A Drug That Could Grow New Teeth Moves Into Its Next Phase of Human Testing

For most of dental history, a lost tooth has been a permanent loss. Implants and dentures can fill the gap, but no treatment has been able to coax the jaw into producing a real, living tooth. That may be inching closer to changing. A Kyoto University spinout called Toregem BioPharma is advancing a drug called TRG035 toward Phase II clinical trials, the stage where a treatment is tested in patients who actually have the condition it aims to treat.

The drug works by blocking a protein called USAG-1, which normally suppresses tooth development, with the goal of activating dormant tooth buds and stimulating new tooth growth.

The approach rests on the idea that humans retain vestigial tooth buds capable of producing a third set of teeth, but that USAG-1 ordinarily prevents these from ever developing.

For now, the company is focused on a narrow and serious condition:

severe congenital hypodontia, defined as the absence of six or more permanent teeth from birth.

Children with this condition can spend a decade or more in dentures that must be remade as their jaws grow, before eventually transitioning to implant surgery in adulthood.

A Phase I safety study, run from late 2024 through 2025 in adult men missing at least one molar, wrapped up its data collection without any serious adverse events reported.

In July 2026, Toregem also announced it had been selected for two Kyoto overseas expansion support programs, which the company said would help it build international research partnerships and licensing activity around TRG035.

Experts urge caution about timelines.

TRG035 still needs Phase II efficacy data and further regulatory review before it could become available, and the next stage of development is focused on severe congenital hypodontia — not tooth loss caused by gum disease, trauma, or decay.

Some researchers have also raised questions about whether the approach can work as effectively in adults, who have far fewer of the dental epithelial cells that play a foundational role in tooth development.

The science is genuinely novel, but a treatment available at a dental office remains years away — and, for now, would apply to a specific rare condition rather than the everyday tooth loss most adults experience.