The Nobel Prize-Winning Treatment Approach That Could Tackle COVID-19
In October 2006, Craig Mello received a strange phone call from Sweden at 4:30 a.m. The voice at the other end of the line told him to get dressed and that his life was about to change.
"We think this could be effective in [the early] phase, helping the body clear the virus and preventing progression to that severe hyperimmune response which occurs in some patients."
Shortly afterwards, he was informed that along with his colleague Andrew Fire, he had won the Nobel Prize in Physiology or Medicine.
Eight years earlier, biologists Fire and Mello had made a landmark discovery in the history of genetics. In a series of experiments conducted in worms, they had revealed an ancient evolutionary mechanism present in all animals that allows RNA – the structures within our cells that take genetic information from DNA and use it to make proteins – to selectively switch off genes.
At the time, scientists heralded the dawn of a new field of medical research utilizing this mechanism, known as RNA interference or RNAi, to tackle rare genetic diseases and deactivate viruses. Now, 14 years later, the pharmaceutical company Alnylam — which has pioneered the development of RNAi-based treatments over the past decade — is looking to use it to develop a groundbreaking drug for the virus that causes COVID-19.
"We can design small interfering RNAs to target regions of the viral genome and bind to them," said Akin Akinc, who manages several of Alnylam's drug development programs. "What we're learning about COVID-19 is that there's an early phase where there's lots of viral replication and a high viral load. We think this could be effective in that phase, helping the body clear the virus and preventing progression to that severe hyperimmune response which occurs in some patients."
Called ALN-COV, Alnylam's treatment hypothetically works by switching off a key gene in the virus, inhibiting its ability to replicate itself. In order to deliver it to the epithelial cells deep in the lung tissue, where the virus resides, patients will inhale a fine mist containing the RNAi molecules mixed in a saline solution, using a nebulizer.
But before human trials of the drug can begin, the company needs to convince regulators that it is both safe and effective in a series of preclinical trials. While early results appear promising - when mixed with the virus in a test tube, the drug displayed a 95 percent inhibition rate – experts are reserving judgment until it performs in clinical trials.
"If successful this could be a very important milestone in the development of RNAi therapies, but virus infections are very complicated and it can be hard to predict whether a given level of inhibition in cell culture will be sufficient to have a significant impact on the course of the infection," said Si-Ping Han, who researches RNAi therapeutics at California Institute of Technology and is not involved in the development of this drug.
So far, Alnylam has had success in using RNAi to treat rare genetic diseases. It currently has treatments licensed for Hereditary ATTR Amyloidosis and Acute Hepatic Porphyria. Another treatment, for Primary Hyperoxaluria Type 1, is currently under regulatory review. But its only previous attempt to use RNAi to tackle a respiratory infection was a failed effort to develop a drug for respiratory syncytial virus (RSV) almost a decade ago.
However, the technology has advanced considerably since then. "Back then, RNAi drugs had no chemical modifications whatsoever, so they were readily degraded by the body, and they could also result in unintended immune stimulation," said Akinc. "Since then, we've learned how to chemically modify our RNAi's to make them immunosilent and give them improved potency, stability, and duration of action."
"It would be a very important milestone in the development of RNAi therapies."
But one key challenge the company will face is the sheer speed at which viruses evolve, meaning they can become drug-resistant very quickly. Scientists predict that Alnylam will ultimately have to develop a series of RNAi drugs for the coronavirus that work together.
"There's been considerable interest in using RNAi to treat viral infections, as RNA therapies can be developed more rapidly than protein therapies like monoclonal antibodies, since one only needs to know the viral genome sequence to begin to design them," said David Schaffer, professor of bioengineering at University of California, Berkeley. "But viruses can evolve their sequences rapidly around single drugs so it is likely that a combinatorial RNAi therapy may be needed."
In the meantime, Alnylam is conducting further preclinical trials over the summer and fall, with the aim of launching testing in human volunteers by the end of this year -- an ambitious aim that would represent a breakneck pace for a drug development program.
