PolTREG Treg cell therapy for patients with type 1 diabetes shows long-term clinical remission and insulin independence Page 1

• Cell therapy with PTG-007 resulted in clinical remission for up to 12 years in some patients
• Some of the patients remained insulin independent for up to 24 months
• PTG-007 ready to start pivotal study
• Data presented at the INNODIA EASD conference

Gdańsk, Poland – September 9, 2024 – PolTREG SA (Warsaw Stock Exchange: PTG), a clinical-stage biotechnology company developing cell therapies for a range of autoimmune diseases, today announced data showing that treatment with its Treg cell therapy, PTG-007, resulted in clinical remission for up to 12 years in patients with type 1 diabetes (T1D). A subset of these patients remained insulin independent for 18 to 24 months after treatment. The company is presenting the data today at the INNODIA EASD symposium in Madrid.

“People with type 1 diabetes understand the lifelong commitment required for their care. That is why the results of treating patients for such a long period of time with our cellular therapy PTG-007 are so important. Today’s results are extremely encouraging, showing that some patients remain in clinical remission for up to 12 years after initial treatment. This makes us very excited to initiate a pivotal study of PTG-007 as soon as we find a suitable partner. We believe that PTG-007 has the potential to free many type 1 diabetes patients from the lifelong burden of having to take frequent insulin injections and the serious long-term complications of the disease,” said Prof Piotr Trzonkowski, Chief Executive Officer of PolTREG.

The clinical study followed 54 patients who had participated in Phase I and Phase II studies of PTG-007 for the treatment of early-onset type 1 diabetes for a period of 7 to 12 years.

The main findings were:

• A proportion of patients treated with PTG-007 remained insulin independent for up to 18 to 24 months after treatment.
• A subgroup of patients was still in clinical remission 7 to 12 years after treatment with Tregs. Clinical remission is defined as a low requirement for external insulin, while maintaining proper metabolic/glycemic control.
• The best results were observed in patients who received Treg therapy in combination with standard anti-CD20 treatment (rituximab), with endogenous insulin levels measured after patients consumed a standardized liquid meal.
• The study analyzed more than 700 variables of cardiac function, microcirculation, kidney, liver, endocrine system, fertility. No inferiority of the variables was found in patients treated with Treg cells compared to standard treatment.

• The study found that the treatment had no serious side effects.

The Company is working towards publishing the study in a peer-reviewed scientific publication, at which stage it will provide full data disclosure. The long-term safety and efficacy results of Treg therapy in T1D presented today represent a significant competitive advantage and pave the way for the Company to initiate a pivotal Phase 2/3 study of PTG-007 for the treatment of T1D, for which it is currently seeking partnership funding.