G-Rex® for CAR-T Cell Therapy
Build your CAR-T manufacturing process around a simple, modular and linearly scalable platform designed to integrate activation, transduction, expansion and other unit operations - from early process development through commercial manufacturing.
The Value of Simplicity
CAR-T manufacturing is inherently complex. It requires coordinated logistics followed by a sequence of enrichment, activation, genetic engineering, expansion, harvest, and formulation. The sophistication of the therapy does not require equal complexity from the manufacturing platform.
G-Rex® simplifies the process by allowing cells to access oxygen and nutrients through passive mechanisms rather than pumps, perfusion circuits, or bespoke culture instrumentation (just a standard incubator). That simpler foundation gives manufacturers greater freedom to assemble the technologies, reagents, and unit operations that best fit their therapy.
Passive oxygenation, nutrient delivery, and waste dilution reduce dependence on mechanical agitation systems. Fewer variables to control when assuring drug product quality means greater clarity and focus on the process parameters that are truly critical.
Published workflows have demonstrated that major unit operations - including T cell enrichment, activation, transduction, expansion, concentration, and harvest - can be integrated around a common vessel architecture.
G-Rex®'s linear scalability supports reduced-scale model development for cost-effective and expeditious process development and continuous improvement, while its modularity enables efficient scale-out through parallelization and cycle-time reduction.
The Gold Standard
From the institutions that pioneered CAR-T cell therapy to the manufacturers bringing it to patients at commercial scale, G-Rex® has become a foundational manufacturing platform for the field.
Stanford Medicine, Penn, NIH/NCI, UCSF, USC/CHLA, Seattle Children’s and other leading cell therapy programs have publicly documented the use of G-Rex® in CAR-T development and manufacturing. At Seattle Children’s alone, G-Rex® has been used to manufacture cell therapies for hundreds of clinical trial participants.
Today, G-Rex® is used to make six commercially approved cell therapies and leading CAR-T cell therapies bringing hope to thousands of cancer patients.
Academics
Biotechs
Commercially Approved
Leading Car-T Manufacturer
Leading Car-T Manufacturer in China & Singapore
A Typical Process
Across published CAR-T workflows, G-Rex® has been used to integrate enrichment, activation, viral and non-viral genetic engineering, expansion, concentration, and harvest while remaining compatible with a broad range of ancillary technologies and reagents.
G-Rex® provides a simple, modular foundation around which those choices can be assembled - allowing individual unit operations to evolve without requiring the entire manufacturing platform to change.
Starting material is most often collected by apheresis and transported to a hospital-based, regional, or centralized manufacturing facility. Whole blood can also provide sufficient T cells for G-Rex® CAR-T manufacturing and may reduce the procedural burden, infrastructure requirements, and travel associated with apheresis—particularly for pediatric patients.
Hear Caring Cross’s Dr. Boro Dropulić present on Using Whole Blood for Adult CAR-T Manufacturing
G-Rex® accommodates both in-vessel and instrument-based enrichment. SepaRex® integrates CTS™ Detachable Dynabeads™ directly within G-Rex®. For users already invested in instruments such as Prodigy® or MARS® Bar, enriched T cells can be eluted directly into G-Rex®, freeing the instrument for another batch and increasing throughput and return on investment.
Hear Stanford CCT’s Dr. Ramya Tunuguntla present on Integrated T-Cell Enrichment in G-Rex
G-Rex® is compatible with standard soluble activation reagents, including TransAct™ and ImmunoCult™, as well as CTS™ Dynabeads™ and CTS Detachable Dynabeads. When starting with peripheral blood mononuclear cells rather than enriched T cells, Bio-Techne GMP anti-CD3 and anti-CD28 antibodies provide an additional soluble activation strategy.
G-Rex® supports lentiviral and retroviral transduction. Transduction enhancers such as RetroNectin® can improve transduction efficiency and simplify the workflow by enabling static transduction without spinoculation. G-Rex® also integrates with electroporation-based engineering using CRISPR/Cas9 and transposon systems such as TcBuster®, Sleeping Beauty, and piggyBac.
