PolTREG, a clinical-stage biotechnology company developing cellular therapies for a range of autoimmune diseases, has announced the publishing of datan International Immunopharmacology which suggest that PD-1+ T-cells are a dependable biomarker for efficacy in pediatric early-onset Type-1 diabetes (T1D) patients.
The biomarker can be observed in patients who have been successfully treated with PTG-007 T regulatory cell therapy (Treg), the company’s lead asset. The new results are from a two year immune-monitoring data follow-up of 36 patients who had participated in a randomised, placebo-controlled Phase 1/2 clinical trial.
This three-arm trial had earlier shown that 50% of PTG-007-treated patients in combination with rituximab were still in remission after 24 months.
PolTREG CEO Piotr Trzonkowski, who co-authored the peer-reviewed study, said: “This peer-reviewed scientific publication adds to our growing excitement about the potential of polyclonal Treg therapies. We have treated over 100 patients with our cell therapy at our facility over the last 17 years. This has afforded us a wealth of data and unrivalled experience with how T1D and other autoimmune diseases respond to various treatments, including our polyclonal Treg cell therapies and - starting next year - engineered Treg therapeutics. Having a biomarker of efficacy, like PD-1+ T-cells, could facilitate doctors’ ability to monitor their patients’ responses to therapy.”
The main finding of the Phase 1/2 study, results of which were published in 2022, was that combined treatment with Tregs and rituximab is superior to monotherapy in T1D.
The current study aimed to assess the immune profile in patients by setting up immunophenotypes of Treg, effector, and T cells, trying to correlate them with the clinical and biomarker outcomes. The main findings were the following:
- A clinical response in T1D to treatment with polyclonal Treg cells and rituximab is associated with increased percentages of PD-1+ T-cells (both T-reg and T-effector cells), and remodelled humoral immunity
- Increased levels of PD-1+ T-cells correlated with successful treatment and should be confirmed through further study as a biomarker of efficacy
- Higher expression of PD-1 receptor on T-cells also correlated with a better response in patients, such as needing a lower daily dose of insulin.
- Monitoring PD-1+ T-cells may enable immune monitoring of the therapy