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.”
More Families Are Using Nanny Cams to Watch Elderly Loved Ones, Raising Ethical Questions
Jackie Costanzo and her 93-year-old mom, Louise, are happy to have an extra way to stay connected with the camera, which is normally placed on a television stand facing her mom's bed.
After Jackie Costanzo's mother broke her right hip in a fall, she needed more hands-on care in her assisted-living apartment near Sacramento, California. A social worker from her health plan suggested installing a video camera to help ensure those services were provided.
Without the camera, Costanzo wouldn't have a way to confirm that caregivers had followed through with serving meals, changing clothes, and fulfilling other care needs.
When Costanzo placed the device in May 2018, she informed the administrator and staff, and at first, there were no objections. The facility posted a sign on the apartment's front door, alerting anyone who entered of recording in progress.
But this past spring, a new management company came across the sign and threatened to issue a 30-day eviction notice to her 93-year-old mother, Louise Munch, who has dementia, for violating a policy that prohibits cameras in residents' rooms. With encouragement from California Advocates for Nursing Home Reform, Costanzo researched the state's regulations but couldn't find anything to support or deny camera use. She refused to remove the recording device and prevailed.
"In essence, my mom was 'grandfathered in' because she moved in under a management company that did not specify that residents could not have cameras," says Costanzo, 73, a retired elementary schoolteacher who lives a three-hour drive away, in Silicon Valley, and visits one day every two weeks. Without the camera, Costanzo, who is her mother's only surviving child, wouldn't have a way to confirm that caregivers had followed through with serving meals, changing clothes, and fulfilling other care needs.
As technological innovations enable next of kin to remain apprised of the elderly's daily care in long-term care facilities, surveillance cameras bring legal and privacy issues to the forefront of a complex ethical debate. Families place them overtly or covertly—disguised in a makeshift clock radio, for instance—when they suspect or fear abuse or neglect, so they can maintain a watchful eye, perhaps deterring egregious behavior. But the cameras also capture intimate caregiving tasks, such as bathing and toileting, as well as dressing and undressing, which may undermine the dignity of residents.
So far, laws or guidelines in eight states—Illinois, Maryland, New Mexico, Oklahoma, Texas, Utah, Virginia, and Washington—have granted families the rights to install cameras in a resident's room. In addition, about 15 other states have proposed legislation. Some states, such as Pennsylvania, have put forth regulatory compliance guidance, according to a column published in the July/August 2018 issue of Annals of Long-Term Care.
The increasing prevalence of this legislation has placed it on the radar of long-term care providers. It also suggests a trend to clarify responsible camera use in monitoring services while respecting privacy, says Victor Lane Rose, the column's editor and director of aging services at ECRI Institute, a health care nonprofit near Philadelphia, Pennsylvania.
In most cases, a resident's family installs a camera or instigates a request in hopes of sparing their loved one from the harms of abuse, says James Wright, a family physician who serves as the ethics committee's vice chair of the Society for Post-Acute and Long-Term Care Medicine in Columbia, Maryland. A camera also allows the family to check in on the resident from afar and remain on alert for a potential fall or agitated state, he says.
"It's rare that a facility will have 24-hour presence in a patient's room. You won't have a nurse in there all the time," says Wright, who is also medical director of two long-term care centers and one assisted-living facility around Richmond, Virginia. Particularly "with dementia, the family often wonders" if their loved one is safe.
While offering families peace of mind, he notes that video cameras can also help exonerate caregivers accused of abuse or theft. Hearing aids, which typically cost between $2,000 and $3,000 each, often go missing. By reviewing a video together, families and administrators may find clues to a device's disappearance. Conversely, Wright empathizes with the main counterargument against camera use, which is the belief that "invasion of privacy is also invasion of human dignity."
In respecting modesty, ethical questions abound over whether a camera should be turned off when a patient is in the midst of receiving personal care, such as dressing and undressing or using bedpans. Other ethical issues revolve around who may access the recordings, says Lori Smetanka, executive director of the National Consumer Voice for Quality Long-Term Care in Washington, D.C.
Video cameras, she contends, are only one tool in shielding residents from abuse. They are "not substitutes for personal involvement," she says. "People need to be very vigilant visiting their family members, and facilities have a responsibility to ensure that residents are free of abuse."
Lack of accountability perpetuates abuse in long-term care settings and stems in large part from systemic underfunding.
Educating employees in abuse prevention becomes paramount, and families should ask about staff training before placing their loved one in a long-term care facility, Smetanka says. Prior to installing a camera, she recommends consulting an attorney who is familiar with this issue.
But thoughts of a camera often don't occur to families until an adverse event affects their loved one, says Toby Edelman, a senior policy attorney at the Center for Medicare Advocacy, a nonprofit organization with headquarters in Washington, D.C., and Connecticut.
"These cameras can show exactly what's going on," she explains, noting that prosecutors have used the recordings in litigation. "When residents have injuries of unknown origin" and they can't verbalize what happened to them, "the cameras may document that yes, the resident was actually hit by somebody."
With a resident's safety and security being "the most important consideration," the American Health Care Association in Washington, D.C., which represents long-term and post-acute care providers, supports allowing states, clinicians, and patients to decide about camera use on a local level, says David Gifford, senior vice president of quality and regulatory affairs and chief medical officer.
"We've seen some success with tools such as permissive legislation, where residents and their loved ones have the ability to determine whether a camera is right for them while working with the center openly and ensuring the confidentiality of other residents," says Gifford, who practiced as a geriatrician. "It is important to note, however, that surveillance cameras are still only one element of the quality matrix. We can never hope to truly improve quality care by catching bad actors after the fact."