Expansion duration in G-Rex® can be tailored to the needs of the therapy—from ultra-rapid processes to conventional workflows that typically reach maximum cell density within 7–10 days. G-Rex® accommodates different media, cytokines, feeding strategies, and manufacturing endpoints without changing the fundamental expansion platform.
Hear UPENN’s Dr. Saba Ghassemi present on Rapid CAR-T Manufacturing in G-Rex
G-Rex® supports closed-system cell harvest using conventional transfer and separation technologies. GatheRex® enables controlled media removal and in-vessel concentration while cells remain settled on the gas-permeable membrane, reducing the volume transferred into downstream washing, concentration, formulation, or fill-and-finish equipment.
G-Rex® can connect with commonly used downstream washing, concentration, and formulation systems, including Fresenius Kabi’s LOVO® and Cue®, Thermo Fisher Scientific’s Rotea™ and Compleo™, and Cytiva’s Sepax™ C-Pro. The formulated CAR-T drug product can then be filled into weldable bags, CellSeal® vials, or other containers selected for fresh or cryopreserved administration.
Recommended Products
From process development through commercial manufacturing, the G-Rex® product family provides a common platform for developing, scaling, and operating CAR-T manufacturing processes.
Select the vessel 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 are accepted by the various regulatory authorities as qualified reduced scale models representative of clinical-scale bioreactors. Multi-well plate formats, with surface areas as low as 2cm2, enables design space establishment in the most time and cost-efficient manner.
The G-Rex® bioreactor is the clinical-scale engine of CAR-T manufacturing. Gas-permeable containers that deliver unlimited oxygen through a silicone membrane, enabling robust T cell expansion without perfusion, agitations, or shear stress, producing therapeutically relevant doses with a simpler, more consistent process than mechanized bioreactor platforms.
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.
GMP T cell media, GMP Human AB Serum, and GMP cytokines (IL-2, IL-7, IL-15, and IL-21) are all available in the right formats and right aliquots for G-Rex® centric CAR-T cell manufacturing.
Next Steps
Whether you are building a new CAR-T process, transitioning an existing process to G-Rex®, or optimizing a mature manufacturing workflow, our team can help identify the most practical path forward.
Frequently Asked Questions
G-Rex® relies on passive gas exchange and a large media reservoir to provide cells with access to oxygen and nutrients without pumps, perfusion circuits, or dedicated culture instrumentation beyond a standard incubator.
No. G-Rex®-centered CAR-T workflows have incorporated enrichment, activation, viral transduction, non-viral genetic engineering, expansion, concentration, and harvest.
Yes. Closed-system G-Rex® bioreactors and complementary technologies are available for clinical and commercial manufacturing workflows.
Yes. G-Rex® formats allow process parameters developed at reduced scale to be translated into larger manufacturing formats using the same fundamental vessel architecture.
Yes. Published CAR-T processes have demonstrated G-Rex® compatibility with retroviral and lentiviral transduction as well as non-viral genome-engineering approaches.
Yes. The appropriate transition strategy depends on the maturity of the process, existing manufacturing platform, and regulatory stage. A G-Rex® Optimization Specialist can help evaluate the technical and comparability considerations.
Not typically. In standard CAR-T workflows, the media capacity (10mL/cm2) of G-Rex® can eliminate the need for frequent feeding or media exchange. In some workflows that add certain molecules (e.g. small-molecules for CAR enrichment) with poor or unknown stability, a media exchange or supplementation may be necessary, and therefore it depends on the specific CAR-T process.
Traditional approaches include sampling the supernatant to obtain media samples and correlating metabolite concentrations (e.g. glucose and lactate) to viable cell densities (cells/cm2). SMART G-Rex® and SensoRex® provide an integrated, non-invasive option for monitoring cell growth without physically sampling the culture.
The appropriate format depends on development stage, starting cell number, target dose, process duration, and manufacturing strategy. Reduced-scale and manufacturing-scale formats allow the platform to be matched to the needs of the program.
A G-Rex® Optimization Specialist can review your existing or proposed process and help identify an appropriate development, transition, optimization, or scale-up strategy.
Have a different question? Connect with a G-Rex® Optimization Specialist.
Evidence & References
Explore the published evidence supporting the use of G-Rex® across virus-specific T-cell research, development, and clinical manufacturing.
