital footprint. “Guard your privacy carefully, whether you are seeking help or you are seeking to help someone,” Royal says. While she has come across recommendations from other experts who suggest carrying a second phone that is harder to link a person’s identity for certain online activities, “it’s not practical on a general basis.”
The privacy of this health data isn’t fully protected by the law because period trackers, texting services and other apps are not healthcare providers — and as a result, there’s no prohibition on sharing the information with a third party under the Health Insurance Portability and Accountability Act of 1996, says Florencia Marotta-Wurgler, a professor who specializes in online consumer contracts and data privacy at the NYU School of Law.
“So, as long as there is valid consent, then it’s fair game unless you say that it violates the reasonable expectations of consumers,” she says. “But this is pretty unchartered territory at the moment.”
As states implement laws granting anyone the power to report suspected or known pregnancies to law enforcement, anti-choice activists are purchasing reproductive health data from companies that make period apps, says Rebecca Herold, chief executive officer of Privacy & Security Brainiacs in Des Moines, Iowa, and a member of the Emerging Trends Working Group at ISACA, an association focused on information technology governance. They could also buy data on search histories and make it available in places like Texas for “bounty hunters” to find out which women have searched for information about abortions.
Some groups are creating their own apps described as providing general medical information on subjects such as pregnancy health. But they are “ultimately intended to ‘catch’ women” — to identify those who are probably pregnant and dissuade them from having an abortion, to launch harassment campaigns against them, or to report them to law enforcement, anti-choice groups and others in states where such prenatal medical care procedures are now restricted or prohibited, Herold says.
In addition to privacy concerns, the reversal of Roe v. Wade raises censorship issues. Facebook and Instagram have started to remove or flag content, particularly as it relates to providing the abortion pill, says Michael Kleinman, director of the Silicon Valley Initiative at Amnesty International USA, a global organization that promotes human rights.
Facebook and Instagram have rules that forbid private citizens from buying, selling or giving away pharmaceuticals, including the abortion pill, according to a social media post by a communications director for Meta, which owns both platforms. In the same post, though, the Meta official noted that the company’s enforcement of this rule has been “incorrect” in some cases.
“It’s terrifying to think that arbitrary decisions by these platforms can dramatically limit the ability of people to access critical reproductive rights information,” Kleinman says. However, he adds, “as it currently stands, the platforms make unilateral decisions about what reproductive rights information they allow and what information they take down.”
Should We Use Technologies to Enhance Morality?
Should we welcome biomedical technologies that could enhance our ability to tell right from wrong and improve behaviors that are considered immoral such as dishonesty, prejudice and antisocial aggression?
Our moral ‘hardware’ evolved over 100,000 years ago while humans were still scratching the savannah. The perils we encountered back then were radically different from those that confront us now. To survive and flourish in the face of complex future challenges our archaic operating systems might need an upgrade – in non-traditional ways.
Morality refers to standards of right and wrong when it comes to our beliefs, behaviors, and intentions. Broadly, moral enhancement is the use of biomedical technology to improve moral functioning. This could include augmenting empathy, altruism, or moral reasoning, or curbing antisocial traits like outgroup bias and aggression.
The claims related to moral enhancement are grand and polarizing: it’s been both tendered as a solution to humanity’s existential crises and bluntly dismissed as an armchair hypothesis. So, does the concept have any purchase? The answer leans heavily on our definition and expectations.
One issue is that the debate is often carved up in dichotomies – is moral enhancement feasible or unfeasible? Permissible or impermissible? Fact or fiction? On it goes. While these gesture at imperatives, trading in absolutes blurs the realities at hand. A sensible approach must resist extremes and recognize that moral disrupters are already here.
We know that existing interventions, whether they occur unknowingly or on purpose, have the power to modify moral dispositions in ways both good and bad. For instance, neurotoxins can promote antisocial behavior. The ‘lead-crime hypothesis’ links childhood lead-exposure to impulsivity, antisocial aggression, and various other problems. Mercury has been associated with cognitive deficits, which might impair moral reasoning and judgement. It’s well documented that alcohol makes people more prone to violence.
