New drug for schizophrenia could meet desperate need for better treatments
Schizophrenia is a debilitating mental health condition that affects around 24 million people worldwide. Patients experience hallucinations and delusions when they develop schizophrenia, with experts referring to these new thoughts and behaviors as positive symptoms. They also suffer from negative symptoms in which they lose important functions, suffering from dulled emotions, lack of purpose and social withdrawal.
Currently available drugs can control only a portion of these symptoms but, on August 8th, Karuna Therapeutics announced its completion of a phase 3 clinical trial that found a new drug called KarXT could treat both positive and negative symptoms of schizophrenia. It could mean substantial progress against a problem that has stymied scientists for decades.
A long-standing problem
Since the 1950s, antipsychotics have been used to treat schizophrenia. People who suffer from it are thought to have too much of a brain chemical called dopamine, and antipsychotics work by blocking dopamine receptors in the brain. They can be effective in treating positive symptoms but have little impact on the negative ones, which can be devastating for a patient’s quality of life, making it difficult to maintain employment and have successful relationships. About 30 percent of schizophrenia patients don't actually respond to antipsychotics at all. Current drugs can also have adverse side effects including elevated cholesterol, high blood pressure, diabetes and movements that patients cannot control.
The recent clinical trial heralds a new treatment approach. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” says Andrew Miller, COO of Karuna.
Scientists have been looking to develop alternatives. However, “the field of drug treatment of schizophrenia is currently in the doldrums,” says Peter McKenna, a senior researcher at FIDMAG Research Foundation in Spain which specialises in mental health.
In the 2000s there was a major push to target a brain receptor for a chemical called glutamate. Evidence suggested that this receptor is abnormal in the brains of schizophrenia patients, but attempts to try glutamate failed in clinical trials.
After that, many pharmaceutical companies dropped out of the race for a more useful treatment. But some companies continued to search, such as Karuna Therapeutics, led by founder and Chief Operating Officer Andrew Miller and CEO Steve Paul. The recent clinical trial suggests their persistence has led to an important breakthrough with their drug, KarXT. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” Miller says.
How it works
Neurotransmitters are chemical messengers that pass signals between neurons. To work effectively, neurotransmitters need a receptor to bind to. A neurotransmitter called acetylcholine seems to be especially important in schizophrenia. It interacts with sites called muscarinic receptors, which are involved in the network of nerves that calm your body after a stressful event. Post mortem studies in people with schizophrenia have shown that two muscarinic receptors in the brain, the M1 and M4 receptors, are activated at unusually low levels because they don’t receive enough signals from acetylcholine.
The M4 receptor appears to play a role in psychosis. The M1 receptor is also associated with psychosis but is primarily thought to be involved in cognition. KarXT, taken orally, works by activating both of these receptors to signal properly. It is this twofold action that seems to explain its effectiveness. “[The drug’s] design enables the preferential stimulation of these muscarinic receptors in the brain,” Miller says.
How it developed
It all started in the early 1990s when Paul was at pharmaceutical company Eli Lilly. He discovered that Xanomeline, the drug they were testing on Alzheimer's patients, had antipsychotic effects. It worked by stimulating M1 and M4 receptors, so he and his colleagues decided to test Xanomeline on schizophrenia patients, supported by research on the connection between muscarinic receptors and psychosis. They found that Xanomeline reduced both positive and negative symptoms.
Unfortunately, it also caused significant side effects. The problem was that stimulating the M1 and M4 receptors in the brain also stimulated muscarinic receptors in the body that led to severe vomiting, diarrhea and even the temporary loss of consciousness.
In the end, Eli Lilly discontinued the clinical trials for the drug, but Miller set up Karuna Therapeutics to develop a solution. “I was determined to find a way to harness the therapeutic benefit demonstrated in studies of Xanomeline, while eliminating side effects that limited its development,” Miller says.
He analysed over 7,000 possible ways of mixing Xanomeline with other agents before settling on KarXT. It combines Xanomeline with a drug called Trospium Chloride, which blocks muscarinic receptors in the body – taking care of the side effects such as vomiting – but leaves them unblocked in the brain. Paul was so excited by Miller’s progress that he joined Karuna after leaving Eli Lilly and founding two previous startups.
