Polyclonal Regulatory T Cell Manufacturing Under cGMP: A Decade of Experience.

Joanna Balcerek,Luis Acevedo,Jonathan H Esensten,Amy L Putnam,Qizhi Tang,Weihong Liu,Jeffrey A Bluestone,Brian R Shy,Angela Lares,Jingying Xu,Lisa M Masiello,Vinh Nguyen,Michael R Lee,Ashley S Leinbach,Florinna Dekovic,Sreenivasan Paruthiyil

doi:10.3389/fimmu.2021.744763

Joanna Balcerek, Luis Acevedo + Show 14 more

Open Access

https://doi.org/10.3389/fimmu.2021.744763

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Abstract

We report on manufacturing outcomes for 41 autologous polyclonal regulatory T cell (PolyTreg) products for 7 different Phase 1 clinical trials over a 10-year period (2011-2020). Data on patient characteristics, manufacturing parameters, and manufacturing outcomes were collected from manufacturing batch records and entered into a secure database. Overall, 88% (36/41) of PolyTreg products met release criteria and 83% (34/41) of products were successfully infused into patients. Of the 7 not infused, 5 failed release criteria, and 2 were not infused because the patient became ineligible due to a change in clinical status. The median fold expansion over the 14-day manufacturing process was 434.8 -fold (range 29.8-2,232), resulting in a median post-expansion cell count of 1,841 x 106 (range 56.9-16,179 x 106). The main correlate of post-expansion cell number was starting cell number, which positively correlates with absolute circulating Treg cell count. Other parameters, including date of PolyTreg production, patient sex, and patient age did not significantly correlate with fold expansion of Treg during product manufacturing. In conclusion, PolyTreg manufacturing outcomes are consistent across trials and dates of production.

Highlights

Regulatory T cells (Tregs) are a subset of CD4+ T cells that suppress excessive immune activation and prevent autoimmunity [1,2,3,4]
We provide data on 41 in vitro expanded polyclonal CD4+CD127lo/‐CD25+ PolyTreg products manufactured for 7 clinical trials in patients with autoimmune conditions, patients who have undergone kidney transplantation, or patients receiving de novo pancreatic islet transplant
In this summary of manufacturing outcomes for autologous polyclonal Treg products in 7 clinical trials, we show a high rate of success in manufacturing products from different patient populations over a 10-year period

Summary

INTRODUCTION

Regulatory T cells (Tregs) are a subset of CD4+ T cells that suppress excessive immune activation and prevent autoimmunity [1,2,3,4]. We describe our experience manufacturing autologous polyclonal Treg products for patients with autoimmune diseases or transplantation in multiple clinical trials over a 10-year period. The approach to Treg manufacturing used for these patients involves sorting of CD4+CD25+CD127lo/- Treg from peripheral blood mononuclear cells using FACS, following by expansion for 14 days in medium containing IL-2. Stimulation with anti-CD3/CD28 beads is provided on days 0 and 9 of the expansion These data provide insight into the effects of intrinsic patient variability and patient disease status on Treg manufacturing outcomes. We provide data on 41 in vitro expanded polyclonal CD4+CD127lo/‐CD25+ PolyTreg products manufactured for 7 clinical trials in patients with autoimmune conditions, patients who have undergone kidney transplantation, or patients receiving de novo pancreatic islet transplant. We quantify manufacturing outcomes and describe significant correlations using detailed records of patient characteristics, manufacturing parameters, and cell manufacturing outcomes

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