So, what about positive drivers? Here’s where it gets more tangled.
Medicine has long treated psychiatric disorders with drugs like sedatives and antipsychotics. However, there’s short mention of morality in the Diagnostic and Statistical Manual of Mental Disorders (DSM) despite the moral merits of pharmacotherapy – these effects are implicit and indirect. Such cases are regarded as treatments rather than enhancements.
It would be dangerously myopic to assume that moral augmentation is somehow beyond reach.
Conventionally, an enhancement must go beyond what is ‘normal,’ species-typical, or medically necessary – this is known as the ‘treatment-enhancement distinction.’ But boundaries of health and disease are fluid, so whether we call a procedure ‘moral enhancement’ or ‘medical treatment’ is liable to change with shifts in social values, expert opinions, and clinical practices.
Human enhancements are already used for a range of purported benefits: caffeine, smart drugs, and other supplements to boost cognitive performance; cosmetic procedures for aesthetic reasons; and steroids and stimulants for physical advantage. More boldly, cyborgs like Moon Ribas and Neil Harbisson are pushing transpecies boundaries with new kinds of sensory perception. It would be dangerously myopic to assume that moral augmentation is somehow beyond reach.
How might it work?
One possibility for shaping moral temperaments is with neurostimulation devices. These use electrodes to deliver a low-intensity current that alters the electromagnetic activity of specific neural regions. For instance, transcranial Direct Current Stimulation (tDCS) can target parts of the brain involved in self-awareness, moral judgement, and emotional decision-making. It’s been shown to increase empathy and valued-based learning, and decrease aggression and risk-taking behavior. Many countries already use tDCS to treat pain and depression, but evidence for enhancement effects on healthy subjects is mixed.
Another suggestion is targeting neuromodulators like serotonin and dopamine. Serotonin is linked to prosocial attributes like trust, fairness, and cooperation, but low activity is thought to motivate desires for revenge and harming others. It’s not as simple as indiscriminately boosting brain chemicals though. While serotonin is amenable to SSRIs, precise levels are difficult to measure and track, and there’s no scientific consensus on the “optimum” amount or on whether such a value even exists. Fluctuations due to lifestyle factors such as diet, stress, and exercise add further complexity. Currently, more research is needed on the significance of neuromodulators and their network dynamics across the moral landscape.
There are a range of other prospects. The ‘love drugs’ oxytocin and MDMA mediate pair bonding, cooperation, and social attachment, although some studies suggest that people with high levels of oxytocin are more aggressive toward outsiders. Lithium is a mood stabilizer that has been shown to reduce aggression in prison populations; beta-blockers like propranolol and the supplement omega-3 have similar effects. Increasingly, brain-computer interfaces augur a world of brave possibilities. Such appeals are not without limitations, but they indicate some ways that external tools can positively nudge our moral sentiments.
Who needs morally enhancing?
A common worry is that enhancement technologies could be weaponized for social control by authoritarian regimes, or used like the oppressive eugenics of the early 20th century. Fortunately, the realities are far more mundane and such dystopian visions are fantastical. So, what are some actual possibilities?
Some researchers suggest that neurotechnologies could help to reactivate brain regions of those suffering from moral pathologies, including healthy people with psychopathic traits (like a lack of empathy). Another proposal is using such technology on young people with conduct problems to prevent serious disorders in adulthood.
Most of us aren’t always as ethical as we would like – given the option of ‘priming’ yourself to act in consistent accord with your higher values, would you take it?
A question is whether these kinds of interventions should be compulsory for dangerous criminals. On the other hand, a voluntary treatment for inmates wouldn’t be so different from existing incentive schemes. For instance, some U.S. jurisdictions already offer drug treatment programs in exchange for early release or instead of prison time. Then there’s the difficult question of how we should treat non-criminal but potentially harmful ‘successful’ psychopaths.
Others argue that if virtues have a genetic component, there is no technological reason why present practices of embryo screening for genetic diseases couldn’t also be used for selecting socially beneficial traits.