If the approach does ultimately succeed, it would represent a major breakthrough for the field as a whole, potentially opening the door to a whole new wave of RNAi treatments for different lung infections and diseases.
"It would be a very important milestone in the development of RNAi therapies," said Han, the Caltech researcher. "It would be both the first time that an RNAi drug has been successfully used to treat a respiratory infection and as far as I know, the first time that one has been successful in treating any disease in the lungs. RNAi is a platform that can be reconfigured to hit different targets, and so once the first drug has been developed, we can expect a rapid flow of variants targeting other respiratory infections or other lung diseases."
Stronger psychedelics that rewire the brain, with Doug Drysdale
A promising development in science in recent years has been the use technology to optimize something natural. One-upping nature's wisdom isn't easy. In many cases, we haven't - and maybe we can't - figure it out. But today's episode features a fascinating example: using tech to optimize psychedelic mushrooms.
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These mushrooms have been used for religious, spiritual and medicinal purposes for thousands of years, but only in the past several decades have scientists brought psychedelics into the lab to enhance them and maximize their therapeutic value.
Today’s podcast guest, Doug Drysdale, is doing important work to lead this effort. Drysdale is the CEO of a company called Cybin that has figured out how to make psilocybin more potent, so it can be administered in smaller doses without side effects.
The natural form of psilocybin has been studied increasingly in the realm of mental health. Taking doses of these mushrooms appears to help people with anxiety and depression by spurring the development of connections in the brain, an example of neuroplasticity. The process basically shifts the adult brain from being fairly rigid like dried clay into a malleable substance like warm wax - the state of change that's constantly underway in the developing brains of children.
Neuroplasticity in adults seems to unlock some of our default ways of of thinking, the habitual thought patterns that’ve been associated with various mental health problems. Some promising research suggests that psilocybin causes a reset of sorts. It makes way for new, healthier thought patterns.
So what is Drysdale’s secret weapon to bring even more therapeutic value to psilocybin? It’s a process called deuteration. It focuses on the hydrogen atoms in psilocybin. These atoms are very light and don’t stick very well to carbon, which is another atom in psilocybin. As a result, our bodies can easily breaks down the bonds between the hydrogen and carbon atoms. For many people, that means psilocybin gets cleared from the body too quickly, before it can have a therapeutic benefit.
In deuteration, scientists do something simple but ingenious: they replace the hydrogen atoms with a molecule called deuterium. It’s twice as heavy as hydrogen and forms tighter bonds with the carbon. Because these pairs are so rock-steady, they slow down the rate at which psilocybin is metabolized, so it has more sustained effects on our brains.
Cybin isn’t Drysdale’s first go around at this - far from it. He has over 30 years of experience in the healthcare sector. During this time he’s raised around $4 billion of both public and private capital, and has been named Ernst and Young Entrepreneur of the Year. Before Cybin, he was the founding CEO of a pharmaceutical company called Alvogen, leading it from inception to around $500 million in revenues, across 35 countries. Drysdale has also been the head of mergers and acquisitions at Actavis Group, leading 15 corporate acquisitions across three continents.
In this episode, Drysdale walks us through the promising research of his current company, Cybin, and the different therapies he’s developing for anxiety and depression based not just on psilocybin but another psychedelic compound found in plants called DMT. He explains how they seem to have such powerful effects on the brain, as well as the potential for psychedelics to eventually support other use cases, including helping us strive toward higher levels of well-being. He goes on to discuss his views on mindfulness and lifestyle factors - such as optimal nutrition - that could help bring out hte best in psychedelics.
