The technology, developed by PolTREG, focuses on engineering regulatory T cells so they can identify specific disease processes and migrate to affected organs such as the pancreas, brain, joints or intestines, depending on the condition being treated. Researchers say the approach could eventually be applied across dozens of autoimmune diseases.

Regulatory T cells are a subset of immune cells that suppress excessive immune responses and help prevent the immune system from attacking the body’s own tissues. Their dysfunction is associated with conditions including type 1 diabetes, multiple sclerosis and Hashimoto’s disease.

The second-generation therapy builds on earlier work conducted at the Medical University of Gdańsk, where regulatory T cells were first used in human treatment in 2007 in patients with graft-versus-host disease following bone marrow transplantation.

PolTREG emerged as a scientific spin-off from that research and has since been developing cell therapies based on TREG lymphocytes.

Professor Piotr Trzonkowski, an immunologist and transplant specialist who co-founded PolTREG and leads research in the field, told PAP: “The first generation of our therapy involves collecting TREG cells from the patient, multiplying them in a specialized laboratory and re-administering them to the patient.

“Over the course of two decades, we have conducted five clinical trials on this solution. The entire research was conducted in Poland and financed with domestic capital. Today, this method is in the market authorization process at the European Medicines Agency (EMA)”

He added that the first-generation therapy is already used in limited form under hospital exemption rules at the University Clinical Centre in Gdańsk. In January 2026, the EMA accepted PolTREG-T1D (PTG-007) for submission under the central marketing authorization procedure.

The limitation of the first-generation approach is that infused regulatory T cells circulate broadly in the body rather than concentrating at disease sites.

The new therapy aims to solve this by giving TREG cells antigen specificity, effectively equipping them with a biological “navigation system” that guides them to inflamed or damaged tissue.

“This invention focuses on a method of teaching cells not to wander randomly, but to go to a precisely defined place, i.e. where the disease develops,” Trzonkowski said.

Researchers say this could improve both effectiveness and safety by increasing concentration at the disease site while reducing off-target activity.

The Medical University of Gdańsk holds the patent rights, while PolTREG holds an exclusive license.

The therapy remains in the preclinical stage and will require clinical trials, with development estimated to take five to six years.

The research team is also conducting early preventive trials in children at high risk of type 1 diabetes, aiming to intervene before clinical symptoms appear.

In parallel, scientists are working on an experimental mRNA-based approach that would instruct the body to produce regulatory T cells internally, potentially reducing costs significantly.

“In this model, cells are not administered to the patient. Instead, the patient is injected with a biological instruction written in mRNA, thanks to which the body itself begins to produce appropriate TREG cells,” Trzonkowski said, adding that such therapy “may be several dozen or even several hundred times cheaper.”

Trzonkowski is head of the Department of Clinical Immunology and Transplantology at the Medical University of Gdańsk and a recipient of the 2017 Foundation for Polish Science Prize.

He has been conducting pioneering research on the use of regulatory T cells in the treatment of autoimmune diseases, including type 1 diabetes and multiple sclerosis.

He is also the co-founder, shareholder and CEO of the biotechnology company PolTREG S.A., which develops and commercialises therapies based on TREG cells (PAP)

PAP - Science in Poland

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