Perhaps the most immediate scenario is a kind of voluntary moral therapy, which would use biomedicine to facilitate ideal brain-states to augment traditional psychotherapy. Most of us aren’t always as ethical as we would like – given the option of ‘priming’ yourself to act in consistent accord with your higher values, would you take it? Approaches like neurofeedback and psychedelic-assisted therapy could prove helpful.
What are the challenges?
A general challenge is that of setting. Morality is context dependent; what’s good in one environment may be bad in another and vice versa, so we don’t want to throw out the baby with the bathwater. Of course, common sense tells us that some tendencies are more socially desirable than others: fairness, altruism, and openness are clearly preferred over aggression, dishonesty, and prejudice.
One argument is that remoulding ‘brute impulses’ via biology would not count as moral enhancement. This view claims that for an action to truly count as moral it must involve cognition – reasoning, deliberation, judgement – as a necessary part of moral behavior. Critics argue that we should be concerned more with ends rather than means, so ultimately it’s outcomes that matter most.
Another worry is that modifying one biological aspect will have adverse knock-on effects for other valuable traits. Certainly, we must be careful about the network impacts of any intervention. But all stimuli have distributed effects on the body, so it’s really a matter of weighing up the cost/benefit trade-offs as in any standard medical decision.
Is it ethical?
Our values form a big part of who we are – some bioethicists argue that altering morality would pose a threat to character and personal identity. Another claim is that moral enhancement would compromise autonomy by limiting a person’s range of choices and curbing their ‘freedom to fall.’ Any intervention must consider the potential impacts on selfhood and personal liberty, in addition to the wider social implications.
This includes the importance of social and genetic diversity, which is closely tied to considerations of fairness, equality, and opportunity. The history of psychiatry is rife with examples of systematic oppression, like ‘drapetomania’ – the spurious mental illness that was thought to cause African slaves’ desire to flee captivity. Advocates for using moral enhancement technologies to help kids with conduct problems should be mindful that they disproportionately come from low-income communities. We must ensure that any habilitative practice doesn’t perpetuate harmful prejudices by unfairly targeting marginalized people.
Human capacities are the result of environmental influences, and external conditions still coax our biology in unknown ways. Status quo bias for ‘letting nature take its course’ may actually be worse long term – failing to utilize technology for human development may do more harm than good.
Then, there are concerns that morally-enhanced persons would be vulnerable to predation by those who deliberately avoid moral therapies. This relates to what’s been dubbed the ‘bootstrapping problem’: would-be moral enhancement candidates are the types of individuals that benefit from not being morally enhanced. Imagine if every senator was asked to undergo an honesty-boosting procedure prior to entering public office – would they go willingly? Then again, perhaps a technological truth-serum wouldn’t be such a bad requisite for those in positions of stern social consequence.
Advocates argue that biomedical moral betterment would simply offer another means of pursuing the same goals as fixed social mechanisms like religion, education, and community, and non-invasive therapies like cognitive-behavior therapy and meditation. It’s even possible that technological efforts would be more effective. After all, human capacities are the result of environmental influences, and external conditions still coax our biology in unknown ways. Status quo bias for ‘letting nature take its course’ may actually be worse long term – failing to utilize technology for human development may do more harm than good. If we can safely improve ourselves in direct and deliberate ways then there’s no morally significant difference whether this happens via conventional methods or new technology.
Future prospects
Where speculation about human enhancement has led to hype and technophilia, many bioethicists urge restraint. We can be grounded in current science while anticipating feasible medium-term prospects. It’s unlikely moral enhancement heralds any metamorphic post-human utopia (or dystopia), but that doesn’t mean dismissing its transformative potential. In one sense, we should be wary of transhumanist fervour about the salvatory promise of new technology. By the same token we must resist technofear and alarmist efforts to balk social and scientific progress. Emerging methods will continue to shape morality in subtle and not-so-subtle ways – the critical steps are spotting and scaffolding these with robust ethical discussion, public engagement, and reasonable policy options. Steering a bright and judicious course requires that we pilot the possibilities of morally-disruptive technologies.