Lack of accountability perpetuates abuse in long-term care settings and stems in large part from systemic underfunding. Low wages and morale are tied to high turnover, and cameras don't address this overarching problem, says Clara Berridge, an assistant professor of social work at the University of Washington in Seattle, who has co-authored articles on surveillance devices in elder care.
Employees often don't perceive a nursing assistant position as a long-term career trajectory and may not feel vested in the workplace. Training in the recognition and reporting of abuse becomes ineffective when workers quit shortly thereafter. Many must juggle multiple jobs to make ends meet. Staffing shortages are endemic, leading to inadequate oversight of residents and voicing of abuse complaints, she says.
In Berridge's assessment, cameras may do more harm than good. Respondents to a survey she conducted of nursing homes and assisted-living facilities in the United States found that recording devices tend to fuel workers' anxiety amid a culture that further demoralizes and dehumanizes the care they provide.
Consent becomes particularly thorny in shared rooms, which are more common than not in nursing homes. States that permit in-room cameras mandate that roommates or their legal representative be made aware. Even if the camera is directed away from their bed, it will still capture conversations as well as movements that enter its scope. "Surveillance isn't the best way to protect adults in need of support," Berridge says. "Public investment in quality care is."
"The camera is invaluable. But there's no law that says you can have it automatically, so that's wrong."
In the one-bedroom assisted-living apartment where Costanzo's mother lives alone, consent from another resident wasn't needed. Without a roommate, the camera is much less intrusive, although Costanzo wishes she had put one in the living room, not just the bedroom, for more security.
Her safety concerns escalated when she read about a Texas serial killer who smothered victims after gaining access to senior care facilities by "masquerading as a maintenance man." She points to such horrifying incidents, although exceedingly rare, as further justification for permitting cameras to help guard the vulnerable against abuse in long-term care settings. And she hopes to advocate for an applicable law in California.
"The camera is invaluable," says Costanzo, who pays for monthly Wi-Fi service so she can see and interact with her mother, who turns 94 in October, any time of day or night. "But there's no law that says you can have it automatically, so that's wrong."
Scientists Used Fruit Flies to Quickly Develop a Personalized Cancer Treatment for a Dying Man
Genetically engineered fruit flies are being used in early research to screen novel combinations of cancer drugs for individual patients.
Imagine a man with colorectal cancer that has spread throughout his body. His tumor is not responding to traditional chemotherapy. He needs a radically effective treatment as soon as possible and there's no time to wait for a new drug or a new clinical trial.
A plethora of novel combinations of treatments can be screened quickly on as many as 400,000 flies at once.
This was the very real, and terrifying, situation of a recent patient at Mount Sinai Medical Center in New York City. So his doctors turned to a new tactic to speed up the search for a treatment that would save him: Fruit flies.
Yes, fruit flies. Those annoying little buggers that descend on opened food containers are actually leading scientists to fully personalized cancer treatments. Oncology advances often are more about about utilizing old drugs in new combinations than about adding new drugs. But classically, the development of each new chemotherapy drug combination has required studies involving numerous patients spread over many years or decades.
With the fruit fly method, however, a novel treatment -- in the sense that a particular combination of drugs and the timing of their administration has never been used before -- is developed for each patient, almost like on Star Trek, when, faced suddenly with an unknown disease, a futuristic physician researches it and develops a cure quickly enough to save the patient's life.
How It Works
Using genetic engineering techniques, researchers produce a population of fruit fly embryos, each of which is programmed to develop a replica of the patient's cancer.
Since a lot of genetically identical fly embryos can be created, and since they hatch from eggs within 30 hours and then mature within days, a plethora of novel combinations of treatments can be screened quickly on as many as 400,000 flies at once. Then, only the regimens that are effective are administered to the patient.
Biotech entrepreneur Laura Towart, CEO of the UK- and Ireland-based company, My Personal Therapeutics, is partnering with Mount Sinai to develop and test the fruit fly tactic. The researchers recently published a paper demonstrating that the tumor of the man with metastatic colorectal cancer had shrunk considerably following the treatment, and remained stable for 11 months, although he eventually succumbed to his illness.
Open Questions
Cancer is in fact many different diseases, even if it strikes two people in the same place, and both cancers look the same under a microscope. At the level of DNA, RNA, proteins, and other molecular factors, each cancer is unique – and may require a unique treatment approach.
Determining the true impact on cancer mortality will require clinical trials involving many more patients.
"Anatomy of a cancer still plays a major role, if you're a surgeon or radiation oncologist, but the medical approach to cancer therapy is moving toward treatments that are personalized based on other factors," notes Dr. Howard McLeod, an internationally recognized expert on cancer genetics at the Moffitt Cancer Center, in Tampa, Florida. "We are also headed into an era when even the methods for monitoring patients are individualized."
One big unresolved question about the fruit fly screening approach is how effective it will be in terms of actually extending life. Determining the true impact on cancer mortality will require clinical trials involving many more patients.
Next Up
Using machine learning and artificial intelligence, Towart is now working to build a service called TuMatch that will offer rapid and affordable personalized treatment recommendations for all genetically driven cancers. "We hope to have TuMatch available to patients with colorectal/GI cancers by January 2020," she says. "We are also offering [the fruit fly approach] for patients with rare genetic diseases and for patients who are diabetic."
Are Towart's fruit flies the answer to why the man's tumor shrunk? To be sure, the definitive answer will come from further research that is expected soon, but it's also clear that, prior to the treatment, there was nothing left to do for that particular patient. Thus, although it's early in the game, there's a pretty good rationale for optimism.