Dr. Michael West has a storied legacy in the world of aging research. Twenty years ago, the company he started, Geron, hit upon a major breakthrough when his scientists isolated the active component for the gene that confers immortality to cells, called telomerase.
In the twenty years since, a new field has emerged: the science of extending the human "healthspan."
He was in the lab when scientists for the first time artificially turned on the gene in some skin cells donated by Dr. Leonard Hayflick, the man who had discovered back in 1965 that human cells age over time. Sure enough, with Geron's intervention, Hayflick's skin cells became immortal in the dish, and the landmark paper was published in Science in 1998.
In the twenty years since, a new field has emerged: the science of extending the human "healthspan" – the length of time people can live free of diseases related to aging. A substantial amount of preclinical and some clinical research is now underway, backed by heavy investments from some of the world's largest companies.
Today, Dr. West is the CEO of AgeX Therapeutics, a biotech company that is developing novel therapeutics to target human aging and age-related degenerative diseases using pluripotent stem cells. Dr. West recently shared some key insights with Editor-in-Chief Kira Peikoff about what's happening in this exciting space.
1) Pluripotent stem cells have opened the door for the first time in human history to manufacturing young cells and young tissue of any kind.
These are the body's master cells: They are self-replicating, and they can potentially give rise to any cell or tissue the body needs to repair itself. This year marks the 20th anniversary since their isolation for the first time in a lab.
"People in biotech say that the time from lab to discovery in products is about 20 years," West says. "But the good news is we're at that 20-year mark now, so you're seeing an explosive growth of applications. We can now make all cell types of the human body in a scalable manner."
2) Early human development could hold the key to unlocking the mystery of aging.
West believes that two things occur when the body forms in utero: telomerase, the immortalizing gene, gets turned off very early in development in the body cells like skin, liver, and nerves. Additionally, he thinks that a second genetic switch gets turned off that holds the potential for regeneration after injury.
"These insights open the door to intervention by the transfer of telomerase into the cells of the body."
"Very early when the body is first forming, if you cut the skin, it will not respond by scarring, but will regenerate scarlessly," he says. "But that potential gets turned off once the body is formed, about 8 weeks after fertilization. Then, you accumulate damage over a lifetime. Not only do cells have a finite capacity to replicate, but you have tissue damage."
However, there are animals in nature whose telomerase is never turned off, or whose regenerative ability is never turned off. The flatworm, for example, can regenerate its own head if it gets cut off, and it also shows no detectable aging. Lobsters are believed to be similar. (That's not to say it can't get caught and eaten for dinner.)
"These insights open the door to intervention by the transfer of telomerase into the cells of the body, or understanding how regeneration gets turned off, and then turning it back on," West says. "That's well within the power of modern medical research to understand."
3) Companies are investing tremendous resources into the anti-aging gold rush.
Devising interventions is the mission of AgeX, a subsidiary of BioTime, as well as a number of other companies.
"We're seeing a mad rush," West says. There's Google's Calico, which recently announced, with AbbVie Inc., another $1 billion into research for age-related diseases, on top of the previous $1.5 billion investment.
Other notable players include Unity Biotechnology, Samumed, Human Longevity Inc., RestorBio, Rejuvenate Bio,and Juvenescence (which is also an investor in AgeX).
"These are products in development by our company and others that the baby boomers can reasonably anticipate being available within their lifetimes."
4) The majority of clinical applications are still years away.
"What we've learned about turning back on this regenerative state, called induced tissue regeneration, is that the majority of the clinical implications are years away and will require years of clinical trials before potential FDA approval and marketing to the public," West says. "But we have found some potential near-term applications that we think may have a much faster track to commercialization. As you can imagine, we are all over those."
BioTime, Inc., AgeX's parent, has a regenerative medicine product in clinical trials for age-related macular degeneration, the leading cause of blindness in an aging population. While not yet approved by the FDA, BioTime has reported continued progress in the clinical development of the product now in Phase II trials.
Dr. Michael West, CEO of AgeX
Citi recently issued a major report, Disruptive Innovations VI, that included "Anti-Aging Medicines" as the number two innovation for investors to keep an eye on, and predicted that the first anti-aging therapies could receive regulatory approval by 2023.
5) Few, if any, medical interventions are available today that are proven to markedly slow aging - yet. But the Baby Boomers are not necessarily out of luck.
Buyer beware of any claims in the marketplace that a given skin cream or stem cell product will extend your life. More than likely, they won't.
"There are a lot of people trying to cash in on the aging baby boom population," West warns.
"When you hear claims of stem cell products that you can get now, it's important to understand that they are likely not based on pluripotent stem cell technology. Also, they are usually not products approved by the FDA, having gone through clinical trials to demonstrate safety and efficacy."
However, an array of young pluripotent stem cell-derived therapies are on a development track for future approvals.
