Cited by 322CAR-T cell therapy researchImmunotherapy and Immune ResponsesVirus-based gene therapy research

The DOI matches its Crossref record; 143 of the 144 references it cites were found in a registry or an index; 61 of the 111 sources its claims cite were checked for support.

Scalable Manufacturing of CAR T Cells for Cancer Immunotherapy

Open access

Published version of a preprint

Abstract

As of April 2021, there are five commercially available chimeric antigen receptor (CAR) T cell therapies for hematologic malignancies. With the current transition of CAR T cell manufacturing from academia to industry, there is a shift toward Good Manufacturing Practice (GMP)–compliant closed and automated systems to ensure reproducibility and to meet the increased demand for patients with cancer. In this review, we describe current CAR T cell clinical manufacturing models and discuss emerging technologic advances that embrace scaling and production optimization. We summarize measures being used to shorten CAR T cell manufacturing times and highlight regulatory challenges to scaling production for clinical use. Significance: As the demand for CAR T cell cancer therapy increases, several closed and automated production platforms are being deployed, and others are in development. This review provides a critical appraisal of these technologies, which can be leveraged to scale and optimize the production of next-generation CAR T cells. See related video: https://aacrjournals.org/content/webinar-car-t-cell-manufacturing

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

This review summarizes current autologous CAR T-cell manufacturing and emerging closed, automated, and allogeneic platforms intended to scale production. It highlights efforts to shorten manufacturing and QC times while noting regulatory, cost, and variability barriers.

Key findings

  • As of April 2021, five commercial CAR T-cell therapies are approved; approved products are second-generation CARs incorporating CD28 or CD137 (4-1BB) co-stimulation, and they achieved complete responses in 32–67% of lymphoma patients, with better CR rates in leukemia.
  • By 2026, commercial CAR T-cell therapies are projected to comprise the largest share of oncology drug sales in pediatric and young adult patients with ALL (44%) and adults with DLBCL (46%).
  • Rapid manufacturing approaches include the FasT CAR platform, which reduced cell culture time to less than 24 hours; in 10 adolescent and adult patients with CD19+ relapsed/refractory B-ALL, 10/10 (100%) achieved CR on day 15, with only one patient experiencing CRS. Sleeping Beauty–generated CAR T cells shortened ex vivo culture to 14 days, with median CAR expression upon infusion of 86% (range 19%–97%) in six patients.
  • Non-viral piggyBac transfection was associated with lymphoma arising from piggyBac-transfected CAR T cells in two of nine patients with relapsed or refractory B-cell malignancies who achieved complete remission; analysis showed increased transgene copy numbers but no integration in typical oncogenes.

Methods

  • Narrative review of clinical CAR T-cell manufacturing models, emerging scaling and automation technologies, genetic modification strategies, quality control, and regulatory considerations.
  • Synthesizes published literature, clinical trial reports, and regulatory documents; no primary experimental data or systematic search methodology is described.

Limitations

  • The paper does not state limitations of the review itself. It extensively discusses field limitations: variability in autologous starting material, open/manual processing, batch-to-batch variation, contamination and human error, viral vector cost and time, expensive closed systems with single-product runs and supply-chain risk, and regulatory discrepancies.
  • Evident from the text: as a narrative review, it lacks systematic search criteria, meta-analysis, and primary data; cited trial results and projections come from external sources.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1158/2643-3230.bcd-21-0084

Cites

143 of 144 references verified1 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

20 Own interpretation · 13 No full text of the sources · 12 Partly supported · 12 Couldn’t confirm · 8 No basis given · 5 Not checked yet · 3 Sources not found · 2 Supported · 2 Supported so far · 1 Not supported · accuracy not yet measured

Verify all 14 references — free account

Show all 30 claims

  • It may state two separate claims as one. 36
  • Probably not a substantial claim. 20
48 of 48
  • The paper relies on this without support.

    The demand for CAR T cell therapies will continue to increase, including for solid tumors, making scalable manufacturing necessary.

    “As demand for CAR T cell therapies increases, particularly when therapies for solid tumors have reached commercial stages, developing manufacturing platforms that enable scaling while embracing the principles of “quality by design,” will be crucial.”
  • The paper relies on this without support.

    Cells from healthy donors have not been exposed to chemotherapies and are free of tumor cells.

    “Since cells from healthy donors have not been exposed to chemotherapies and are free of tumor cells, their quality is expected to be superior to those obtained from cancer patients.”
  • The paper relies on this without support.

    Shortening CAR T cell manufacturing time will enable patients with aggressive disease to receive treatment sooner.

    “Shortening CAR T cell manufacturing time will enable patients with aggressive disease to receive treatment sooner.”
  • The paper relies on this without support.

    Among QC parameters, sterility tests require the most time.

    “Of these parameters, the sterility tests require the most time.”
  • The paper relies on this without support.

    Currently, compendial product sterility tests take 14 days, and the fungal assay can take up to 42 days.

    “Currently, the compendial product sterility tests take 14 days, and the fungal assay can take up to 42 days.”
  • The paper relies on this without support.

    Anaerobic and aerobic enriched media testing that takes 7 days is recognized by the European Pharmacopeia as an alternative rapid test.

    “Anaerobic and aerobic enriched media testing that takes 7 days is recognized by the European Pharmacopeia as an alternative “rapid” test.”
  • The paper relies on this without support.

    The FDA does not formally recognize rapid tests.

    “However, the FDA does not formally recognize rapid tests.”
  • The paper relies on this without support.

    Most manufacturers characterize the final CAR T-cell product by flow cytometry, with many characterization panels currently in use.

