G-Rex® for Treg Therapy
The simplest way to assemble quality Treg therapies.
G-Rex® provides a proven, simple, & scalable platform to developers and manufacturers of regulatory T-cell therapies from early research and preclinical development through clinical manufacturing.
The Value of Simplicity
In regulatory T-cell (Treg) therapy, simplicity is the ultimate sophistication.
G-Rex® is proven to allow developers and manufacturers to expand regulatory T-cells from rare starting populations to clinically relevant quantities while preserving the identity, purity, stability, and suppressive function that define the final product.
As isolation, activation, engineering, enrichment, expansion, and cryopreservation add complexity to Treg manufacturing, G-Rex® provides a simple and scalable foundation upon which developers and manufacturers can assemble their unique therapy.
Expand More. Manipulate Less
G-Rex® delivers the large cell numbers Treg therapy demands without the open handling and repeated interventions that introduce contamination risk and process variability
Identity Preserved. Function Intact
G-Rex® expands Tregs to clinical scale without compromising the phenotypic stability and suppressive potency that define the product
Ready to Ship. Ready to Infuse.
G-Rex® supports the full Treg manufacturing journey — including transport and cryopreservation — without adding process complexity at the final, most critical steps.
The Gold Standard
The gold standard for regulatory T-cell therapy.
For more than a decade, leading academic and clinical institutions have used G-Rex® to research, develop, and manufacture regulatory T-cell therapies. Across a growing body of independent publications, G-Rex® has supported natural and engineered Treg programs from early research and preclinical development through GMP and clinical manufacturing.
Collectively, this referenceable base demonstrates the ability of G-Rex® to produce clinically relevant quantities of regulatory T-cells while preserving critical attributes such as identity, purity, viability, stability, and suppressive function. As regulatory T-cell therapy has evolved, G-Rex® has evolved alongside it—establishing the platform as the gold standard for the field.
Academics
Seattle Children’s Research Institute / University of Washington
Charité / Berlin Center for Advanced Therapies
King’s College London
University of Cambridge
University of Oxford
Biotechs
Sonoma Biotherapeutics
Cellenkos
Co-Regen
A Typical Process
Regulatory T-cell therapy manufacturing made simple.
Regulatory T-cell therapies vary by isolation strategy, antigen specificity, engineering approach, and final formulation. Despite these differences, most processes follow a common vein-to-vein manufacturing pathway. G-Rex® provides a simple and scalable foundation around which those choices can be assembled.
Patient
Starts and ends with the patient
Recommended Products
Build your regulatory T-cell manufacturing platform in G-Rex®.
From small-scale research and process development through large-scale clinical manufacturing, the G-Rex® product family provides a common platform for developing, optimizing, and scaling regulatory T-cell manufacturing processes. Select the G-Rex® format and complementary technologies that fit the needs of your process today—with a pathway to evolve as your therapy advances.
G-Rex® Well Plates provide an ideal small-scale platform for Treg process development and enables high-fold expansion while preserving FoxP3 expression and suppressive function. Their multi-well format supports parallel condition testing, making them the go-to tool for optimizing Treg manufacturing protocols before clinical-scale translation
G-Rex® bioreactors enable robust clinical-scale Treg manufacturing in a GMP-compliant, closed system and deliver enhanced expansion rates through gas-permeable membrane technology while maintaining high FoxP3+ purity and suppressive function throughout the culture process.
Single-use, gamma-irradiated bags in 250 mL, 1 L, and 5 L formats with ports and tubing designed to connect directly to closed-system G-Rex® devices, keeping media addition, cell transfer, and harvest inside a closed fluid path. Because that compatibility is engineered in, there are no third-party bag assemblies to source, adapt, or qualify.
A complete GMP reagent ecosystem. Serum-free, xeno-free ExCellerate™ media paired with animal-free GMP IL-2, IL-7, IL-15, and IL-21 give a process consistent bioactivity, closed-system-ready formats, and a direct path from RUO to GMP without a reagent change.
Next Steps
Whatever phase your regulatory T-cell program is in, a G-Rex® Optimization Specialist can help.
Whether you are building a new regulatory T-cell process, transitioning an existing process to G-Rex®, optimizing a mature manufacturing workflow, or preparing to scale, our team can help identify the most practical path forward.
Frequently Asked Questions
Frequently asked questions about G-Rex® for regulatory T-cell therapy.
Why is regulatory T-cell manufacturing challenging?
Tregs represent a small fraction of circulating T-cells and must be isolated and expanded while preserving identity, purity, stability, viability, and suppressive function. Engineering and other additional unit operations can further increase manufacturing complexity.
