Scientists Just Started Testing a New Class of Drugs to Slow--and Even Reverse--Aging

Eliminating "zombie-like" cells, called senescent cells, may hold the key to slowing aging and its chronic diseases.

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Imagine reversing the processes of aging. It's an age-old quest, and now a study from the Mayo Clinic may be the first ray of light in the dawn of that new era.

The immune system can handle a certain amount of senescence, but that capacity declines with age.

The small preliminary report, just nine patients, primarily looked at the safety and tolerability of the compounds used. But it also showed that a new class of small molecules called senolytics, which has proven to reverse markers of aging in animal studies, can work in humans.

Aging is a relentless assault of chronic diseases including Alzheimer's, cardiovascular disease, diabetes, and frailty. Developing one chronic condition strongly predicts the rapid onset of another. They pile on top of each other and impede the body's ability to respond to the next challenge.

"Potentially, by targeting fundamental aging processes, it may be possible to delay or prevent or alleviate multiple age-related conditions and many diseases as a group, instead of one at a time," says James Kirkland, the Mayo Clinic physician who led the study and is a top researcher in the growing field of geroscience, the biology of aging.

Getting Rid of "Zombie" Cells

One element common to many of the diseases is senescence, a kind of limbo or zombie-like state where cells no longer divide or perform many regular functions, but they don't die. Senescence is thought to be beneficial in that it inhibits the cancerous proliferation of cells. But in aging, the senescent cells still produce molecules that create inflammation both locally and throughout the body. It is a cycle that feeds upon itself, slowly ratcheting down normal body function and health.

Disease and harmful stimuli like radiation to treat cancer can also generate senescence, which is why young cancer patients seem to experience earlier and more rapid aging. The immune system can handle a certain amount of senescence, but that capacity declines with age. There also appears to be a threshold effect, a tipping point where senescence becomes a dominant factor in aging.

Kirkland's team used an artificial intelligence approach called machine learning to look for cell signaling networks that keep senescent cells from dying. To date, researchers have identified at least eight such signaling networks, some of which seem to be unique to a particular type of cell or tissue, but others are shared or overlap.

Then a computer search identified molecules known to disrupt these signaling pathways "and allow cells that are fully senescent to kill themselves," he explains. The process is a bit like looking for the right weapons in a video game to wipe out lingering zombie cells. But instead of swords, guns, and grenades, the list of biological tools so far includes experimental molecules, approved drugs, and natural supplements.

Treatment

"We found early on that targeting single components of those networks will only kill a very small minority of senescent cells or senescent cell types," says Kirkland. "So instead of going after one drug-one target-one disease, we're going after networks with combinations of drugs or drugs that have multiple targets. And we're going after every age-related disease."

The FDA is grappling with guidance for researchers wanting to conduct clinical trials on something as broad as aging rather than a single disease.

The large number of potential senolytic (i.e. zombie-neutralizing) compounds they identified allowed Kirkland to be choosy, "purposefully selecting drugs where the side effects profile was good...and with short elimination half-lives." The hit and run approach meant they didn't have to worry about maintaining a steady state of drugs in the body for an extended period of time. Some of the compounds they selected need only a half hour exposure to trigger the dying process in senescent cells, which can then take several days.

Work in mice has already shown impressive results in reversing diabetes, weight gain, Alzheimer's, cardiovascular disease and other conditions using senolytic agents.

That led to Kirkland's pilot study in humans with diabetes-related kidney disease using a three-day regimen of dasatinib, a kinase inhibitor first approved in 2006 to treat some forms of blood cancer, and quercetin, a flavonoid found in many plants and sold as a food supplement.

The combination was safe and well tolerated; it reduced the number of senescent cells in the belly fat of patients and restored their normal function, according to results published in September in the journal EBioMedicine. This preliminary paper was based on 9 patients in an ongoing study of 30 patients.

Kirkland cautions that these are initial and incomplete findings looking primarily at safety issues, not effectiveness. There is still much to be learned about the use of senolytics, starting with proof that they actually provide clinical benefit, and against what chronic conditions. The drug combinations, doses, duration, and frequency, not to mention potential risks all must be worked out. Additional studies of other diseases are being developed.

What's Next

Ron Kohanski, a senior administrator at the NIH National Institute on Aging (NIA), says the field of senolytics is so new that there isn't even a consensus on how to identify a senescent cell, and the FDA is grappling with guidance for researchers wanting to conduct clinical trials on something as broad as aging rather than a single disease.

