Process data of allogeneic ex vivo-expanded ABCB5(+) mesenchymal stromal cells for human use: off-the-shelf GMP-manufactured donor-independent ATMP

BACKGROUND: Human dermal mesenchymal stromal cells (MSCs) expressing the ATP-binding cassette (ABC) efflux transporter ABCB5 represent an easily accessible MSC population that, based on preclinical and first-in-human data, holds significant promise to treat a broad spectrum of conditions associated not only with skin-related but also systemic inflammatory and/or degenerative processes. METHODS: We have developed a validated Good Manufacturing Practice-compliant expansion and manufacturing process by which ABCB5(+) MSCs derived from surgical discard skin tissues are processed to an advanced-therapy medicinal product (ATMP) for clinical use. Enrichment for ABCB5(+) MSCs is achieved in a three-step process involving plastic adherence selection, expansion in a highly efficient MSC-selecting medium, and immunomagnetic isolation of the ABCB5(+) cells from the mixed culture. RESULTS: Product Quality Review data covering 324 cell expansions, 728 ABCB5(+) MSC isolations, 66 ABCB5(+) MSC batches, and 85 final drug products reveal high process robustness and reproducible, reliable quality of the manufactured cell therapy product. CONCLUSION: We have successfully established an expansion and manufacturing process that enables the generation of homogenous ABCB5(+) MSC populations of proven biological activity manufactured as a standardized, donor-independent, highly pure, and highly functional off-the-shelf available ATMP, which is currently tested in multiple clinical trials.