One example is another program at AgeX: the manufacture of brown fat cells; these cells burn calories rather than store them. They burn circulating fat like triglycerides and sugar in the blood and generate heat.
"You lose brown fat in aging, and animal models suggest that if you restore that tissue, you can restore a metabolic balance to be more like what you had when you were young," says West. "When I was 18, I could drink milkshakes all day long and not gain an ounce. But at 50 or 60, most of us would rapidly put on weight. Why? We believe that one important factor is that with age, you lose this brown fat tissue. The loss throws your metabolism off balance. So the solution is conceptually simple, we plan to make young brown fat cells for transplantation to reset the balance, potentially to treat Type II diabetes or even obesity.
"These are products in development by our company and others that the baby boomers can reasonably anticipate being available within their lifetimes."
6) There is an ethical debate about how far to apply this new science.
Some people are speculating about whether genetic engineering might one day be used to program longer lifespans into humans at the earliest stages of development. (Note: it is against the law across the Western world to edit human embryos intended for reproduction, although just last week, Chinese scientists used CRISPR to repair a disease-causing mutation in viable human embryos.)
West sounds a cautionary note about such interventions meant to lengthen life. "For people who think not just about the science, but the ethics, safety is a major concern. It's entirely possible to genetically engineer babies, but when you make such modifications, it's an experiment, not just in human cells in a dish, but in a human being. I have a great reticence to put any human at risk unless it's a case where the person is suffering with a life-threatening disease, and the potential therapy is their last best hope."
"I have no doubt, zero doubt, that in the foreseeable future, we'll hear of a person who has lived to about 150."
7) The biggest challenge of intervening in human aging is cultural denial.
"The prospect of intervening in a profound way in human aging is still not seen as credible by the vast majority of thoughtful people around the world," West laments.
"Aging is a universal phenomenon, it's mankind's greatest enemy, but as a species we've adapted to the realities of finite lifespans and death. We have a whole infrastructure of belief systems around this, and many people see it as inevitable."
8) The lifespan for healthy children born today could surpass anything humanity has ever seen.
"It is at least 150 years of age," West predicts. "I have no doubt, zero doubt, that in the foreseeable future, we'll hear of a person who has lived to about 150. We know now it's possible. I've never said that publicly before, but I am comfortable now with the prediction. And, of course, if some people now living could live to 150 years of age, we have the prospect of them living to see even more powerful therapies. So, the question now is, what kind of a world are we going to make for future generations?"
[Editor's Note: Check out our latest video, which was inspired by Dr. West's exclusive prediction to leapsmag.]
In November 2020, messenger RNA catapulted into the public consciousness when the first COVID-19 vaccines were authorized for emergency use. Around the same time, an equally groundbreaking yet relatively unheralded application of mRNA technology was taking place at a London hospital.
Over the past two decades, there's been increasing interest in harnessing mRNA — molecules present in all of our cells that act like digital tape recorders, copying instructions from DNA in the cell nucleus and carrying them to the protein-making structures — to create a whole new class of therapeutics.
Scientists realized that artificial mRNA, designed in the lab, could be used to instruct our cells to produce certain antibodies, turning our bodies into vaccine-making factories, or to recognize and attack tumors. More recently, researchers recognized that mRNA could also be used to make another groundbreaking technology far more accessible to more patients: gene editing. The gene-editing tool CRISPR has generated plenty of hype for its potential to cure inherited diseases. But delivering CRISPR to the body is complicated and costly.
"Most gene editing involves taking cells out of the patient, treating them and then giving them back, which is an extremely expensive process," explains Drew Weissman, professor of medicine at the University of Pennsylvania, who was involved in developing the mRNA technology behind the COVID-19 vaccines.
But last November, a Massachusetts-based biotech company called Intellia Therapeutics showed it was possible to use mRNA to make the CRISPR system inside the body, eliminating the need to extract cells out of the body and edit them in a lab. Just as mRNA can instruct our cells to produce antibodies against a viral infection, it can also teach them to produce the two molecular components that make up CRISPR — a guide molecule and a cutting protein — to snip out a problem gene.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies."
In Intellia's London-based clinical trial, the company applied this for the first time in a patient with a rare inherited liver disease known as hereditary transthyretin amyloidosis with polyneuropathy. The disease causes a toxic protein to build up in a person's organs and is typically fatal. In a company press release, Intellia's president and CEO John Leonard swiftly declared that its mRNA-based CRISPR therapy could usher in a "new era of potential genome editing cures."
Weissman predicts that turning CRISPR into an affordable therapy will become the next major frontier for mRNA over the coming decade. His lab is currently working on an mRNA-based CRISPR treatment for sickle cell disease. More than 300,000 babies are born with sickle cell every year, mainly in lower income nations.
"There is a FDA-approved cure, but it involves taking the bone marrow out of the person, and then giving it back which is prohibitively expensive," he says. It also requires a patient to have a matched bone marrow done. "We give an intravenous injection of mRNA lipid nanoparticles that target CRISPR to the bone marrow stem cells in the patient, which is easy, and much less expensive."