“It's a very important approach,” says Rick Adams, Future Leaders Fellow in the Institute of Cognitive Neuroscience and Centre for Medical Image Computing at University College London. “We are in desperate need of alternative drug targets and this target is one of the best. There are other alternative targets, but not many are as close to being successful as the muscarinic receptor drug.”
Clinical Trial
Following a successful phase 2 clinical trial in 2019, the most recent trial involved 126 patients who were given KarXT, and 126 who were given a placebo. Compared to the placebo, patients taking KarXT had a significant 9.6 point reduction in the positive and negative syndrome scale (PANSS), the standard for rating schizophrenic symptoms.
KarXT also led to statistically significant declines in positive and negative symptoms compared to the placebo. “The results suggest that KarXT could be a potentially game-changing option in the management of both positive and negative symptoms of schizophrenia,” Miller says.
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, is optimistic about the side effects but highlights the need for more safety trials.
McKenna, the researcher at FIDMAG Foundation, agrees about the drug’s potential. “The new [phase 3] study is positive,” he says. “It is reassuring that one is not dealing with a drug that works in one trial and then inexplicably fails in the next one.”
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, said the drug is an unprecedented step forward. “KarXT is one of the first drugs with a novel mechanism of action to show promise in clinical trials.”
Even though the drug blocks muscarine receptors in the body, some patients still suffered from adverse side effects like vomiting, dizziness and diarrhea. But in general, these effects were mild to moderate, especially compared to dopamine-blocking antipsychotics or Xanomeline on its own.
McCutcheon is optimistic about the side effects but highlights the need for more safety trials. “The trial results suggest that gastrointestinal side effects appear to be manageable,” he says. “We know, however, from previous antipsychotic drugs that the full picture regarding the extent of side effects can sometimes take longer to become apparent to clinicians and patients. Careful ongoing assessment during a longer period of treatment will therefore be important.”
The Future
The team is currently conducting three other trials to evaluate the efficacy and long-term safety of KarXT. Their goal is to receive FDA approval next year.
Karuna is also conducting trials to evaluate the effectiveness of KarXT in treating psychosis in patients suffering from Alzheimer’s.
The big hope is that they will soon be able to provide a radically different drug to help many patients with schizophrenia. “We are another step closer to potentially providing the first new class of medicine in more than 50 years to the millions of people worldwide living with schizophrenia,” says Miller.
It looks like an ordinary toilet but it is anything but. The "smart toilet" is the diagnostic tool of the future, equipped with cameras that take snapshots of the users and their waste, motion sensors to analyze what's inside the urine and stool samples, and software that automatically sends data to a secure, cloud-based system that can be easily accessed by your family doctor.
"It's a way of doing community surveillance. If there is a second wave of infections in the future, we'll know right away."
Using urine "dipstick tests" similar to the home pregnancy strips, the smart toilet can detect certain proteins, immune system biomarkers and blood cells that indicate the presence of such diseases as infections, bladder cancer, and kidney failure.
The rationale behind this invention is that some of the best ways of detecting what's going on in our bodies is by analyzing the substances we excrete every day, our sweat, urine, saliva and yes, our feces. Instead of getting sporadic snapshots from doctor's visits once or twice a year, the smart toilet provides continuous monitoring of our health 24/7, so we can catch the tell-tale molecular signature of illnesses at their earliest and most treatable stages. A brainchild of Stanford University researchers, they're now working to add a COVID-19 detection component to their suite of technologies—corona virus particles can be spotted in stool samples—and hope to have the system available within the year.
"We can connect the toilet system to cell phones so we'll know the results within 30 minutes," says Seung-min Park, a lead investigator on the research team that devised this technology and a senior research scientist at the Stanford University School of Medicine. "The beauty of this technology is that it can continuously monitor even after this pandemic is over. It's a way of doing community surveillance. If there is a second wave of infections in the future, we'll know right away."
Experts believe that the COVID-19 pandemic will accelerate the widespread acceptance of in-home diagnostic tools such as this. "Shock events" like pandemics can be catalysts for sweeping changes in society, history shows us. The Black Death marked the end of feudalism and ushered in the Renaissance while the aftershocks of the Great Depression and two world wars in the 20th century led to the social safety net of the New Deal and NATO and the European Union. COVID-19 could fundamentally alter the way we deliver healthcare, abandoning the outdated 20th century brick and mortar fee-for-service model in favor of digital medicine. At-home diagnostics may be the leading edge of this seismic shift and the pandemic could accelerate the product innovations that allow for home-based medical screening.
