The First Cloned Monkeys Provoked More Shrugs Than Shocks
Zhong Zhong and Hua Hua, the two cloned macaques.
A few months ago, it was announced that not one, but two healthy long-tailed macaque monkeys were cloned—a first for primates of any kind. The cells were sourced from aborted monkey fetuses and the DNA transferred into eggs whose nuclei had been removed, the same method that was used in 1996 to clone "Dolly the Sheep." Two live births, females named Zhong Zhong and Hua Hua, resulted from 60 surrogate mothers. Inefficient, it's true. But over time, the methods are likely to be improved.
The scientist who supervised the project predicts that cloning, along with gene editing, will result in "ideal primate models" for studying disease mechanisms and drug screening.
Dr. Gerald Schatten, a famous would-be monkey cloner, authored a controversial paper in 2003 describing the formidable challenges to cloning monkeys and humans, speculating that the feat might never be accomplished. Now, some 15 years later, that prediction, insofar as it relates to monkeys, has blown away.
Zhong Zhong and Hua Hua were created at the Chinese Academy of Science's Institute of Neuroscience in Shanghai. The Institute founded in 1999 boasts 32 laboratories, expanding to 50 labs in 2020. It maintains two non-human primate research facilities.
The founder and director, Dr. Mu-ming Poo, supervised the project. Poo is an extremely accomplished senior researcher at the pinnacle of his field, a distinguished professor emeritus in Biology at UC Berkeley. In 2016, he was awarded the prestigious $500,000 Gruber Neuroscience Prize. At that time, Poo's experiments were described by a colleague as being "innovative and very often ingenious."
Poo maintains the reputation of studying some of the most important questions in cellular neuroscience.
But is society ready to accept cloned primates for medical research without the attendant hysteria about fears of cloned humans?
By Western standards, use of non-human primates in research focuses on the welfare of the animal subjects. As PETA reminds us, there is a dreadful and sad history of mistreatment. Dr. Poo assures us that his cloned monkeys are treated ethically and that the Institute is compliant with the highest regulatory standards, as promulgated by the U.S. National Institutes of Health.
He presents the noblest justifications for the research. He predicts that cloning, along with gene editing, will result in "ideal primate models" for studying disease mechanisms and drug screening. He declares that this will eventually help to solve Parkinson's, Huntington's and Alzheimer's disease.
But is society ready to accept cloned primates for medical research without the attendant hysteria about fears of cloned humans? It appears so.
While much of the news coverage expressed this predictable worry, my overall impression is that the societal response was muted. Where was the expected outrage? Then again, we've come a long way since Dolly the Sheep in terms of both the science and the cultural acceptance of cloning. Perhaps my unique vantage point can provide perspective on how much attitudes have evolved.
Perhaps my unique vantage point can provide perspective on how much attitudes have evolved.
I sometimes joke that I am the world's only human cloning lawyer—a great gig but there are still no clients.
I first crashed into the cloning scene in 2002 when I sued the so-called human cloning company "Clonaid" and asked in court to have a temporary guardian appointed for the alleged first human clone "Baby Eve." The claim needed to be tested, and mine was the first case ever aiming to protect the rights of a human clone. My legal basis was child welfare law, protecting minors from abuse, negligence, and exploitation.
The case had me on back-to-back global television broadcasts around the world; there was live news and "breathless" coverage at the courthouse emblazoned in headlines in every language on the planet. Cloning was, after all, perceived as a species-altering event: asexual reproduction. The controversy dominated world headlines for month until Clonaid's claim was busted as the "fakest" of fake news.
Fresh off the cloning case, the scientific community reached out to me, seeing me as the defender of legitimate science, an opponent of cloning human babies but a proponent of using cloning techniques to accelerate ethical regenerative medicine and embryonic stem cell research in general.
