The Cocktail Report (sound really smart around your friends):
TRG-035, a monoclonal antibody (a lab-engineered protein that targets a specific molecule in the body) developed by Toregem BioPharma, is currently in Phase 1 human trials at Kyoto University Hospital in Japan, making it the first tooth-regeneration drug ever tested in humans.
The drug works by blocking USAG-1 (uterine sensitization-associated gene-1), a protein that acts as a biological brake preventing dormant third-set tooth buds from developing. Humans are born with these buds already in the jaw; USAG-1 keeps them suppressed throughout life.
Phase 1 enrolled 30 healthy adult males aged 30 to 64, each missing at least one tooth. The trial ran from September 2024 through approximately August 2025 and focused on safety and proper dosing.
In animal studies, a single intravenous dose of the antibody caused mice and ferrets to grow complete, fully functional new teeth that naturally integrated into the jawbone with no adverse effects.
TRG-035 has received orphan drug designation from Japan's Ministry of Health, accelerating its regulatory pathway.
If Phase 1 results are clean, the next phase will test the drug in children aged 2 to 7 with congenital anodontia (a condition where some or all permanent teeth fail to develop from birth), the population with the greatest medical need and clearest regulatory pathway.
The team's stated goal is commercial availability by 2030, initially for congenital tooth absence and eventually for adult tooth loss from injury, decay, or disease.
This matters beyond dentistry: the biology being unlocked here, reactivating dormant developmental programs from birth to regenerate tissue, is the same principle researchers are pursuing in cartilage, nerve, and organ regeneration.
In Article 025 of this newsletter, we covered the Longevity Bottleneck Hypothesis, which proposes that mammals lost tooth regeneration genes during the dinosaur era. TRG-035 is, in a real sense, a scientific attempt to recover one of those losses.
If you have ever lost a tooth to decay, injury, or time, you already know that your two biological chances are it. Adult teeth do not grow back, unlike bones, which heal themselves.
That may be about to change.
Lead researcher Katsu Takahashi of Kitano Hospital in Osaka has spent nearly three decades studying USAG-1 (uterine sensitization-associated gene-1, a protein that acts as a permanent biological off-switch for tooth development), and his core discovery is counterintuitive. Humans already have dormant third-set tooth buds sitting in their jaws from birth, and USAG-1 simply keeps them switched off for life.
TRG-035, the antibody drug developed at Toregem BioPharma, turns that switch off. In mice and ferrets, a single intravenous dose caused complete, fully integrated new teeth to grow from dormant buds with no adverse effects.
The animals grew real biological teeth from tissue that had been waiting since birth, not implants or transplants.
Phase 1 human trials began in September 2024 at Kyoto University Hospital, enrolling 30 adult men aged 30 to 64, each missing at least one tooth. The yearlong trial focused on safety and dosing, and no serious adverse events have been reported.
TRG-035 has received orphan drug designation from Japan's Ministry of Health, accelerating regulatory review.
If the Phase 1 results hold, the next stage targets children aged 2 to 7 with congenital anodontia (a condition where permanent teeth fail to develop from birth), a population that currently has no biological treatment option. After that, the broader goal is adult tooth loss from any cause, including decay, periodontal disease, and injury.
The commercial target is 2030, assuming clean Phase 2 results and successful regulatory submissions in Japan. That timeline is optimistic, and real hurdles remain.
But a confirmed Phase 1 safety foundation changes the odds substantially.
This research matters beyond dentistry. The underlying principle, reactivating a dormant developmental program with a single antibody, is the same framework being pursued in cartilage repair, optic nerve regeneration, and organ rejuvenation.
TRG-035 is one of the clearest demonstrations yet that the body's regenerative capacity is larger than we currently use.
Why Should You Care?
Dental implants cost $3,000 to $5,000 per tooth, require surgery, and don't replicate the biological function of a real tooth. For the roughly 178 million Americans missing at least one tooth, TRG-035 represents a genuinely different category of solution.
Beyond the practical, this is a proof of concept for the broader idea that biological regeneration, not replacement or repair, is the future of medicine. Watching tooth trials succeed would accelerate every other regenerative program that follows.
Citations:
Kitano Hospital / Toregem BioPharma. "Investigator-led clinical trials begin for tooth regeneration treatment drug." May 3, 2024. https://www.kitano-hp.or.jp/english/info/20240503/
Popular Mechanics / Darren Orf. "Humans May Be Able to Grow New Teeth Within Just 4 Years." May 1, 2026. https://www.popularmechanics.com/science/health/a71184991/human-new-tooth-regrowth-trials-timeline/
Concierge Dental Group. "Japanese Scientists Begin Human Trials for Tooth Regrowth Drug." 2025. https://conciergedentalgroup.com/blog/tooth-regrowth-drug/
JStories. "World's first 'teething drug' clinical trial starts in September." June 7, 2024. https://jstories.media/the-worlds-first-drug-that-helps-patients-grow-new-teeth-update/
