SPECIAL Informat.ro / Eternal youth, by resetting the biological clock: how science wants to reverse aging

A genetic therapy authorized for the first time by the U.S. Food and Drug Administration (FDA) in 2026 launches one of the boldest theories in modern biology: that aging can not only be slowed down but reversed at the cellular level.

What is aging, really?

For decades, the dominant theory in the biology of aging has maintained that cells age primarily due to the accumulation of mutations in DNA — errors in the genetic code that accumulate over a lifetime and disrupt the normal functioning of genes. However, a series of studies in recent years has disproven this view as a unique explanation.

Professor David Sinclair's lab at Harvard Medical School has demonstrated that an equally important — if not primary — cause of aging is the deterioration of epigenetic information: it is not the genetic code itself that breaks down, but the way it is read and regulated by cells.

What does epigenetics mean, in simple terms?

The DNA of every cell in an individual is identical, whether we are talking about a nerve cell, muscle cell, or liver cell. What differentiates these cells is epigenetics — a system of "chemical markers" and protein structures (histones, methyl groups) that function like a switch: some genes are activated, others blocked, depending on the type and function of the cell. Sinclair describes epigenetics as the "operating system of the cell" — not the source code (DNA), but the instructions that tell the cell how to use it.

As we age, these markers become disorganized. Cells "forget" what type of cells they are, tissues lose functionality, and organs fail. This is the core of what Sinclair calls the Informational Theory of Aging — formulated back in the 1990s and experimentally demonstrated on mice in 2023, in a study published in the journal Cell.

The experiment that changed the paradigm

Sinclair's team created an experimental system called ICE (Inducible Changes to the Epigenome — induced epigenetic changes). In short: researchers induced temporary and rapid cuts in the DNA of laboratory mice, mimicking the type of micro-injuries that cells suffer daily due to respiration, exposure to radiation, or chemicals. These breaks did not affect the gene sequence — thus did not produce mutations — but altered the way DNA is packaged and organized.

What was observed: the epigenetic proteins responsible for regulating genes became "distracted" — they moved to the break sites to coordinate repairs and did not return to their initial positions. The epigenome gradually became disorganized. Mice began to show signs of accelerated aging: cells lost their identity, organs functioned poorly.

The conclusion of the study was that epigenetic degradation can, in itself, be a driver of aging, independent of genetic mutations.

"Rebooting" cells: the OSK cocktail

The next step — and the most spectacular — was reversing the process. Researchers administered to mice a gene therapy based on three genes known by the acronym OSK (OCT4, SOX2, and KLF4), normally active in stem cells, with the ability to "retrograde" mature cells to a younger state.

These genes are part of the set of four Yamanaka factors, discovered by Japanese scientist Shinya Yamanaka, who won the Nobel Prize in 2012 for demonstrating that adult cells can be reprogrammed to the state of stem cells. The essential distinction brought by Sinclair's team: the OSK cocktail omits the fourth factor (c-Myc, which promotes cancer) and halts reprogramming before the cells become stem cells — which would be dangerous in the body. The process is described as a partial epigenetic reprogramming.

Results in mice were remarkable: organs and tissues returned to a younger state. Cells restored the epigenetic markers from youth without losing their identity. Sinclair metaphorically named the process: "rebooting a malfunctioning computer." An early application, published in 2020 on the cover of the journal Nature, showed that OSK therapy restored vision in mice with optic nerve damage.

From the lab to the first human test: ER-100

On January 28, 2026, the biotechnology company Life Biosciences — co-founded by Sinclair — announced that it had received FDA authorization for the first human clinical study of a cellular rejuvenation therapy based on partial epigenetic reprogramming.

The therapy is called ER-100 and works as follows: a viral vector (a virus modified to be non-pathogenic) delivers the OSK genes directly into retinal ganglion cells — the cells that transmit light signals from the eyes to the brain. A second vector, activated by the antibiotic doxycycline, functions as a safety switch: patients start the therapy by taking a doxycycline pill and stop it by discontinuing administration.

The Phase I study tests the therapy in two eye conditions — glaucoma and non-arteritic anterior ischemic optic neuropathy (NAION) — since the FDA does not yet recognize aging as a standalone disease. The primary objective is safety, but researchers will also monitor indicators of efficacy: visual acuity, OCT scans, immune response. Studies on non-human primates with NAION have already shown that ER-100 restored epigenetic information and improved the electrical signaling of the optic nerve.

Initial safety data are expected by the end of 2026.

Who else is working in this field?

Life Biosciences got a head start over other well-funded companies working on the same technological platform: Altos Labs, backed by Jeff Bezos with $3 billion, is working on its own version of partial epigenetic reprogramming; Retro Biosciences, funded by Sam Altman (OpenAI), and New Limit, supported by Brian Armstrong (CEO of Coinbase), are also exploring cellular reprogramming therapies.

Prospects for success and limitations

The theory has a solid scientific foundation, built over more than three decades of research. The publication of the ICE study in Cell (2023) represented the first demonstration that epigenetic changes can cause aging in mammals — not just in humans. Studies on non-human primates have shown promising results, and the FDA has accepted the therapy for human testing — a signal that the platform has a credible preclinical basis.

However, skepticism in the scientific community remains consistent. Not all researchers agree that partial reprogramming constitutes a true reversal of biological age. Additionally, Sinclair has promoted substances (resveratrol, NMN supplements) that have not fully confirmed their efficacy in humans, which fuels reservations about his predictions.

There are also real technical risks: delivering gene therapy on a large scale via viral vectors raises questions about immune response, long-term gene expression control, and potential unintended effects. The ER-100 therapy cannot regenerate already dead cells — it can only restore damaged but functional ones.

When could it become widely functional?

Realistically, the road is long. The Phase I study, with up to 12-18 patients, focuses exclusively on safety. Phase II would test efficacy on a larger number of patients, and Phase III — on thousands of participants, compared to a standard treatment. The complete journey of a drug from Phase I to approval takes, on average, 10-15 years.

Even if the results in 2026 are positive, a systemic application — to rejuvenate not just an organ but the entire body — is at least two decades away from mass clinical use, in the most optimistic scenario. There are also regulatory barriers: the FDA currently does not recognize aging as a therapeutic indication, which forces companies to anchor therapies in specific diseases.

The long-term vision of the Life Biosciences team is, however, explicit: "a phased approach, organ by organ, indication by indication," but with the ultimate goal of multi-organ rejuvenation.

Conclusion

The partial epigenetic reprogramming method based on the OSK cocktail likely represents the most advanced and well-documented therapeutic candidate in the field of longevity at this time. The first human test authorized in 2026 is a turning point: if the ER-100 therapy demonstrates that it can restore visual function in human patients by resetting the cellular epigenome, validating the underlying principle of the Informational Theory of Aging will open a new era in medicine — one in which the treatment of age-related diseases could address the causes that triggered them, not just the symptoms.

For now, science is in the waiting room for the first clinical response. And that response could be, after all calculations, the most important in the history of modern medicine.

Material created with the help of Perplexity