The years 2003 to 2006 were the era of the "stem cell wars" and a dominant issue was human cloning. Social conservative lawmakers around the world were seeking bans or criminalization not only of cloning babies but also the cloning of cells to match the donor's genetics. Scientists were being threatened with fines and imprisonment. Human cloning was being challenged in the United Nations with the United States backing a global treaty to ban and morally condemn all cloning -- including the technique that was crucial for research.
Scientists and patients were touting the cloning technique as a major biomedical breakthrough because cells could be created as direct genetic matches from a specific donor.
At the same time, scientists and patients were touting the cloning technique as a major biomedical breakthrough because cells could be created as direct genetic matches from a specific donor.
So my organization organized a conference at UN headquarters to defend research cloning and all the big names in stem cell research were there. We organized petitions to the UN and faxed 35,000 signatures to the country mission. These ongoing public policy battles were exacerbated in part because of the growing fear that cloning babies was just around the corner.
Then in 2005, the first cloned dog stunned the world, an Afghan hound named Snuppy. I met him when I visited the laboratories of Professor Woo Suk Hwang in Korea. His minders let me hold his leash -- TIME magazine's scientific breakthrough of the year. He didn't lick me or even wag his tail; I figured he must not like lawyers.
Tragically, soon thereafter, I witnessed firsthand Dr. Hwang's fall from grace when his human stem cell cloning breakthroughs proved false. The massive scientific misconduct rocked the nation of Korea, stem cell science in general, and provoked terrible news coverage.
Nevertheless, by 2007, the proposed bans lost steam, overridden by the advent of a Japanese researcher's Nobel Prize winning formula for reprogramming human cells to create genetically matched cell lines, not requiring the destruction of human embryos.
After years of panic, none of the recent cloning headlines has caused much of a stir.
Five years later, when two American scientists accomplished therapeutic human cloned stem cell lines, their news was accepted without hysteria. Perhaps enough time had passed since Hwang and the drama was drained.
In the just past 30 days we have seen more cloning headlines. Another cultural icon, Barbara Streisand, revealed she owns two cloned Coton de Tulear puppies. The other weekend, the television news show "60 Minutes" devoted close to an hour on the cloned ponies used at the top level of professional polo. And in India, scientists just cloned the first Assamese buffalo.
And you know what? After years of panic, none of this has caused much of a stir. It's as if the future described by Alvin Toffler in "Future Shock" has arrived and we are just living with it. A couple of cloned monkeys barely move the needle.
Perhaps it is the advent of the Internet and the overall dilution of wonder and outrage. Or maybe the muted response is rooted in popular culture. From Orphan Black to the plotlines of dozens of shows and books, cloning is just old news. The hand-wringing discussions about "human dignity" and "slippery slopes" have taken a backseat to the AI apocalypse and Martian missions.
We humans are enduring plagues of dementia and Alzheimer's, and we will need more monkeys. I will take mine cloned, if it will speed progress.
Personally, I still believe that cloned children should not be an option. Child welfare laws might be the best deterrent.
The same does not hold for cloning monkey research subjects. Squeamishness aside, I think Zhong Zhong and Hua Hua will soon be joined by a legion of cloned macaques and probably marmosets.
We humans are enduring plagues of dementia and Alzheimer's, and we will need more monkeys. I will take mine cloned, if it will speed the mending of these consciousness-destroying afflictions.
Scientific revolutions once took centuries, then decades, and now seem to bombard us daily. The convergence of technologies has accelerated the future. To Zhong Zhong and Hua Hua, my best wishes with the hope that their sacrifices will contribute to the health of all primates -- not just humans.
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.
Podcast: The Friday Five weekly roundup in health research
This week's Friday Five covers promising research on a potential saliva test for post-traumatic stress disorder, cancer detection with a microchip, resilient food for climate change, the best posture for pill taking, and more.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five:
- Using graphene to repair shoulders
- Testing for PTSD with saliva
- Cancer detection with a microchip
- Best posture for pill taking
- Resilient food for climate change
And an honorable mention goes to research on a new way to induce healthy fat.