"That's the silver lining to this devastation," says Dr. Leslie Saxon, executive director of the USC Center for Body Computing at the Keck School of Medicine in Los Angeles. As an interventional cardiologist, Saxon has spent her career devising and refining the implantable and wearable wireless devices that are used to treat and diagnose heart conditions and prevent sudden death. "This will open up innovation—research has been stymied by a lack of imagination and marriage to an antiquated model," she adds. "There are already signs this is happening—relaxing state laws about licensure, allowing physicians to deliver health care in non-traditional ways. That's a real sea change and will completely democratize medical information and diagnostic testing."
Ironically, diagnostics have long been a step-child of modern medicine, even though accurate and timely diagnostics play a crucial role in disease prevention, detection and management. "The delivery of health care has proceeded for decades with a blind spot: diagnostic errors—inaccurate or delayed diagnoses—persist throughout all settings of care and continue to harm an unacceptable number of patients," according to a 2015 National Academy of Medicine report. That same report found as many as one out of five adverse events in the hospital result from these errors and they contribute to 10 percent of all patient deaths.
The pandemic should alter the diagnostic landscape. We already have a wealth of wearable and implantable devices, like glucose sensors to monitor blood sugar levels for diabetics, Apple's smart watch, electrocardiogram devices that can detect heart arrythmias, and heart pacemakers.
The Food and Drug Administration is working closely with in-home test developers to make accurate COVID-19 diagnostic tools readily available and has so far greenlighted three at-home collection test kits. Two, LabCorp's and Everlywell's, use nasal swabs to take samples. The third one is a spit test, using saliva samples, that was devised by a Rutgers University laboratory in partnership with Spectrum Solutions and Accurate Diagnostic Labs.
The only way to safely reopen is through large scale testing, but hospitals and doctors' offices are no longer the safest places.
In fact, DIY diagnostic company Everlywell, an Austin, Texas- based digital health company, already offers more than 30 at-home kits for everything from fertility to food sensitivity tests. Typically, consumers collect a saliva or finger-prick blood sample, dispatch it in a pre-paid shipping envelope to a laboratory, and a physician will review the results and send a report to consumers' smartphones.
Thanks to advances in technology, samples taken at home can now be preserved long enough to arrive intact at diagnostic laboratories. The key is showing the agency "transport and shipping don't change or interfere with the integrity of the samples," says Dr. Frank Ong, Everlywell's chief medical and scientific officer.
Ong is keenly aware of the importance of saturation testing because of the lessons learned by colleagues fighting the SARS pandemic in his family's native Taiwan in 2003. "In the beginning, doctors didn't know what they were dealing with and didn't protect themselves adequately," he says. "But over two years, they learned the hard way that there needs to be enough testing, contact tracing of those who have been exposed, and isolation of people who test positive. The value of at-home testing is that it can be done on the kind of broad basis that needs to happen for our country to get back to work."
Because of the pandemic, new policies have removed some of the barriers that impeded the widespread adoption of home-based diagnostics and telemedicine. Physicians can now practice across state lines, get reimbursed for telemedicine visits and use FaceTime to communicate with their patients, which had long been considered taboo because of privacy issues. Doctors and patients are becoming more comfortable and realizing the convenience and benefits of being able to do these things virtually.
Added to this, the only way to safely reopen for business without triggering a second and perhaps even more deadly wave of sickness is through large-scale testing, but hospitals and doctors' offices are no longer the safest places. "We don't want people sitting in a waiting room who later find out they're positive, and potentially infected everyone, including doctors and nurses," says Dr. Kavita Patel, a physician in Washington, DC who served as a policy director in the Obama White House.
