Metformin Tested in Children With Recurrent PFA Ependymoma — Phase 2 Trial Recruiting at Six US Centers
NCT07226453 (UCSF, six US centers) is recruiting patients aged 1–39 with recurrent or progressive PFA ependymoma to test whether metformin changes the tumor's epigenetic markers (EZHIP/H3K27me3) and stabilizes disease. No results yet.
By Sanare Lab · October 15, 2026 · 2 min read
Key Takeaway
A US trial is recruiting children and young adults (ages 1–39) with recurrent PFA ependymoma — an aggressive brain tumor — to test whether the common diabetes drug metformin can switch the tumor's epigenetic settings back toward normal. No results yet; this is a trial announcement.
PFA ependymoma is a childhood brain tumor driven not by DNA mutations but by epigenetics — chemical settings that control which genes are active. Its cells carry too much EZHIP (a protein that blocks a normal "off switch" on gene packaging) and too little H3K27me3 (that off switch itself — a chemical tag on histones, the spools DNA wraps around).
The phase 2 trial (phase 2 = mid-stage testing of whether a treatment shows an effect) uses a clever window design: participants take metformin for about six weeks before their planned tumor surgery. Doctors then compare the removed tumor with the pre-treatment biopsy. The primary endpoint — the main question the trial must answer — is whether enough patients show a 10% drop in EZHIP and/or a 10% rise in H3K27me3. A second phase measures the disease stabilization rate by RAPNO criteria (standard rules for judging brain-tumor scans in children).
The study is non-randomized and open-label (everyone gets metformin; no placebo group), aims for 30 participants, and runs at six US centers including UCSF and Johns Hopkins; completion is expected around 2030. Context: pooled metformin trials in adults have been sobering — see our review of 19 pooled metformin trials — and for other repurposing attempts in children's brain tumors, see another repurposing approach in pediatric brain tumors. Dosing questions: our dosing calculator.
In plain words
What happened: Doctors at six US hospitals are testing the diabetes pill metformin in children and young adults whose PFA ependymoma — a brain tumor — came back after surgery and radiation.
Why it matters: This tumor grows because its gene switches are set wrong, not because of DNA damage. Metformin might flip some switches back; patients take it before surgery so doctors can check the removed tumor for changes.
How strong is the evidence: A registered phase 2 trial, now recruiting — there are no results yet. It is small (30 planned) with no placebo group — it can show hints, not proof.
What it means for you: If your child has recurrent PFA ependymoma, ask your oncology team about trial NCT07226453. Do not start metformin on your own — it has real risks.
References
- Target Validation and Efficacy of Metformin in Patients With Posterior Fossa Group A (PFA) Ependymoma (phase 2, recruiting; trial record — no results yet). ClinicalTrials.gov. Record updated 2026 Oct 14. ClinicalTrials.gov: NCT07226453.
Medical Disclaimer
This article is informational, not medical advice. A trial registration describes a plan, not proven results. Never change medication without consulting your doctor.
Sanare Lab
Science-based health education team reviewing published research on repurposed drugs, integrative oncology, and evidence-based protocols.