New drug for schizophrenia could meet desperate need for better treatments
The field of treating schizophrenia with drugs has been stuck in a long drought but, this month, a late-stage clinical trial found a new drug called KarXT could treat a range of symptoms.
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.
How Excessive Regulation Helped Ignite COVID-19's Rampant Spread
Screenshot of an interactive map of coronavirus cases across the United States, current as of 1:45 p.m. Pacific time on Tuesday, March 31st. Full map accessible at https://coronavirus.jhu.edu/map.html
When historians of the future look back at the 2020 pandemic, the heroic work of Helen Y. Chu, a flu researcher at the University of Washington, will be worthy of recognition.
Chu's team bravely defied the order and conducted the testing anyway.
In late January, Chu was testing nasal swabs for the Seattle Flu Study to monitor influenza spread when she learned of the first case of COVID-19 in Washington state. She deemed it a pressing public health matter to document if and how the illness was spreading locally, so that early containment efforts could succeed. So she sought regulatory approval to adapt the Flu Study to test for the coronavirus, but the federal government denied the request because the original project was funded to study only influenza.
Aware of the urgency, Chu's team bravely defied the order and conducted the testing anyway. Soon they identified a local case in a teenager without any travel history, followed by others. Still, the government tried to shutter their efforts until the outbreak grew dangerous enough to command attention.
Needless testing delays, prompted by excessive regulatory interference, eliminated any chances of curbing the pandemic at its initial stages. Even after Chu went out on a limb to sound alarms, a heavy-handed bureaucracy crushed the nation's ability to roll out early and widespread testing across the country. The Centers for Disease Control and Prevention infamously blundered its own test, while also impeding state and private labs from coming on board, fueling a massive shortage.
The long holdup created "a backlog of testing that needed to be done," says Amesh Adalja, an infectious disease specialist who is a senior scholar at the Johns Hopkins University Center for Health Security.
In a public health crisis, "the ideal situation" would allow the government's test to be "supplanted by private laboratories" without such "a lag in that transition," Adalja says. Only after the eventual release of CDC's test could private industry "begin in earnest" to develop its own versions under the Food and Drug Administration's emergency use authorization.
In a statement, CDC acknowledged that "this process has not gone as smoothly as we would have liked, but there is currently no backlog for testing at CDC."
Now, universities and corporations are in a race against time, playing catch up as the virus continues its relentless spread, also afflicting many health care workers on the front lines.
"Home-testing accessibility is key to preventing further spread of the COVID-19 pandemic."
Hospitals are attempting to add the novel coronavirus to the testing panel of their existent diagnostic machines, which would reduce the results processing time from 48 hours to as little as four hours. Meanwhile, at least four companies announced plans to deliver at-home collection tests to help meet the demand – before a startling injunction by the FDA halted their plans.
Everlywell, an Austin, Texas-based digital health company, had been set to launch online sales of at-home collection kits directly to consumers last week. Scaling up in a matter of days to an initial supply of 30,000 tests, Everlywell collaborated with multiple laboratories where consumers could ship their nasal swab samples overnight, projecting capacity to screen a quarter-million individuals on a weekly basis, says Frank Ong, chief medical and scientific officer.
Secure digital results would have been available online within 48 hours of a sample's arrival at the lab, as well as a telehealth consultation with an independent, board-certified doctor if someone tested positive, for an inclusive $135 cost. The test has a less than 3 percent false-negative rate, Ong says, and in the event of an inadequate self-swab, the lab would not report a conclusive finding. "Home-testing accessibility," he says, "is key to preventing further spread of the COVID-19 pandemic."
But on March 20, the FDA announced restrictions on home collection tests due to concerns about accuracy. The agency did note "the public health value in expanding the availability of COVID-19 testing through safe and accurate tests that may include home collection," while adding that "we are actively working with test developers in this space."
After the restrictions were announced, Everlywell decided to allocate its initial supply of COVID-19 collection kits to hospitals, clinics, nursing homes, and other qualifying health care companies that can commit to no-cost screening of frontline workers and high-risk symptomatic patients. For now, no consumers can order a home-collection test.
"Losing two months is close to disastrous, and that's what we did."
Currently, the U.S. has ramped up to testing an estimated 100,000 people a day, according to Stat News. But 150,000 or more Americans should be tested every day, says Ashish Jha, professor and director of the Harvard Global Health Institute. Due to the dearth of tests, many sick people who suspect they are infected still cannot get confirmation unless they need to be hospitalized.
To give a concrete sense of how far behind we are in testing, consider Palm Beach County, Fla. The state's only drive-thru test center just opened there, requiring an appointment. The center aims to test 750 people per day, but more than 330,000 people have already called to try to book a slot.
"This is such a rapidly moving infection that losing a few days is bad, and losing a couple of weeks is terrible," says Jha, a practicing general internist. "Losing two months is close to disastrous, and that's what we did."
