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.
The Nation’s Science and Health Agencies Face a Credibility Crisis: Can Their Reputations Be Restored?
Morale at federal science agencies -- and public trust in their guidance -- is at a concerning low right now.
This article is part of the magazine, "The Future of Science In America: The Election Issue," co-published by LeapsMag, the Aspen Institute Science & Society Program, and GOOD.
It didn't have to be this way. More than 200,000 Americans dead, seven million infected, with numbers continuing to climb, an economy in shambles with millions out of work, hundreds of thousands of small businesses crushed with most of the country still under lockdown. And all with no end in sight. This catastrophic result is due in large part to the willful disregard of scientific evidence and of muzzling policy experts by the Trump White House, which has spent its entire time in office attacking science.
One of the few weapons we had to combat the spread of Covid-19—wearing face masks—has been politicized by the President, who transformed this simple public health precaution into a first amendment issue to rally his base. Dedicated public health officials like Dr. Anthony Fauci, the highly respected director of the National Institute of Allergies and Infectious Diseases, have received death threats, which have prompted many of them around the country to resign.
Over the summer, the Trump White House pressured the Centers for Disease Control, which is normally in charge of fighting epidemics, to downplay COVID risks among young people and encourage schools to reopen. And in late September, the CDC was forced to pull federal teams who were going door-to-door doing testing surveys in Minnesota because of multiple incidents of threats and abuse. This list goes on and on.
Still, while the Trump administration's COVID failures are the most visible—and deadly—the nation's entire federal science infrastructure has been undermined in ways large and small.
The White House has steadily slashed monies for science—the 2021 budget cuts funding by 10–30% or more for crucial agencies like National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA)—and has gutted health and science agencies across the board, including key agencies of the Department of Energy and the Interior, especially in divisions that deal with issues they oppose ideologically like climate change.
Even farmers can't get reliable information about how climate change affects planting seasons because the White House moved the entire staff at the U.S. Department of Agriculture agency who does this research, relocating them from Maryland to Kansas City, Missouri. Many of these scientists couldn't uproot their families and sell their homes, so the division has had to pretty much start over from scratch with a skeleton crew.
More than 1,600 federal scientists left government in the first two years of the Trump Administration, according to data compiled by the Washington Post, and one-fifth of top positions in science are vacant, depriving agencies of the expertise they need to fulfill their vital functions. Industry executives and lobbyists have been installed as gatekeepers—HHS Secretary Alex Azar was previously president of Eli Lilly, and three climate change deniers were appointed to key posts at the National Oceanic and Atmospheric Administration, to cite just a couple of examples. Trump-appointed officials have sidelined, bullied, or even vilified those who dare to speak out, which chills the rigorous debate that is the essential to sound, independent science.
"The CDC needs to be able to speak regularly to the American people to explain what it knows and how it knows it."
Linda Birnbaum knows firsthand what it's like to become a target. The microbiologist recently retired after more than a decade as the director of the National Institute of Environmental Health Sciences, which is the world's largest environmental health organization and the greatest funder of environmental health and toxicology research, a position that often put her agency at odds with the chemical and fossil fuel industry. There was an attempt to get her fired, she says, "because I had the nerve to write that science should be used in making policy. The chemical industry really went after me, and my last two years were not so much fun under this administration. I'd like to believe it was because I was making a difference—if I wasn't, they wouldn't care."
Little wonder that morale at federal agencies is low. "We're very frustrated," says Dr. William Schaffner, a veteran infectious disease specialist and a professor of medicine at the Vanderbilt University School of Medicine in Nashville. "My colleagues within these agencies, the CDC rank and file, are keeping their heads down doing the best they can, and they hope to weather this storm."
The cruel irony is that the United States was once a beacon of scientific innovation. In the heady post World War II years, while Europe lay in ruins, the successful development of penicillin and the atomic bomb—which Americans believed helped vanquish the Axis powers—unleashed a gusher of public money into research, launching an unprecedented era of achievement in American science. Scientists conquered polio, deciphered the genetic code, harnessed the power of the atom, invented lasers, transistors, microchips and computers, sent missions beyond Mars, and landed men on the moon. A once-inconsequential hygiene laboratory was transformed into the colossus the National Institutes of Health has become, which remains today the world's flagship medical research center, unrivaled in size and scope.
