Japanese Biotech Firm Secures Funding for Phase II Trials of Tooth Regrowth Drug

Modern dentistry relies entirely on artificial replacements—titanium implants, porcelain crowns, and acrylic dentures. Once an adult tooth is lost, the human body cannot replace it. But a pioneering clinical trial currently underway in Japan is attempting to rewrite that fundamental biological rule.[1][2]

Kyoto University spin-off Toregem BioPharma has developed an experimental monoclonal antibody, known as TRG035, designed to stimulate the body to grow a natural "third set" of teeth.[2][3]

In mid-2026, the company announced it had raised approximately $5.3 million in a Pre-Series C financing round to advance the drug into Phase II clinical trials. This milestone follows a Phase I safety trial, launched in late 2024, which tested the drug on 30 healthy adult men missing at least one molar.[1][3]

The mechanism behind TRG035 sounds like science fiction, but it relies on dormant biological pathways that already exist. Humans naturally grow two sets of teeth: baby teeth and adult teeth. However, researchers discovered that humans also possess tiny, residual "tooth buds" embedded in the jaw that theoretically have the potential to form a third set.[2][5]

These dormant buds are kept permanently inactive by a specific protein called USAG-1, which acts as a molecular off-switch for tooth development. By neutralizing this protein, TRG035 removes the biological barrier, signaling the dormant buds to wake up and begin growing into fully functional teeth.[1][4]

The foundational research, led by Dr. Katsu Takahashi, began nearly two decades ago. Initial animal trials demonstrated that a single injection of the antibody successfully promoted the growth of "third generation" teeth in mice and ferrets without notable side effects.[1][2]

While the ultimate dream is to replace teeth lost to decay or injury in adults, the immediate clinical focus is on a rare genetic condition. The upcoming Phase II trials will target children aged 2 to 7 who suffer from congenital tooth agenesis.[2][3]

Congenital agenesis, or hypodontia, affects roughly one in a thousand people, causing them to be born missing six or more teeth. The condition leads to severe chewing difficulties, nutritional challenges, and significant social stigma, often requiring young children to wear dentures or face masks.[2][5]

For these children, a successful regenerative therapy would be life-changing. It would eliminate the need for a lifetime of invasive dental prosthetics that must be constantly resized and surgically adjusted as their jaws grow.[3][5]

If the pediatric trials prove successful, Toregem BioPharma aims to make the treatment commercially available by 2030. Eventually, the company hopes to expand the drug's application to the broader adult population.[2][4]

The implications for aging societies are profound. In Japan alone, government data indicates that over 90% of adults over the age of 75 are missing at least one tooth. Restoring natural dentition could drastically improve systemic health, nutrition, and overall quality of life for seniors worldwide.[2][5]

Despite the optimism and recent funding, independent dental experts caution that significant hurdles remain. While the Phase I safety data appears favorable, actual tooth regeneration in humans has not yet been officially confirmed in peer-reviewed literature.[3][4]

Dr. Mary MacDougall, dean of the faculty of dentistry at the University of British Columbia, has pointed out that the therapy relies heavily on the presence of dental epithelial cells. While children with congenital conditions still possess these foundational cells, older adults who lost teeth decades ago may lack the necessary cellular architecture to grow a new tooth.[4][6]

Another major clinical challenge is targeting. Researchers must ensure that the systemic antibody only triggers tooth growth in the specific empty socket, rather than causing unwanted extra teeth to erupt randomly across the jaw.[4][6]

A recent study on cellular self-organization offered some hope on this front, showing that tooth growth cells taken from different parts of the mouth naturally reorganize themselves to form the correct tissue structures when stimulated.[1]

For now, TRG035 remains strictly investigational. Dentists emphasize that while biological tooth regeneration is closer to reality than ever before, patients should continue prioritizing traditional oral hygiene and preventive care, as commercial availability for the general public is still years away.[2][5]