Meanwhile, the overwhelming success of the COVID-19 vaccines has focused attention on other ways of using mRNA to bolster the immune system against threats ranging from other infectious diseases to cancer.
The practicality of mRNA vaccines – relatively small quantities are required to induce an antibody response – coupled with their adaptable design, mean companies like Moderna are now targeting pathogens like Zika, chikungunya and cytomegalovirus, or CMV, which previously considered commercially unviable for vaccine developers. This is because outbreaks have been relatively sporadic, and these viruses mainly affect people in low-income nations who can't afford to pay premium prices for a vaccine. But mRNA technology means that jabs could be produced on a flexible basis, when required, at relatively low cost.
Other scientists suggest that mRNA could even provide a means of developing a universal influenza vaccine, a goal that's long been the Holy Grail for vaccinologists around the world.
"The mRNA technology allows you to pick out bits of the virus that you want to induce immunity to," says Michael Mulqueen, vice president of business development at eTheRNA, a Belgium-based biotech that's developing mRNA-based vaccines for malaria and HIV, as well as various forms of cancer. "This means you can get the immune system primed to the bits of the virus that don't vary so much between strains. So you could actually have a single vaccine that protects against a whole raft of different variants of the same virus, offering more universal coverage."
Before mRNA became synonymous with vaccines, its biggest potential was for cancer treatments. BioNTech, the German biotech company that collaborated with Pfizer to develop the first authorized COVID-19 vaccine, was initially founded to utilize mRNA for personalized cancer treatments, and the company remains interested in cancers ranging from melanoma to breast cancer.
One of the major hurdles in treating cancer has been the fact that tumors can look very different from one person to the next. It's why conventional approaches, such as chemotherapy or radiation, don't work for every patient. But weaponizing mRNA against cancer primes the immune cells with the tumor's specific genetic sequence, training the patient's body to attack their own unique type of cancer.
"It means you're able to think about personalizing cancer treatments down to specific subgroups of patients," says Mulqueen. "For example, eTheRNA are developing a renal cell carcinoma treatment which will be targeted at around 20% of these patients, who have specific tumor types. We're hoping to take that to human trials next year, but the challenge is trying to identify the right patients for the treatment at an early stage."
Repairing Damaged mRNA
While hopes are high that mRNA could usher in new cancer treatments and make CRISPR more accessible, a growing number of companies are also exploring an alternative to gene editing, known as RNA editing.
In genetic disorders, the mRNA in certain cells is impaired due to a rogue gene defect, and so the body ceases to produce a particular vital protein. Instead of permanently deleting the problem gene with CRISPR, the idea behind RNA editing is to inject small pieces of synthetic mRNA to repair the existing mRNA. Scientists think this approach will allow normal protein production to resume.
Over the past few years, this approach has gathered momentum, as some researchers have recognized that it holds certain key advantages over CRISPR. Companies from Belgium to Japan are now looking at RNA editing to treat all kinds of disorders, from Huntingdon's disease, to amyotrophic lateral sclerosis, or ALS, and certain types of cancer.
"With RNA editing, you don't need to make any changes to the DNA," explains Daniel de Boer, CEO of Dutch biotech ProQR, which is looking to treat rare genetic disorders that cause blindness. "Changes to the DNA are permanent, so if something goes wrong, that may not be desirable. With RNA editing, it's a temporary change, so we dose patients with our drugs once or twice a year."
Last month, ProQR reported a landmark case study, in which a patient with a rare form of blindness called Leber congenital amaurosis, which affects the retina at the back of the eye, recovered vision after three months of treatment.
"We have seen that this RNA therapy restores vision in people that were completely blind for a year or so," says de Boer. "They were able to see again, to read again. We think there are a large number of other genetic diseases we could go after with this technology. There are thousands of different mutations that can lead to blindness, and we think this technology can target approximately 25% of them."
Ultimately, there's likely to be a role for both RNA editing and CRISPR, depending on the disease. "I think CRISPR is ideally suited for illnesses where you would like to permanently correct a genetic defect," says Joshua Rosenthal of the Marine Biology Laboratory in Chicago. "Whereas RNA editing could be used to treat things like pain, where you might want to reset a neural circuit temporarily over a shorter period of time."
Much of this research has been accelerated by the COVID-19 pandemic, which has played a major role in bringing mRNA to the forefront of people's minds as a therapeutic.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies," says Mulqueen. "In the future, I would not be surprised if many of the top pharma products are mRNA derived."
"Making Sense of Science" is a monthly podcast that features interviews with leading medical and scientific experts about the latest developments and the big ethical and societal questions they raise. This episode is hosted by science and biotech journalist Emily Mullin, summer editor of the award-winning science outlet Leaps.org.