    “Most manufacturers characterize the final CAR T-cell product by flow cytometry, with many characterization panels currently in use.”
  • The paper relies on this without support.

    Qualification and validation of the assay are required prior to obtaining a BLA, which is needed in the U.S. for commercial manufacturing.

    “Qualification and validation of the assay are required prior to obtaining a BLA, which is needed in the U.S for commercial manufacturing.”
  • The paper relies on this without support.

    Currently, each manufacturer specifies their own potency assay and develops specific parameters in agreement with regulatory agencies for their clinical grade product.

    “Currently, each manufacturer specifies their own potency assay and develops, in agreement with the regulatory agencies, specific parameters appropriate for the clinical grade product they manufacture.”
  • The paper relies on this without support.

    To date, there is no consensus on a potency assay or platform that can accurately predict clinical response to CAR T cell therapy.

    “To date, there is no consensus on a potency assay or platform that can accurately predict clinical response to CAR T cell therapy.”
  • The paper relies on this without support.

    Variable gene expression is unavoidable in current CAR T cell generation protocols owing to retro- and lentiviral vector integration.

    “While variable gene expression is unavoidable in current CAR T cell generation protocols owing to retro- and lentiviral vectors integration, variabilities in other manufacturing parameters can be better controlled by adopting “Quality by Design” (QBD) principles (Figure 4).”
  • The paper relies on this without support.

    Clinical-grade reagents add to overall costs but are necessary to ensure quality of administered CAR T cell products.

    “These reagents add to the overall costs but are necessary to ensure the quality of the administered CAR T cell products.”
  • The paper relies on this without support.

    Properly trained production and QC staff under GMP conditions is a key element in product manufacture.

    “Production and QC staff properly trained to work under GMP conditions is another key element in product manufacture.”
  • The paper relies on this without support.

    CIRM recognizes the need for training a GMP workforce and offers educational grants to train students on cell therapy manufacturing.

    “This need has also been recognized by the California Institute for Regenerative Medicine (CIRM), which offers educational grants to train students on cell therapy manufacturing.”
  • The paper relies on this without support.

    In the United States, the FDA requires demonstration of safety and substantial evidence of efficacy from clinical trials, and data from these trials are used to apply for a BLA.

    “In the United States, the FDA requires the demonstration of safety and substantial evidence of efficacy from clinical trials. Data from these trials are then used to apply for a Biologics License Application (BLA).”
  • The paper relies on this without support.

    For Phase 2 or 3 clinical trials, the FDA more tightly regulates the process.

    “For Phase 2 or 3 clinical trials, however, the FDA more tightly regulates the process.”
  • The paper relies on this without support.

    Gene-modified cellular products are subjected to greater regulatory scrutiny in the E.U. than non-gene modified therapies.

    “Also, gene-modified cellular products are subjected to greater regulatory scrutiny in the E.U. than non-gene modified therapies.”
  • The paper relies on this without support.

    Developers have been keen on setting up production facilities in the respective geographical areas to fully comply with the local regulatory landscape.

    “Therefore, developers have been keen on setting up production facilities in the respective geographical areas to fully comply with the local regulatory landscape.”
  • The paper relies on this without support.

    To increase accessibility of autologous CAR T cell products, some therapies in development are transitioning toward decentralized manufacturing.

    “To increase the accessibility of autologous CAR T cell products, some therapies in development are transitioning toward decentralized manufacturing.”
  • The paper relies on this without support.

    Novel approaches to shorten the manufacturing process are being developed, such as non-viral vector approaches relying on electroporation of primary cells.

    “Finally, novel approaches to shorten the manufacturing process are being developed, such as non-viral vector approaches relying on electroporation of primary cells.”
21 of 21

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Citations

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Metadata

Authors
Abou-el-Enein, M., Elsallab, M., Feldman, S. A., Fesnak, A. D., Heslop, H. E., Marks, P., Till, B. G., Bauer, G., & Savoldo, B.
Affiliations
  • 1Division of Medical Oncology, Department of Medicine, and Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.
  • University of Southern California (US)
  • Stanford Cancer Institute (US)
  • University of Pennsylvania (US)
  • Houston Methodist (US)
  • Center for Biologics Evaluation and Research (US)
  • Fred Hutch Cancer Center (US)
  • University of California, Davis (US)
  • University of North Carolina at Chapel Hill (US)
Venue
Blood Cancer Discovery
Published
2021-08-03
Volume
2
Issue
5
Pages
408-422
ISSN
  • 2643-3230 (ISSN-L)
  • 2643-3249
OpenAlex
W3190521604
Cited by
321
References
143
Citations by year
2026: 79 · 2025: 81 · 2024: 81 · 2023: 37 · 2022: 41 · 2021: 2
FWCI
4.88
Type
journal article
Language
en
Open access
Locations
  • Blood Cancer Discovery (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • NCI (P50CA126752)
  • American Association for Cancer Research (SU2C-AACR-DT-29–19)
Topics
  • Health Sciences › Medicine › Oncology › CAR-T cell therapy research
  • Life Sciences › Immunology and Microbiology › Immunology › Immunotherapy and Immune Responses
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Virus-based gene therapy research
Keywords
chimeric antigen receptor T cells, chimeric antigen receptor, T cell manufacturing, scalable fabrication, good manufacturing practices, hematologic malignancies, production time reduction, regulatory challenges, production optimization
MeSH terms
Humans, Neoplasms, T-Lymphocytes, Reproducibility of Results, Immunotherapy, Adoptive

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