---
title: "Japan plans Phase IIa trial of TRG035 tooth‑regrowth drug in 24 children"
id: "news-news-dentistry-co-uk-09f88d03a48b3d6cce2d7376"
canonical_url: "https://medichelpline.com/news/news-news-dentistry-co-uk-09f88d03a48b3d6cce2d7376"
content_type: "medical_news_article"
category: "Dentistry"
source_name: "Dentistry.co.uk"
source_url: "https://dentistry.co.uk/2026/08/18/tooth-regrowth-drug-trial-planned-for-24-children-in-japan/"
published_at: "2026-08-18T12:36:57.000Z"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Japan plans Phase IIa trial of TRG035 tooth‑regrowth drug in 24 children
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- **Canonical URL:** https://medichelpline.com/news/news-news-dentistry-co-uk-09f88d03a48b3d6cce2d7376
- **Category:** [Dentistry](https://medichelpline.com/news/dentistry.md)
- **Reporting Source:** Dentistry.co.uk
- **Original Source URL:** [Read Original Article](https://dentistry.co.uk/2026/08/18/tooth-regrowth-drug-trial-planned-for-24-children-in-japan/)
- **Published At:** 2026-08-18T12:36:57.000Z
## Executive Summary & Key Highlights
- Japanese biotech Toregem BioPharma plans a Phase IIa trial of the experimental tooth‑regrowth drug **TRG035** in 24 children with severe **congenital tooth agenesis**. - The Pharmaceuticals and Medical Devices Agency (PMDA) completed its investigation of the clinical trial notification; the study still requires institutional review board (IRB) approval before enrolment can begin. - The planned study is an open‑label, non‑comparative, multicentre trial that will assess dosing in the intended patient population rather than healthy volunteers. - **TRG035** previously completed a Phase I trial at Kyoto University Hospital starting October 2024, enrolling healthy adult men; Toregem reported Phase I confirmed safety but detailed results were not publicly released. - The drug is an antibody designed to block **USAG‑1**, a protein that suppresses tooth development, with the aim of enabling dormant tooth buds to form new teeth; evidence to date comes from animal models and human efficacy has not been shown. - Toregem has said the initial clinical programme focuses on severe congenital tooth agenesis in children, with a longer‑term goal of investigating use for teeth lost to decay and periodontal disease, but timelines and further plans were not reported.
## In-Depth Reporting & Editorial Analysis
## Planned Phase IIa trial will target children with severe congenital tooth agenesis Toregem BioPharma has announced plans for a Phase IIa clinical trial of an experimental tooth‑regrowth medicine, **TRG035**, that would enroll 24 children with severe **congenital tooth agenesis**. The company said Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) completed its investigation of the clinical trial notification for the drug. The study must still pass institutional review board (IRB) assessment before patient enrolment and dosing can begin. Toregem did not disclose a proposed start date for the Phase IIa study in its announcement. ## Study design and purpose: moving from healthy adults into affected children The planned trial is described as an open‑label, non‑comparative, multicentre study focused on dosing in children who have severe congenital tooth agenesis. This will shift testing of **TRG035** from healthy adult volunteers into the population for which the drug is intended. No further details about specific dosing regimens, inclusion criteria beyond severe congenital tooth agenesis, trial sites, or outcome measures were reported. ### Why this trial matters to patients and clinicians Congenital tooth agenesis — the developmental absence of one or more teeth — can cause functional and psychosocial problems for affected children. By targeting this condition directly in a paediatric population, Toregem is seeking evidence that the investigational therapy can stimulate tooth formation where development did not proceed normally. The move into patients is a standard step in clinical development when a therapy has completed initial safety testing in healthy volunteers and the sponsor wishes to evaluate dosing and potential biological activity in the target condition. ## What is TRG035 and how is it intended to work? TRG035 is an antibody treatment designed to block **USAG‑1**, a protein that suppresses tooth development. The intended mechanism is to remove that suppression so that dormant tooth buds can resume development and form new teeth. Toregem has reported positive results in animal models, but **TRG035 has not been shown to regenerate teeth in humans**. Toregem has described the therapeutic goal succinctly: if administration of TRG035 enables tooth formation, patients could be able to eat using their own teeth throughout their lives. The company’s current clinical programme is initially focused on severe congenital tooth agenesis in children, with a longer‑term ambition of investigating whether the treatment could address tooth loss from decay and periodontal disease; the latter remains a distant objective according to the company’s statements. ## Earlier human testing: Phase I study in Kyoto TRG035 previously underwent human testing in a Phase I study conducted at Kyoto University Hospital that began in October 2024. The registered study targeted 30 healthy adult men aged between 30 and 64 who were missing at least one molar. It was a randomised, double‑blind, placebo‑controlled, dose‑escalation study designed primarily to assess safety. Toregem has said that Phase I confirmed the drug’s safety, but detailed results from that trial have not been made publicly available. The company also reported a fundraising round in June to support the next stage of development; Toregem said it raised US$5.3 million, though the announcement did not provide a detailed budget or timeline for the Phase IIa trial. ## Evidence to date and remaining uncertainties Most of the published evidence cited by Toregem relates to positive findings in animal experiments. Human efficacy for tooth regeneration has not been demonstrated. Specific Phase IIa protocol details — including primary and secondary endpoints, age ranges for paediatric participants, follow‑up duration, safety monitoring plans, and criteria for measuring tooth formation — were not reported in the company’s statement covered here. The PMDA’s completion of its investigational review of the clinical trial notification is a regulatory step required in Japan, but local IRB approval is still necessary and the company noted that additional institutional review processes must be completed before the trial can start recruiting. ## What’s next for the programme Next procedural steps reported by Toregem are IRB assessments at participating institutions. Only after those reviews are completed can the company proceed to enrol participants and administer the investigational drug. Toregem has not provided a start date for the Phase IIa study, nor has it released a timeline for anticipated readouts or subsequent trials. Similarly, specifics about the number and location of participating clinical centres were not made public in the announcement. The company’s broader research path, as stated, remains focused initially on children with severe congenital tooth agenesis while keeping open the possibility of future studies targeting adult tooth loss due to decay or periodontal disease. The timing and design of such future studies were not described. ## Context for dental and clinical communities Clinic teams and specialists following regenerative dentistry will likely watch the IRB review process and any future protocol details closely, since this trial represents one of the few moves to test a tooth‑regrowth therapy in paediatric patients. Until detailed Phase IIa protocol information and trial data are published, clinicians should treat efficacy expectations cautiously: animal data and a Phase I safety signal do not yet constitute proof that tooth regrowth is possible in humans. Toregem’s announcement is limited in scope: it confirms regulatory progress at the PMDA and intentions to begin a paediatric study pending IRB approvals, but it leaves many clinical and operational details unreported. Stakeholders seeking more information will need to await further company communications or the public release of the trial protocol and results. ## Reporting note All facts in this report are drawn from Toregem BioPharma’s public announcement and related coverage. Details not included in the source — such as precise trial start dates, protocol endpoints, full Phase I results, and specific site lists — were not reported and therefore are not available here.
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