Have you ever imagined walking into a dentist’s office and being told that a missing tooth might one day be replaced by your own body, not a screw in your jaw? That is the promise behind TRG035, a Japanese experimental antibody drug that is moving from an eye-catching lab story into a more serious clinical and business phase.
Official records show the Phase I human study is now listed as complete, and Toregem BioPharma says new funding will support Phase II trials in Japan.
The big takeaway is simple, but it needs a careful note. This is not a drug that patients can ask for yet, and published human data have not shown routine tooth regrowth in people.
Still, for children born without several permanent teeth, and eventually perhaps for adults who lose teeth from decay or gum disease, the work points toward a future where dentistry tries to regenerate instead of only replace.
A drug aimed at tooth buds
TRG035 is a humanized antibody designed to block USAG-1, a protein involved in suppressing tooth development. In practical terms, researchers are trying to remove a biological brake so dormant tooth buds can move forward and form new teeth, at least in patients who still have the right cellular starting point.
Kyoto University says the original Science Advances study found that an antibody targeting USAG-1 stimulated tooth growth in mice with tooth agenesis, and later work showed benefits in ferrets, whose dental patterns are closer to humans.
“We knew that suppressing USAG-1 benefits tooth growth. What we did not know was whether it would be enough,” Katsu Takahashi said in Kyoto University’s research summary. That sentence captures the whole story. The science is promising, but the human test is the hard part.
What the first trial showed
The first-in-human trial was designed mainly to test safety, dosing, and how the body processes the drug. Japan’s clinical trial registry lists the Phase I study as complete, with a target sample of 30 men ages 30 to 64 who were missing at least one molar. Participants received a single intravenous dose of TRG035 or a placebo in a dose-escalation design.
That matters because the first human stage was not built like a final proof-of-effectiveness trial. In everyday terms, it was more like checking whether the road is safe enough before letting more cars onto it.
Toregem later said its AMED Stage Gate milestone included completion of the domestic Phase I clinical trial, a pre-IND meeting with regulators, and progress on its development plan.
Children come first
The first medical target is not cosmetic dentistry or quick fixes for adult tooth loss. Toregem’s orphan-drug materials point to severe congenital hypodontia, a rare condition in which six or more permanent teeth are missing from birth.
For a child, that can affect chewing, speech, appearance, and confidence in ways that show up at school lunch, in photos, and in daily conversations.
Japan’s health ministry granted TRG035 orphan drug status for this target disease in 2025, according to Toregem. That status can bring support such as tax incentives, grant funding, and prioritized review, which helps explain why the company is now pushing toward the next clinical stage.
Kitano Hospital’s clinical plan has also pointed to a future Phase IIa study involving young children with congenital missing teeth.
Why this matters beyond Japan
Tooth loss is not a small niche problem. In the United States, the CDC says about 1 in 10 adults ages 65 to 74 had lost all their teeth in 2017 through March 2020, rising to about 1 in 5 among adults 75 and older. Anyone who has watched a parent struggle with dentures knows this is not just about appearance.
Implants and dentures can work well, but they are still replacements. A living tooth, if researchers can reliably grow one, would be a different kind of solution because it could integrate with the jaw and respond more like natural tissue. That is the dream, anyway.
Business momentum is building
Toregem raised about $5.3 million in Pre-Series C financing, bringing total funding, including grants and subsidies, above $29 million. The company says the money will be used to run Phase II trials of TRG035 in Japan, prepare for future clinical development in the United States, and expand its organization.
That funding is important for a simple reason. A therapy that sounds futuristic still has to survive the ordinary grind of drug development, including manufacturing, monitoring, regulatory meetings, and larger trials. The science may be the spark, but money keeps the lights on.
Caution is still needed
There are several unanswered questions. Will the new teeth grow in the right place? Will they align properly with the bite? Will the effect work only in patients with remaining tooth-bud structures, or could it help people who lost teeth years ago?
There is also the mouth itself, which is not a clean laboratory dish. Gum disease, chronic inflammation, bone loss, and infection could make regeneration harder, especially in older adults with long-term tooth loss. At the end of the day, a drug may open the door, but dentists still have to make sure the room is ready.
What happens next
The 2030 target remains ambitious, but it is no longer just a headline floating around science blogs. Kitano Hospital says the project aims to deliver a tooth-regeneration treatment to patients in 2030, while Toregem’s latest statement says Phase II development is now the next big step.
For now, the most honest way to put it is this: TRG035 has cleared an early human-trial hurdle and is moving deeper into clinical testing, but it still has to prove that it can safely and reliably grow human teeth where patients need them.
The official press release was published on Toregem BioPharma.