Intellectual property concerns may temper the pharmaceutical industry's interest in developing senolytics to treat chronic diseases of aging. It looks like many mix-and-match combinations are possible, and many of the potential molecules identified so far are found in nature or are drugs whose patents have or will soon expire. So the ability to set high prices for such future drugs, and hence the willingness to spend money on expensive clinical trials, may be limited.

Still, Kohanski believes the field can move forward quickly because it often will include products that are already widely used and have a known safety profile. And approaches like Kirkland's hit and run strategy will minimize potential exposure and risk.

He says the NIA is going to support a number of clinical trials using these new approaches. Pharmaceutical companies may feel that they can develop a unique part of a senolytic combination regimen that will justify their investment. And if they don't, countries with socialized medicine may take the lead in supporting such research with the goal of reducing the costs of treating aging patients.

Bob Roehr
Bob Roehr is a biomedical journalist based in Washington, DC. Over the last twenty-five years he has written extensively for The BMJ, Scientific American, PNAS, Proto, and myriad other publications. He is primarily interested in HIV, infectious disease, immunology, and how growing knowledge of the microbiome is changing our understanding of health and disease. He is working on a book about the ways the body can at least partially control HIV and how that has influenced (or not) the search for a treatment and cure.
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The event on November 12th will explore what lies ahead for science and policy in the near-future.

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EVENT INFORMATION

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Date

Thu Nov 12, 2020 12:00pm - 1:10pm EDT

                            


Contact

kira@goodinc.com

Location

Virtual

Hosts

LeapsMag, the Aspen Institute's Science and Society Program, and GOOD

"The Future of Science in America Summit" will dive into the high stakes ahead as we emerge from a hotly contested election, with the pandemic on the upswing.

Through rotating paired conversations with five experts from academia, industry, advocacy, and government, followed by a public Q&A, this event will explore (re)building public trust in science, the latest science and policy developments on the COVID vaccine front, and moonshots in science that deserve prioritization over the next four years.


________

Nancy Messonnier, M.D.
Director of the National Center for Immunization and Respiratory Diseases (NCIRD)

Saad Amer
Founder, Plus1Vote, a nonprofit organization dedicated to getting out the vote on issues such as climate change and equality

France Córdova, Ph.D.
Astrophysicist, past Director of the National Science Foundation, past President of Purdue University

Joseph DeRisi, Ph.D.
Professor of Biochemistry and Biophysics, University of California San Francisco and Co-President, Chan Zuckerberg Biohub

Seema Kumar
Global Head of the Office of Innovation, Global Health, and Policy Communication, Johnson & Johnson

Michelle McMurry-Heath, M.D., Ph.D.
President and CEO of the Biotechnology Innovation Organization (BIO)

This summit is co-hosted by LeapsMag, the Aspen Institute Science & Society Program, and the social impact company GOOD, with support from the Gordon and Betty Moore Foundation and the Rita Allen Foundation.

The event accompanies our recently published digital magazine, The Future of Science in America: The Election Issue.

Kira Peikoff
Kira Peikoff is a journalist whose 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 son.

Understanding the vulnerabilities of our own brains can help us guard against fake news.

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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.

Whenever you hear something repeated, it feels more true. In other words, repetition makes any statement seem more accurate. So anything you hear again will resonate more each time it's said.

Do you see what I did there? Each of the three sentences above conveyed the same message. Yet each time you read the next sentence, it felt more and more true. Cognitive neuroscientists and behavioral economists like myself call this the "illusory truth effect."

Go back and recall your experience reading the first sentence. It probably felt strange and disconcerting, perhaps with a note of resistance, as in "I don't believe things more if they're repeated!"

Reading the second sentence did not inspire such a strong reaction. Your reaction to the third sentence was tame by comparison.

Why? Because of a phenomenon called "cognitive fluency," meaning how easily we process information. Much of our vulnerability to deception in all areas of life—including to fake news and misinformation—revolves around cognitive fluency in one way or another. And unfortunately, such misinformation can swing major elections.

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Gleb Tsipursky
Dr. Gleb Tsipursky is an internationally recognized thought leader on a mission to protect leaders from dangerous judgment errors known as cognitive biases by developing the most effective decision-making strategies. A best-selling author, he wrote Resilience: Adapt and Plan for the New Abnormal of the COVID-19 Coronavirus Pandemic and Pro Truth: A Practical Plan for Putting Truth Back Into Politics. His expertise comes from over 20 years of consulting, coaching, and speaking and training as the CEO of Disaster Avoidance Experts, and over 15 years in academia as a behavioral economist and cognitive neuroscientist. He co-founded the Pro-Truth Pledge project.