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.
Podcast: The future of brain health with Percy Griffin
Today's guest is Percy Griffin, director of scientific engagement for the Alzheimer’s Association, a nonprofit that’s focused on speeding up research, finding better ways to detect Alzheimer’s earlier and other approaches for reducing risk. Percy has a doctorate in molecular cell biology from Washington University, he’s led important research on Alzheimer’s, and you can find the link to his full bio in the show notes, below.
Our topic for this conversation is the present and future of the fight against dementia. Billions of dollars have been spent by the National Institutes of Health and biotechs to research new treatments for Alzheimer's and other forms of dementia, but so far there's been little to show for it. Last year, Aduhelm became the first drug to be approved by the FDA for Alzheimer’s in 20 years, but it's received a raft of bad publicity, with red flags about its effectiveness, side effects and cost.
Meanwhile, 6.5 million Americans have Alzheimer's, and this number could increase to 13 million in 2050. Listen to this conversation if you’re concerned about your own brain health, that of family members getting older, or if you’re just concerned about the future of this country with experts predicting the number people over 65 will increase dramatically in the very near future.
Listen to the Episode
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4:40 - We talk about the parts of Percy’s life that led to him to concentrate on working in this important area.
6:20 - He defines Alzheimer's and dementia, and discusses the key elements of communicating science.
10:20 - Percy explains why the Alzheimer’s Association has been supportive of Aduhelm, even as others have been critical.
17:58 - We talk about therapeutics under development, which ones to be excited about, and how they could be tailored to a person's own biology.
24:25 - Percy discusses funding and tradeoffs between investing more money into Alzheimer’s research compared to other intractable diseases like cancer, and new opportunities to accelerate progress, such as ARPA-H, President Biden’s proposed agency to speed up health breakthroughs.
27:24 - We talk about the social determinants of brain health. What are the pros/cons of continuing to spend massive sums of money to develop new drugs like Aduhelm versus refocusing on expanding policies to address social determinants - like better education, nutritious food and safe drinking water - that have enabled some groups more than others to enjoy improved cognition late in life.
34:18 - Percy describes his top lifestyle recommendations for protecting your mind.
37:33 - Is napping bad for the brain?
39:39 - Circadian rhythm and Alzheimer's.
42:34 - What tests can people take to check their brain health today, and which biomarkers are we making progress on?
47:25 - Percy highlights important programs run by the Alzheimer’s Association to support advances.
Show links:
** After this episode was recorded, the Centers for Medicare and Medicaid Services affirmed its decision from last June to limit coverage of Aduhelm. More here.
- Percy Griffin's bio: https://www.alz.org/manh/events/alztalks/upcoming-...
- The Alzheimer's Association's Part the Cloud program: https://alz.org/partthecloud/about-us.asp
- The paradox of dementia rates decreasing: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455342/
- The argument for focusing more resources on improving institutions and social processes for brain health: https://www.statnews.com/2021/09/23/the-brain-heal...
- Recent research on napping: https://www.ocregister.com/2022/03/25/alzheimers-s...
- The Alzheimer's Association helpline: https://www.alz.org/help-support/resources/helpline
- ALZConnected, a free online community for people affected by dementia https://www.alzconnected.org/
- TrialMatch for people with dementia and healthy volunteers to find clinical trials for Alzheimer's and other dementia: https://www.alz.org/alzheimers-dementia/research_p...
COVID-19 prompted numerous companies to reconsider their approach to the future of work. Many leaders felt reluctant about maintaining hybrid and remote work options after vaccines became widely available. Yet the emergence of dangerous COVID variants such as Omicron has shown the folly of this mindset.
To mitigate the risks of new variants and other public health threats, as well as to satisfy the desires of a large majority of employees who express a strong desire in multiple surveys for a flexible hybrid or fully remote schedule, leaders are increasingly accepting that hybrid and remote options represent the future of work. No wonder that a February 2022 survey by the Federal Reserve Bank of Richmond showed that more and more firms are offering hybrid and fully-remote work options. The firms expect to have more remote workers next year and more geographically-distributed workers.
Although hybrid and remote work mitigates public health risks, it poses another set of health concerns relevant to employee wellbeing, due to the threat of proximity bias. This term refers to the negative impact on work culture from the prospect of inequality among office-centric, hybrid, and fully remote employees.
The difference in time spent in the office leads to concerns ranging from decreased career mobility for those who spend less facetime with their supervisor to resentment building up against the staff who have the most flexibility in where to work. In fact, a January 2022 survey by the company Slack of over 10,000 knowledge workers and their leaders shows that proximity bias is the top concern – expressed by 41% of executives - about hybrid and remote work.