At the same time, a tiny public health agency headquartered in Atlanta, which had been in charge of eradicating the malaria outbreaks that plagued impoverished rural areas in the Deep South until the late 1940s, evolved into the Centers for Disease Control and Prevention. The CDC became the world's leader in fighting disease outbreaks, and the agency's crack team of epidemiologists—members of the vaunted Epidemic Intelligence Service—were routinely dispatched to battle global outbreaks of contagions such as Ebola and malaria and help lead the vaccination campaigns to eradicate killers like polio and small pox that have saved millions of lives.
What will it take to rebuild our federal science infrastructure and restore not only the public's confidence but the respect of the world's scientific community? There are some hopeful signs that there is pushback against the current national leadership, and non-profit watchdog groups like the Union of Concerned Scientists have mapped out comprehensive game plans to restore public trust and the integrity of science.
These include methods of protecting science from political manipulation; restoring the oversight role of independent federal advisory committees, whose numbers were decimated by recent executive orders; strengthening scientific agencies that have been starved by budget cuts and staff attrition; and supporting whistleblower protections and allowing scientists to do their jobs without political meddling to restore integrity to the process. And this isn't just a problem at the CDC. A survey of 1,600 EPA scientists revealed that more than half had been victims of political interference and were pressured to skew their findings, according to research released in April by the Union of Concerned Scientists.
"Federal agencies are staffed by dedicated professionals," says Andrew Rosenberg, director of the Center for Science and Democracy at the Union of Concerned Scientists and a former fisheries biologist for NOAA. "Their job is not to serve the president but the public interest. Inspector generals are continuing to do what they're supposed to, but their findings are not being adhered to. But they need to hold agencies accountable. If an agency has not met its mission or engaged in misconduct, there needs to be real consequences."
On other fronts, last month nine vaccine makers, including Sanofi, Pfizer, and AstraZeneca, took the unprecedented stop of announcing that their COVID-19 vaccines would be thoroughly vetted before they were released. In their implicit refusal to bow to political pressure from the White House to have a vaccine available before the election, their goal was to restore public confidence in vaccine safety, and ensure that enough Americans would consent to have the shot when it was eventually approved so that we'd reach the long-sought holy grail of herd immunity.
"That's why it's really important that all of the decisions need to be made with complete transparency and not taking shortcuts," says Dr. Tom Frieden, president and CEO of Resolve to Save Lives and former director of the CDC during the H1N1, Ebola, and Zika emergencies. "A vaccine is our most important tool, and we can't break that tool by meddling in the science approval process."
In late September, Senate Democrats introduced a new bill to halt political meddling in public health initiatives by the White House. Called Science and Transparency Over Politics Act (STOP), the legislation would create an independent task force to investigate political interference in the federal response to the coronavirus pandemic. "The Trump administration is still pushing the president's political priorities rather than following the science to defeat this virus," Senate Minority Leader Chuck Schumer said in a press release.
To effectively bring the pandemic under control and restore public confidence, the CDC must assume the leadership role in fighting COVID-19. During previous outbreaks, the top federal infectious disease specialists like Drs. Fauci and Frieden would have daily press briefings, and these need to resume. "The CDC needs to be able to speak regularly to the American people to explain what it knows and how it knows it," says Frieden, who cautions that a vaccine won't be a magic bullet. "There is no one thing that is going to make this virus go away. We need to continue to limit indoor exposures, wear masks, and do strategic testing, isolation, and quarantine. We need a comprehensive approach, and not just a vaccine."
We must also appoint competent and trustworthy leaders, says Rosenberg of the Union of Concerned Scientists. Top posts in too many science agencies are now filled by former industry executives and lobbyists with a built-in bias, as well as people lacking relevant scientific experience, many of whom were never properly vetted because of the current administration's penchant for bypassing Congress and appointing "acting" officials. "We've got great career people who have hung in, but in so much of the federal government, they just put in 'acting' people," says Linda Birnbaum. "They need to bring in better, qualified senior leadership."
Open positions need to be filled, too. Federal science agencies have been seriously crippled by staffing attrition, and the Trump Administration instituted a hiring freeze when it first came in. Staffing levels remain at least ten percent down from previous levels, says Birnbaum and in many agencies, like the EPA, "everything has come to a screeching halt, making it difficult to get anything done."
