A single injection. One day it may replace dentures, implants and bridges.
That is what a Japanese team hopes to prove in the first-ever human trial of a drug designed to regrow lost teeth. Toregem Biopharma, a startup from Osaka, began the study in October 2024 at Kitano Hospital in Osaka. The first phase tests safety and dosage in healthy adult men who have lost at least one molar. If the drug passes that stage, the next phase will target a much narrower group: children aged two to seven who were born without the ability to grow some of their permanent teeth.
The company has already set a target date for widespread use. Toregem Biopharma wants the drug available for routine clinical use by 2030.
That timeline is ambitious. It is also based on a discovery that goes back several years. In 2021, Katsu Takahashi and colleagues published their preclinical results in Science Advances. The team showed that an antibody drug could block a protein called USAG-1 in mice and ferrets. USAG-1 normally suppresses tooth development. Switch it off, and a dormant tooth bud can wake up and grow.
The study did not just produce new mini-teeth. Blocking USAG-1 allowed the newly formed teeth to connect with the jawbone and the surrounding nerve tissue. In the mouse model, one injection was enough. The treated animals developed teeth that looked and functioned like natural ones.
In ferrets, which are closer to humans in tooth size and development, the drug produced the same result. The team then moved to safety studies and scaled up production. That led to the human trial and the current push toward a licensed product.
The drug itself is an antibody called TRG-035. Antibodies are normally known as tools the immune system uses to fight infections. Here, the idea is different. TRG-035 binds to USAG-1 and prevents it from doing its usual job of damping down tooth growth signals. When that brake is released, pathways that are already involved in dental development, such as BMP and Wnt signaling, can do more work.
The company reports that the drug was designed to act locally and break down quickly in the body, which should reduce the chance of tooth growth in the wrong place. That is the kind of safety question regulators will look at carefully.
If approved, the drug will not be useful only for older adults with missing teeth. The first real medical need the trial addresses is congenital tooth loss. A very small number of people are born with all their teeth missing, a condition called complete congenital anodontia. A larger group is missing just a few teeth for the same reason. For these patients, current options are mostly mechanical: implants, bridges or removable dentures. None of them restores the natural biology of a living tooth embedded in bone. A drug that grows a real tooth would change that.
The broader question everyone asks is whether this could eventually become a routine alternative to dental work. The number of missing adult teeth worldwide is huge, and the global dental implant market alone was valued at around five billion US dollars in 2023. A regeneration pill or single injection could redraw that market, even if it starts with only a few specific cases.
That said, there is still a long road ahead. Phase I in humans will not show whether people can regrow full molars. It will show whether the drug is safe, how it behaves in the body and whether the planned dose makes biological sense. Phase II will test early signs of effectiveness in children. Only if those stages pass could the trial move toward the kind of data a regulator would need for a formal approval.
Even then, the goal is not to regrow thousands of teeth at once. The company says that even restoring one or two missing teeth in people with severe defects would still be a major step.
Still, the science itself is worth watching. Mammals do not regenerate body parts the way some fish and salamanders do. Yet teeth are unusual even in mammals. They develop late in embryogenesis, go through a repeated bud-cap-shape process and require tight coordination of many signaling molecules. For a long time, they were thought to be a one-way process: form once and then stop. This study suggests otherwise.
If the trial is successful, it could become one of the first examples of targeted pharmaceutical regeneration in humans. Not a prosthetic, and not a transplant. A drug telling the body to rebuild a structure that was lost or never formed.
For now, the trial has a clear next step: safety in a small group of adult patients. If that goes well, the focus will shift to children who may benefit the most.
Dentistry has not changed in its core approach for a long time. Drill, fill, extract, replace. If this drug moves through the pipeline as planned, that pattern could finally start to bend.
References
Takahashi, K., Nambu, N., Hata, K., Takahashi, M., Mizuma, T., Sakai, E., Imai, Y., Nishiyama, T., Saito-Ohno, A., Yamada-Sasaki, N., Uehara, M., Kato, K., Uesugi-Tanaka, Y., Ogawa, S., & Hosoya, A. (2021). Anti-USAG-1 therapy for tooth regeneration through enhanced BMP signaling. Science Advances, 7(7), eabf1798. https://doi.org/10.1126/sciadv.abf1798
Toregem Biopharma. (2024). TRG-035 antibody drug. Toregem Biopharma. https://toregem.co.jp/en/
IFLScience. (2024, June 22). Medicine for regrowing teeth to be tested on humans for the first time. https://www.iflscience.com/medicine-for-regrowing-teeth-to-be-tested-on-humans-for-the-first-time-74777