At this point, it will take a long time to fully ramp up. "We are blindfolded," he adds, "and I'd like to take the blindfolds off so we can fight this battle with our eyes wide open."
Better late than never: Yesterday, FDA Commissioner Stephen Hahn said in a statement that the agency has worked with more than 230 test developers and has approved 20 tests since January. An especially notable one was authorized last Friday – 67 days since the country's first known case in Washington state. It's a rapid point-of-care test from medical-device firm Abbott that provides positive results in five minutes and negative results in 13 minutes. Abbott will send 50,000 tests a day to urgent care settings. The first tests are expected to ship tomorrow.
Your Privacy vs. the Public's Health: High-Tech Tracking to Fight COVID-19 Evokes Orwell
Governments around the world are using technology to track their citizens to contain COVID-19.
The COVID-19 pandemic has placed public health and personal privacy on a collision course, as smartphone technology has completely rewritten the book on contact tracing.
It's not surprising that an autocratic regime like China would adopt such measures, but democracies such as Israel have taken a similar path.
The gold standard – patient interviews and detective work – had been in place for more than a century. It's been all but replaced by GPS data in smartphones, which allows contact tracing to occur not only virtually in real time, but with vastly more precision.
China has gone the furthest in using such tech to monitor and prevent the spread of the coronavirus. It developed an app called Health Code to determine which of its citizens are infected or at risk of becoming infected. It has assigned each individual a color code – red, yellow or green – and restricts their movement depending on their assignment. It has also leveraged its millions of public video cameras in conjunction with facial recognition tech to identify people in public who are not wearing masks.
It's not surprising that an autocratic regime like China would adopt such measures, but democracies such as Israel have taken a similar path. The national security agency Shin Bet this week began analyzing all personal cellphone data under emergency measures approved by the government. It texts individuals when it's determined they had been in contact with someone who had the coronavirus. In Spain and China, police have sent drones aloft searching for people violating stay-at-home orders. Commands to disperse can be issued through audio systems built into the aircraft. In the U.S., efforts are underway to lift federal restrictions on drones so that police can use them to prevent people from gathering.
The chief executive of a drone manufacturer in the U.S. aptly summed up the situation in an interview with the Financial Times: "It seems a little Orwellian, but this could save lives."
Epidemics and how they're surveilled often pose thorny dilemmas, according to Craig Klugman, a bioethicist and professor of health sciences at DePaul University in Chicago. "There's always a moral issue to contact tracing," he said, adding that the issue doesn't change by nation, only in the way it's resolved.
"Once certain privacy barriers have been breached, it can be difficult to roll them back again."
In China, there's little to no expectation for privacy, so their decision to take the most extreme measures makes sense to Klugman. "In China, the community comes first. In the U.S., individual rights come first," he said.
As the U.S. has scrambled to develop testing kits and manufacture ventilators to identify potential patients and treat them, individual rights have mostly not received any scrutiny. However, that could change in the coming weeks.
The American approach is also leaning toward using smartphone apps, but in a way that may preserve the privacy of users. Researchers at MIT have released a prototype known as Private Kit: Safe Paths. Patients diagnosed with the coronavirus can use the app to disclose their location trail for the prior 28 days to other users without releasing their specific identity. They also have the option of sharing the data with public health officials. But such an app would only be effective if there is a significant number of users.
Singapore is offering a similar app to its citizens known as TraceTogether, which uses both GPS and Bluetooth pings among users to trace potential encounters. It's being offered on a voluntary basis.
The Electronic Frontier Foundation, the leading nonprofit organization defending civil liberties in the digital world, said it is monitoring how these apps are developed and deployed. "Governments around the world are demanding new dragnet location surveillance powers to contain the COVID-19 outbreak," it said in a statement. "But before the public allows their governments to implement such systems, governments must explain to the public how these systems would be effective in stopping the spread of COVID-19. There's no questioning the need for far-reaching public health measures to meet this urgent challenge, but those measures must be scientifically rigorous, and based on the expertise of public health professionals."
Andrew Geronimo, director of the intellectual property venture clinic at the Case Western University School of Law, said that the U.S. government is currently in talks with Facebook, Google and other tech companies about using deidentified location data from smartphones to better monitor the progress of the outbreak. He was hesitant to endorse such a step.
"These companies may say that all of this data is anonymized," he said, "but studies have shown that it is difficult to fully anonymize data sets that contain so much information about us."
Beyond the technical issues, social attitudes may mount another challenge. Epic events such as 9/11 tend to loosen vigilance toward protecting privacy, according to Klugman and Geronimo. And as more people are sickened and hospitalized in the U.S. with COVID-19, Klugman believes more Americans will be willing to allow themselves to be tracked. "If that happens, there needs to be a time limitation," he said.
However, even if time limits are put in place, Geronimo believes it would lead to an even greater rollback of privacy during the next crisis.
"Once certain privacy barriers have been breached, it can be difficult to roll them back again," he warned. "And the prior incidents could always be used as a precedent – or as proof of concept."