In-home testing avoids the risks of direct exposure to the virus for both patients and health care professionals, who can dispense with cumbersome protective gear to take samples, and also enables people without reliable transportation or child-care to learn their status. "At home testing can be a critical component of our country's overall testing strategy," says Dr. Shantanu Nundy, chief medical officer at Accolade Health and on the faculty of the Milken Institute School of Public Health at George Washington University. "Once we're back at work, we need to be much more targeted, and have much more access to data and controlling those outbreaks as tightly as possible. The best way to do that is by leapfrogging clinics and being able to deliver tests at home for people who are disenfranchised by the current system."
In the not-too-distant future, in-home diagnostics could be a key component of precision medicine, which is customized care tailored specifically to each patient's individual needs. Like Stanford's smart toilet prototype, these ongoing surveillance tools will gather health data, ranging from exposures to toxins and pollutions in the environment to biochemical activity, like rising blood pressure, signs of inflammation, failing kidneys or tiny cancerous tumors, and provide continuous real-time information.
"These can be deeply personalized and enabled by smart phones, sensors and artificial intelligence," says USC's Leslie Saxon. "We'll be seeing the floodgates opening to patients accessing medical services through the same devices that they access other things, and leveraging these tools for our health and to fine tune disease management in a model of care that is digitally enabled."
[Editor's Note: This article was originally published on June 8th, 2020 as part of a standalone magazine called GOOD10: The Pandemic Issue. Produced as a partnership among LeapsMag, The Aspen Institute, and GOOD, the magazine is available for free online.]
Cleaning has taken on a whole new meaning in Frank Mosco's household during the COVID-19 pandemic. There's a protocol for everything he and his two teenage daughters do.
Experts agree that over-disinfecting is better than inadequate disinfecting, especially during a pandemic.
"We wipe down every package that comes into the house and the items inside," says Mosco, a technologist and social justice activist in Hastings-on-Hudson, N.Y. "If it's a fruit or vegetable, I use vinegar and water, or water and soap. Then we throw out the boxes, clean up the table, and wash our hands." Only then do they put items away.
As the novel coronavirus continues to pose an invisible threat, parents of infants to adolescents are pondering how vigorously and frequently to clean and disinfect surfaces at home and apply hand sanitizer in public. They also fret over whether there can be too much of a good thing: Will making everything as seemingly germ-free as possible reduce immunity down the road?
Experts agree that over-disinfecting is better than inadequate disinfecting, especially during a pandemic. Every family should assess their particular risks. Factors to consider include pre-existing medical conditions, the number of people living in the same home, and whether anyone works in a hospital or other virus-prone environment, says Kari Debbink, assistant professor of biology at Bowie State University in Bowie, Maryland.
Constantly cleaning everything in sight isn't necessary, she explains, because coronavirus tends to spread mainly via immediate contact with respiratory droplets—catching it from surfaces is a less-likely scenario. The longer the virus stays on a surface, the less contagious it becomes.
Some parents worry that their children's growing bodies may become accustomed to an environment that is "too clean." Debbink, a virologist, offers a salient reminder: "The immune system comes into contact with many, many different antigens every day, and it is 'trained' from birth onwards to respond to pathogens. Doing a little more cleansing and disinfecting during the pandemic will not weaken the immune system."
Other experts agree. "There should be no negative outcome to properly washing your hands more frequently," says Stacey Schultz-Cherry, an infectious diseases specialist at St. Jude Children's Research Hospital in Memphis, Tennessee. "Even with enhanced disinfection, kids are still getting exposed to immune-boosting microbes from playing outside, having pets, etc."
"There's no reason why hand sanitizer would weaken anyone's immune system of any age."
Applying hand sanitizer consisting of at least 60 percent alcohol helps clean hands while outdoors, says Angela Rasmussen, associate research scientist and a virologist at Columbia University's Mailman School of Public Health in New York. "There's no reason why hand sanitizer would weaken anyone's immune system of any age," she adds, and recommends moisturizer so hands don't dry out from frequent use. Meanwhile, "cleaning and disinfecting at home also don't have an impact on antiviral immunity, in kids or adults."
With the coronavirus foremost in parents' minds, Patricia Garcia, a pediatric hospitalist, has fielded many questions about how thoroughly they should wipe, rub, scrub, or mop. As medical director of Connecticut Children's Healthy Homes Program in Hartford, which takes aim at toxins and other housing hazards, she reassures them with this mantra: "You're never going to get it perfectly sterilized, and that's okay."