To address this problem requires using best practices based on cognitive science for creating a culture of “Excellence From Anywhere.” This solution is based on guidance that I developed for leaders at 17 pioneering organizations for a company culture fit for the future of work.
Protect from proximity bias via the "Excellence From Anywhere" strategy
So why haven’t firms addressed the obvious problem of proximity bias? Any reasonable external observer could predict the issues arising from differences of time spent in the office.
Unfortunately, leaders often fail to see the clear threat in front of their nose. You might have heard of black swans: low-probability, high-impact threats. Well, the opposite kind of threats are called gray rhinos: obvious dangers that we fail to see because of our mental blindspots. The scientific name for these blindspots is cognitive biases, which cause leaders to resist best practices in transitioning to a hybrid-first model.
The core idea is to get all of your workforce to pull together to achieve business outcomes: the location doesn’t matter.
Leaders can address this by focusing on a shared culture of “Excellence From Anywhere.” This term refers to a flexible organizational culture that takes into account the nature of an employee's work and promotes evaluating employees based on task completion, allowing remote work whenever possible.
Addressing Resentments Due to Proximity Bias
The “Excellence From Anywhere” strategy addresses concerns about treatment of remote workers by focusing on deliverables, regardless of where you work. Doing so also involves adopting best practices for hybrid and remote collaboration and innovation.
By valuing deliverables, collaboration, and innovation through a focus on a shared work culture of “Excellence From Anywhere,” you can instill in your employees a focus on deliverables. The core idea is to get all of your workforce to pull together to achieve business outcomes: the location doesn’t matter.
This work culture addresses concerns about fairness by reframing the conversation to focus on accomplishing shared goals, rather than the method of doing so. After all, no one wants their colleagues to have to commute out of spite.
This technique appeals to the tribal aspect of our brains. We are evolutionarily adapted to living in small tribal groups of 50-150 people. Spending different amounts of time in the office splits apart the work tribe into different tribes. However, cultivating a shared focus on business outcomes helps mitigate such divisions and create a greater sense of unity, alleviating frustrations and resentments. Doing so helps improve employee emotional wellbeing and facilitates good collaboration.
Solving the facetime concerns of proximity bias
But what about facetime with the boss? To address this problem necessitates shifting from the traditional, high-stakes, large-scale quarterly or even annual performance evaluations to much more frequent weekly or biweekly, low-stakes, brief performance evaluation through one-on-one in-person or videoconference check-ins.
Supervisees agree with their supervisor on three to five weekly or biweekly performance goals. Then, 72 hours before their check-in meeting, they send a brief report, under a page, to their boss of how they did on these goals, what challenges they faced and how they overcame them, a quantitative self-evaluation, and proposed goals for next week. Twenty-four hours before the meeting, the supervisor responds in a paragraph-long response with their initial impressions of the report.
It’s hard to tell how much any employee should worry about not being able to chat by the watercooler with their boss: knowing exactly where they stand is the key concern for employees, and they can take proactive action if they see their standing suffer.
At the one-on-one, the supervisor reinforces positive aspects of performance and coaches the supervisee on how to solve challenges better, agrees or revises the goals for next time, and affirms or revises the performance evaluation. That performance evaluation gets fed into a constant performance and promotion review system, which can replace or complement a more thorough annual evaluation.
This type of brief and frequent performance evaluation meeting ensures that the employee’s work is integrated with efforts by the supervisor’s other employees, thereby ensuring more unity in achieving business outcomes. It also mitigates concerns about facetime, since all get at least some personalized attention from their team leader. But more importantly, it addresses the underlying concerns about career mobility by giving all staff a clear indication of where they stand at all times. After all, it’s hard to tell how much any employee should worry about not being able to chat by the watercooler with their boss: knowing exactly where they stand is the key concern for employees, and they can take proactive action if they see their standing suffer.
Such best practices help integrate employees into a work culture fit for the future of work while fostering good relationships with managers. Research shows supervisor-supervisee relationships are the most critical ones for employee wellbeing, engagement, and retention.
Conclusion
You don’t have to be the CEO to implement these techniques. Lower-level leaders of small rank-and-file teams can implement these shifts within their own teams, adapting their culture and performance evaluations. And if you are a staff member rather than a leader, send this article to your supervisor and other employees at your company: start a conversation about the benefits of addressing proximity bias using such research-based best practices.