The neuroscientist who interviewed at 19 labs before anyone said yes - then invented the drug they all refused to try.
In 1998, John Ramunas was a 4th-year Electrical Engineering student at the University of Waterloo when he stumbled across a paper about artificial telomere extension. He switched majors to Biochemistry the same week. That pivot - from circuits to chromosomes - set the course for everything that followed.
Today, Ramunas is the Co-Founder and CEO of Rejuvenation Technologies Inc., a Mountain View, California biotechnology company advancing the world's first clinically viable mRNA-based telomere extension therapy. The company's lead drug candidate targets idiopathic pulmonary fibrosis and liver cirrhosis - fatal diseases where telomere shortening is a root cause - with a long-term vision of periodic dosing to maintain healthy telomere length across the entire human lifespan.
The path was not obvious. After completing his PhD in Neuroscience at Stanford's Baxter Laboratory for Stem Cell Biology under Professor Helen Blau, Ramunas spent more than a decade proving that what most of the field assumed was impossible was, in fact, just unstudied. Previous attempts to deliver mRNA encoding TERT (the catalytic component of telomerase) triggered immune responses. Ramunas's approach - using modified, nonimmunogenic mRNA - sidestepped that entirely.
His 2015 paper in The FASEB Journal demonstrated it for the first time: a single transient treatment rapidly extends telomeres in human cells. The biotech world noticed.
A dogma arose in the 1990s that telomerase causes cancer. This is wrong and set back the field by decades.- John Ramunas, PhD - Rejuvenation Technologies Inc.
There is a specific kind of scientific stubbornness that gets confused for naivety right up until it gets confused for genius. Ramunas has had both diagnoses. When he arrived at Stanford's Baxter Laboratory as a PhD student, the field had largely concluded that delivering telomerase into human cells was a dead end - the immune system would simply attack it. Most researchers had moved on. Ramunas had not.
His insight was deceptively simple: the problem was permanence. Previous approaches inserted telomerase genes that kept expressing indefinitely - which is exactly what cancer cells do. What if you could deliver telomerase transiently, as a temporary burst, the way the body naturally does in healthy stem cells? Modified mRNA was the tool. The immune system, it turned out, could be sidestepped.
The 2015 FASEB Journal paper was the proof of concept. One dose of modified TERT mRNA extended telomeres by significant lengths in human cells in culture - lengths that would have taken years to accumulate through natural processes. The paper immediately raised a question: if it works in a dish, what happens in a patient?
Answering that question became Rejuvenation Technologies Inc., co-founded with Blau and Glenn Markov in 2016. Y Combinator picked them up in Summer 2018. By 2023, Khosla Ventures led a $10.6M seed round that also pulled in Shanda Ventures, Asymmetry Ventures, Merchant Adventures, and the Longevity Tech Fund.
The clinical pipeline now targets three indications: RTI-LNG1 for idiopathic pulmonary fibrosis and fibrotic lung disease, RTI-LIV for compensated cirrhosis and alcoholic hepatitis, and RTI-IMM for undisclosed immune conditions. Each was chosen deliberately - fatal orphan diseases where regulatory pathways are faster and the need is undeniable, where proving telomere therapy safe and effective will open the door to everything else.
Here is the detail that most bios skip: Ramunas was Subject #1 in his own company's first human longevity trial. The kind of conviction that requires is not common in drug development. Most CEOs observe. He enrolled.
That willingness to put his body where his data was is consistent with the career arc. He spent his PhD under 19 rejections before Blau said yes. He invented not just the telomere drug but also, in a detour through Stanford's Microfluidics Lab under Professor Juan Santiago, the simplest known miniature peristaltic pump - also patented by Stanford, useful for precise drug delivery. Breadth, in this case, was not distraction. It was infrastructure.
Ramunas describes the near-term strategy with characteristic precision: start with orphan diseases to establish the safety and efficacy track record, then expand. The endgame is not a cure for any single disease. It is periodic maintenance - a single therapy, taken every few years, that keeps telomeres in a healthy length range across the whole human lifespan. Under his model, the question "what disease are you treating?" eventually gives way to "which decade of life are you optimizing?"
That vision is no longer fringe. CIRM awarded the company nearly $4M for the pulmonary fibrosis program. The NIH funded liver work through a STTR grant. The FDA cleared them for INTERACT meetings. Clinical readouts are expected in Q3 2027.
The 19 labs that said no probably don't think about it much. But the 20th - Helen Blau's - helped change the trajectory of longevity science. Sometimes the field is wrong. Sometimes the person in room 20 is right. Ramunas bet his career on exactly that arithmetic.
Every time a human cell divides, its telomeres - the protective caps on chromosome ends - get a little shorter. When they get too short, cells stop dividing, become senescent, or die. This isn't a side effect of aging. According to Ramunas, it is a primary driver of it.
Ramunas's approach delivers modified TERT mRNA - the gene that encodes telomerase's catalytic component - encapsulated in proprietary lipid nanoparticles (LNPs). The cell reads the mRNA, briefly expresses telomerase, extends its telomeres, then degrades the mRNA. No permanent gene insertion. No immune response.
The 2015 FASEB Journal paper demonstrated the concept in human cells: transient TERT mRNA delivery rapidly extends telomeres without triggering an immune response. It has been cited 182+ times and directly underpins the clinical pipeline now targeting fatal lung and liver diseases.
A dominant 1990s theory held that telomerase activation promotes cancer, making it dangerous to deliver therapeutically. Ramunas has challenged this directly: permanent telomerase supports cancer, but transient telomerase - the natural mode in healthy stem cells - does not. The distinction took decades to be taken seriously.
Rejuvenation Technologies uses proprietary lipid nanoparticle technology to deliver TERT mRNA to specific tissues - lung, liver, immune cells. Tissue-specific delivery allows precise therapeutic targeting, limiting systemic exposure while maximizing local telomere extension where it is most needed.
The end state Ramunas describes is not a disease treatment but a maintenance regimen - a single therapy taken every few years to keep telomeres healthy across the entire lifespan. If telomere shortening drives most age-related disease, the logic runs, preventing shortening prevents disease. Systemically.
Our approach may prove useful in delaying, preventing, or treating conditions and diseases of aging as well as certain devastating and lethal genetic diseases.- John Ramunas, PhD - The FASEB Journal, 2015
| Program | Indication | Target Tissue | Stage | Funding Source |
|---|---|---|---|---|
| RTI-LNG1 | Idiopathic Pulmonary Fibrosis / Non-IPF Fibrotic Lung Disease | Lung | Investigator-Initiated Trial | CIRM ($3.98M award) |
| RTI-LIV | Compensated Cirrhosis / Alcoholic Hepatitis | Liver | Investigator-Initiated Trial | NIH STTR R41-AA028749 |
| RTI-IMM | Undisclosed Immune System Conditions | Immune cells | Investigator-Initiated Trial | NIH SBIR Phase II (~$1.08M) |
Short telomeres are fundamental drivers of aging in part because they play a causal role in most other major aging mechanisms including cellular senescence, mitochondrial dysfunction, and loss of stem cell regenerative capacity.
We were surprised and pleased that modified TERT mRNA worked, because TERT is highly regulated and must bind to another component of telomerase. Previous attempts to deliver mRNA-encoding TERT caused an immune response against telomerase. In contrast, our technique is nonimmunogenic.
Most of these are downstream of short telomeres, but our approach addresses the fundamental aging clock.
Since each dose reverses years of telomere shortening, the treatments could be years apart.
IP protection is important as a startup company in drug development because it enables raising the necessary early-stage funding.
Safety is our primary concern for use in patients, and much work remains to be done to test and improve safety.