Show links:
Doug Drysdale full bio
Doug Drysdale twitter
Cybin website
Cybin development pipeline
Cybin's promising phase 2 research on depression
Johns Hopkins psychedelics research and psilocybin research
Mets owner Steve Cohen invests in psychedelic therapies
Doug Drysdale, CEO of Cybin
How the body's immune resilience affects our health and lifespan
Story by Big Think
It is a mystery why humans manifest vast differences in lifespan, health, and susceptibility to infectious diseases. However, a team of international scientists has revealed that the capacity to resist or recover from infections and inflammation (a trait they call “immune resilience”) is one of the major contributors to these differences.
Immune resilience involves controlling inflammation and preserving or rapidly restoring immune activity at any age, explained Weijing He, a study co-author. He and his colleagues discovered that people with the highest level of immune resilience were more likely to live longer, resist infection and recurrence of skin cancer, and survive COVID and sepsis.
Measuring immune resilience
The researchers measured immune resilience in two ways. The first is based on the relative quantities of two types of immune cells, CD4+ T cells and CD8+ T cells. CD4+ T cells coordinate the immune system’s response to pathogens and are often used to measure immune health (with higher levels typically suggesting a stronger immune system). However, in 2021, the researchers found that a low level of CD8+ T cells (which are responsible for killing damaged or infected cells) is also an important indicator of immune health. In fact, patients with high levels of CD4+ T cells and low levels of CD8+ T cells during SARS-CoV-2 and HIV infection were the least likely to develop severe COVID and AIDS.
Individuals with optimal levels of immune resilience were more likely to live longer.
In the same 2021 study, the researchers identified a second measure of immune resilience that involves two gene expression signatures correlated with an infected person’s risk of death. One of the signatures was linked to a higher risk of death; it includes genes related to inflammation — an essential process for jumpstarting the immune system but one that can cause considerable damage if left unbridled. The other signature was linked to a greater chance of survival; it includes genes related to keeping inflammation in check. These genes help the immune system mount a balanced immune response during infection and taper down the response after the threat is gone. The researchers found that participants who expressed the optimal combination of genes lived longer.
Immune resilience and longevity
The researchers assessed levels of immune resilience in nearly 50,000 participants of different ages and with various types of challenges to their immune systems, including acute infections, chronic diseases, and cancers. Their evaluation demonstrated that individuals with optimal levels of immune resilience were more likely to live longer, resist HIV and influenza infections, resist recurrence of skin cancer after kidney transplant, survive COVID infection, and survive sepsis.
However, a person’s immune resilience fluctuates all the time. Study participants who had optimal immune resilience before common symptomatic viral infections like a cold or the flu experienced a shift in their gene expression to poor immune resilience within 48 hours of symptom onset. As these people recovered from their infection, many gradually returned to the more favorable gene expression levels they had before. However, nearly 30% who once had optimal immune resilience did not fully regain that survival-associated profile by the end of the cold and flu season, even though they had recovered from their illness.
Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance.
This could suggest that the recovery phase varies among people and diseases. For example, young female sex workers who had many clients and did not use condoms — and thus were repeatedly exposed to sexually transmitted pathogens — had very low immune resilience. However, most of the sex workers who began reducing their exposure to sexually transmitted pathogens by using condoms and decreasing their number of sex partners experienced an improvement in immune resilience over the next 10 years.
Immune resilience and aging
The researchers found that the proportion of people with optimal immune resilience tended to be highest among the young and lowest among the elderly. The researchers suggest that, as people age, they are exposed to increasingly more health conditions (acute infections, chronic diseases, cancers, etc.) which challenge their immune systems to undergo a “respond-and-recover” cycle. During the response phase, CD8+ T cells and inflammatory gene expression increase, and during the recovery phase, they go back down.
However, over a lifetime of repeated challenges, the immune system is slower to recover, altering a person’s immune resilience. Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance despite the many respond-and-recover cycles that their immune systems have faced.
Public health ramifications could be significant. Immune cell and gene expression profile assessments are relatively simple to conduct, and being able to determine a person’s immune resilience can help identify whether someone is at greater risk for developing diseases, how they will respond to treatment, and whether, as well as to what extent, they will recover.