But in the meantime, the critical first step may be at the ballot box in November. Even Scientific American, the esteemed consumer science publication, for the first time in its 175-year history felt "compelled" to endorse a presidential candidate, Joe Biden, because of the enormity of the damage they say Donald Trump has inflicted on scientists, their legal protections, and on the federal science agencies.
"If the current administration continues, the national political leadership will be emboldened and will be even more assertive of their executive prerogatives and less concerned about traditional niceties, leading to further erosion of the activities of many federal agencies," says Vanderbilt's William Schaffner. "But the reality is, if the team is losing, you change the coach. Then agencies really have to buckle down because it will take some time to restore their hard-earned reputations."
[Editor's Note: To read other articles in this special magazine issue, visit the beautifully designed e-reader version.]
Announcing "The Future of Science in America: The Election Issue"
This special magazine explores what's at stake for science & policy over the next four years.
As reviewed in The Washington Post, "Tomorrow's challenges in science and politics: Magazine offers in-depth takes on these U.S. issues":
"Is it time for a new way to help make adults more science-literate? What should the next president know about science? Could science help strengthen American democracy? "The Future of Science in America: The Election Issue" has answers. The free, online magazine is packed with interesting takes on how science can serve the common good. And just in time. This year has challenged leaders, researchers and the public with thorny scientific questions, from the coronavirus pandemic to widespread misinformation on scientific issues. The magazine is a collaboration of the Aspen Institute, a think tank that brings together a variety of public figures and private individuals to tackle thorny social issues, the digital science magazine Leapsmag and GOOD, a social impact company. It's packed with 15 in-depth articles about science with a view toward our campaign year."
The Future of Science in America: The Election Issue offers wide-ranging perspectives on challenges and opportunities for science as we elect our next national and local leaders. The fast-striking COVID-19 pandemic and the more slowly moving pandemic of climate change have brought into sharp focus how reliant we will be on science and public policy to work together to rescue us from crisis. Doing so will require cooperation between both political parties, as well as significant public trust in science as a beacon to light the path forward.
In spite of its unfortunate emergence as a flash point between two warring parties, we believe that science is the driving force for universal progress. No endeavor is more noble than the quest to rigorously understand our world and apply that knowledge to further human flourishing. This magazine aspires to promote roadmaps for science as a tool for health, a vehicle for progress, and a unifier of our nation.
This special issue is a collaboration among LeapsMag, the Aspen Institute Science & Society Program, and GOOD, with support from the Gordon and Betty Moore Foundation and the Rita Allen Foundation.
It is available as a free, beautifully designed digital magazine for both desktop and mobile.
TABLE OF CONTENTS:
- SCIENTISTS:
Award-Winning Scientists Offer Advice to the Next President of the United States - PUBLIC OPINION:
National Survey Reveals Americans' Most Important Scientific Priorities - GOVERNMENT:
The Nation's Science and Health Agencies Face a Credibility Crisis: Can Their Reputations Be Restored? - TELEVISION:
To Make Science Engaging, We Need a Sesame Street for Adults - IMMIGRATION:
Immigrant Scientists—and America's Edge—Face a Moment of Truth This Election - RACIAL JUSTICE:
Democratize the White Coat by Honoring Black, Indigenous, and People of Color in Science - EDUCATION:
I'm a Black, Genderqueer Medical Student: Here's My Hard-Won Wisdom for Students and Educational Institutions - TECHNOLOGY:
"Deep Fake" Video Technology Is Advancing Faster Than Our Policies Can Keep Up - VOTERS:
Mind the (Vote) Gap: Can We Get More STEM Students to the Polls? - EXPERTS:
Who Qualifies as an "Expert" and How Can We Decide Who Is Trustworthy? - SOCIAL MEDIA:
Why Your Brain Falls for Misinformation—And How to Avoid It - YOUTH:
Youth Climate Activists Expand Their Focus and Collaborate to Get Out the Vote - SUPREME COURT:
Abortions Before Fetal Viability Are Legal: Might Science and a Change on the Supreme Court Undermine That? - NAVAJO NATION:
An Environmental Scientist and an Educator Highlight Navajo Efforts to Balance Tradition with Scientific Priorities - CIVIC SCIENCE:
Want to Strengthen American Democracy? The Science of Collaboration Can Help
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.