Small-scale G-Rex® bioreactors are popular among Treg developers and manufacturers because their 5 cm² to 10 cm² gas-permeable surface areas allow them to accommodate low starting cell numbers.
What types of regulatory T-cell therapies have been developed using G-Rex®?
Published studies have used G-Rex® in the development and manufacturing of natural, gene-edited, engineered, and CAR-Treg therapies. This evidence spans early research and preclinical development through GMP and clinical manufacturing.
Has G-Rex® been used for clinical regulatory T-cell manufacturing?
Yes. Published clinical work documents the manufacture and administration of ex vivo expanded regulatory T-cells. The appropriate clinical evidence and claims should remain tied to the specific product, process, study population, and reported outcomes.
Does G-Rex® preserve regulatory T-cell phenotype and function?
Multiple independent studies reported expanded products with Treg-associated phenotypes and retained in vitro—and in some studies in vivo—suppressive activity. Outcomes remain dependent on the full process, including starting material, selection, stimulation, media, cytokines, pharmacologic supplements, culture duration, and harvest criteria.
Can G-Rex® support engineered or CAR-Treg workflows?
Yes. G-Rex® expansion has been incorporated after CRISPR editing, homology-directed repair, lentiviral transduction, and affinity enrichment in published engineered Treg and CAR-Treg workflows. The exact sequence and conditions depend on the product design.
How does a regulatory T-cell process scale in G-Rex®?
The G-Rex® platform maintains consistent geometry across formats, allowing developers to progress from M-series well plates and small-scale G-Rex®5M or G-Rex®10M bioreactors into G-Rex®50M and G-Rex®100M bioreactors.
Which G-Rex® device is appropriate for my regulatory T-cell process?
The right device depends on starting cell number, seeding density, media volume, expansion target, process duration, target dose, closed-system requirements, and desired scale-up or scale-out strategy. A G-Rex® Optimization Specialist can help translate these inputs into an appropriate device and process plan.
Have a different question? Connect with a G-Rex® Optimization Specialist.
Evidence & References
Peer-reviewed evidence from academia and industry.
Explore the published evidence supporting the use of G-Rex® across regulatory T-cell research, development, and clinical manufacturing.
- Chakraborty R, et al. Robust and cost effective expansion of human regulatory T-cells highly functional in a xenograft model of graft-versus-host disease. Haematologica. 2013;98(4):533–537.
- Lei H. Human natural regulatory T-cells subsets: Functional characterization and T-cell receptor repertoire analysis [doctoral dissertation]. Humboldt-Universität zu Berlin; 2014.
- Mathew JM, et al. A phase I clinical trial with ex vivo expanded recipient regulatory T-cells in living donor kidney transplants. Scientific Reports. 2018;8:7428.
- Marín Morales JM, et al. Automated clinical grade expansion of regulatory T-cells in a fully closed system. Frontiers in Immunology. 2019;10:38.
- Frary E, et al. Optimization and scale-up of Treg expansion from CD4 cells in G-Rex®6M plates [poster]. 2020.
- Kaiser D, et al. Freezing medium containing 5% DMSO enhances the cell viability and recovery rate after cryopreservation of regulatory T-cell products ex vivo and in vivo. Frontiers in Cell and Developmental Biology. 2021;9:750286.
- Ellis GI, et al. Generation of non-human primate CAR Tregs using artificial antigen-presenting cells, simian tropic lentiviral vectors, and antigen-specific restimulation. STAR Protocols. 2022;3:101784.
- Shimon O, et al. CRISPR-Cas9 engineering of human T regulatory cells—Design and optimization of a manufacturing process. Molecular Immunology. 2025;184:13–21.
- Tripathi SK, et al. HLA-A2 CAR/IL-2-CISC engineered Treg display robust in vitro and in vivo antigen-specific regulatory function. Molecular Therapy: Methods & Clinical Development. 2025;33.
- Edwards W, et al. Perfusion microbioreactor for CAR-Treg manufacturing. iScience. 2026;29:115246.
- Honaker Y, et al. Preclinical efficacy and safety assessment of engineered regulatory T-cells for treatment of IPEX and other autoimmune disorders. 2026.
- Zarrinrad G, et al. Clinical development of tacrolimus-resistant regulatory T-cells to enable simultaneous immunosuppression and immune regulation. 2026.
- Galinas, P. (2026). CoRegen’s Science and Future Plans [Presentation]. G-Rex® Grant Tour, Houston, TX. ScaleReady.