To quell some of these concerns, in March the U.S. Environmental Protection Agency (EPA) released a list of products for household use. None of these products have been specifically tested against SARS-CoV-2, the novel coronavirus that causes COVID-19. But the agency expects these products to be effective because they have demonstrated efficacy against a different human coronavirus similar to SARS-CoV-2 or an even harder-to-kill virus.
Many products on the list contain isopropyl alcohol or hydrogen peroxide. "When using an EPA-registered disinfectant," the agency's website instructs, "follow the label directions for safe, effective use. Make sure to follow the contact time, which is the amount of time the surface should be visibly wet."
Bear in mind that not all cleaners actually disinfect, cautions Alan Woolf, a pediatrician at Boston Children's Hospital who directs its environmental health center and is a professor at Harvard Medical School. Some cleaners remove visible dirt, grease, and grime, but they don't kill viruses. Disinfectants by their nature inactivate both bacteria and viruses. "That's an important distinction," Woolf says.
Frequently touched surfaces—for instance, doorknobs, light switches, toilet-flushing levers, and countertops—should not only be cleaned, but also disinfected at least daily during a pandemic if someone in the household is sick. The objects one touches upon coming home are the ones most likely to become contaminated with viruses, experts say.
Before bringing items inside, "it might be good to clear off a counter space where they will be placed," says Debbink, the biology professor and virologist. "This way, they come into contact with as few items and surfaces as possible."
If space permits, another option would be to set aside nonperishable items. "I've heard of some families putting things in a 'mud room' and closing the door for 48 hours, some leaving things in their garage or car trunk," says Stephanie Holm, co-director of the Western States Pediatric Environmental Health Specialty Unit at the University of California, San Francisco. "Letting new purchases sit for 48 hours undisturbed would greatly reduce the number of viable viruses present."
Cleaning surfaces is recommended before disinfecting them. Holm suggests using unscented soap and microfiber cloths instead of paper towels, which can transmit bacteria and viruses from one area to another.
Soap has the power to eradicate viruses with at least 20 seconds of contact time. It attacks the coronavirus's protective coat, explains infectious diseases specialist Schultz-Cherry. "If you destroy the coat, the virus is no longer infectious. Influenza virus is also very sensitive to soap."
"The most important thing that parents should do for children's immune systems is make sure they are up to date on all their vaccines."
For cribs, toys, and other mouth-contact surfaces, sanitizing with soap and water, not disinfectants, is advisable, says pediatrician Woolf. Fresh fruits and vegetables also can be cleaned with soap, removing dirt and pesticide residue, he adds.
"Some parents are nervous about using disinfectant on toys, which is understandable, considering many toys end up in children's mouths, so soap and water can be an alternative," says pediatrician Garcia, who recommends using hot water.
While some toys can go in the washing machine and dryer or dishwasher, others need to be cleaned by hand, with dish soap or a delicate detergent, as indicated on their labels. But toys with electrical components cannot be submerged in water, in which case consulting the EPA's list of disinfectants may be a parent's best option, she says.
Labels on the back of cleaning and disinfecting products also contain specific instructions. Not allowing a liquid to sit on a surface for the recommended time results in exposure to chemicals without even accomplishing the intended purpose of disinfection. For most household bleach-containing agents, the advisable "dwell time" is 10 minutes. "Many people don't realize this," says Holm, the environmental health specialist who also trained as a physician.
Beware of combining any type of cleaners or disinfectants that aren't already premixed. Doing so can release harmful gases into the air, she cautions.
During the pandemic, Mosco and his daughters have been very conscientious about decontaminating whatever comes through their doors. Mosco says he doesn't believe the family is overusing cleaning and disinfecting products. Although he's fastidious, he says, "a completely sterile environment is not the goal."
His mother, who was a nurse, instilled in him that exposure to some bacteria is a good thing. In turn, he "always encouraged his kids to play with animals, and to have fun in sand and dirt, with plenty of sunlight to keep their immune systems strong."
Even though a vaccine for coronavirus currently doesn't exist, parents can take some comfort in the best weapon available today to protect kids from deadly pathogens: "The most important thing that parents should do for children's immune systems," says virologist Rasmussen, "is make sure they are up to date on all their vaccines."