In vivo safety profile and biodistribution of GMP-manufactured human skin-derived ABCB5-positive mesenchymal stromal cells for use in clinical trials

Abstract

Background aims. Human dermal ABCB5-expressing mesenchymal stromal cells (ABCB5 + MSCs) represent a promising candidate for stem cell based therapy of various currently uncurable diseases in several fields of regenerative medicine. We have developed and validated a method to isolate, from human skin samples, and expand ABCB5 + MSCs that meet the guideline criteria of the International Society for Cellular Therapy. We are able to process these cells into a Good Manufacturing Practice conforming, MSC-based advanced-therapy medicinal product. Methods. To support the development of ABCB5 + MSCs for potential therapeutic topical, intramuscular and intravenous administration, we have tested our product in a series of Good Laboratory Practice compliant nonclinical in-vivo studies addressing all relevant aspects of biosafety, including potential long-term persistence and proliferation, distribution to nontarget tissues, differentiation into undesired cell types, ectopic tissue formation, tumor formation and local tissue reaction. Results. (i) Subcutaneous application of 1 × 10 7 ABCB5 + MSCs/animal and intravenous application of 2 × 10 6 ABCB5 + MSCs/animal, respectively, to immunocompromised mice did not result in safety-relevant biodistribution, persistence or proliferation of the cells; (ii) three monthly subcutaneous injections of ABCB5 + MSCs at doses ranging from 1 × 10 5 to 1 × 10 7 cells/animal and three biweekly intravenous injections of 2 × 10 6 ABCB5 + MSCs/animal, respectively, to immunocompromised mice were nontoxic and revealed no tumorigenic potential; and (iii) intramuscular injection of 5 × 10 6 ABCB5 + MSCs/animal to immunocompromised mice was locally well tolerated. Discussion. The present preclinical in vivo data demonstrate the local and systemic safety and tolerability of a novel advanced-therapy medicinal product based on human skin-derived ABCB5 + MSCs.

Process Development and Safety Evaluation of ABCB5+ Limbal Stem Cells as Advanced-therapy Medicinal Product to Treat Limbal Stem Cell Deficiency

“…4b). Regarding the cells' biological activity, it had to be ruled out that the brin gel could create a hypoxic environment that, in turn, would stimulate the LSCs to secrete proangiogenic factors such as VEGF, as is known, e.g., for ABCB5 + mesenchymal stem cells [30]. Such adaptive secretion of proangiogenic factors would facilitate angiogenesis and thus jeopardize therapeutic success.…”

Mesenchymal Stem Cells Beyond Regenerative Medicine

“…Cell yields are then sorted with antibody-coupled magnetic beads, and cultured MSCs are validated according to ISCT criteria. Finally, several tests are performed to assess in vivo toxicity, tumorigenicity, and biodistribution/persistence (Tappenbeck et al, 2019). The data of another clinical study, which warranted its authors an "orphan designation" in Germany for graft-versus-host disease (GvHD) treatment using MSCs, authenticate the effectiveness of such protocol.…”

“…This preclinical success permitted the transit to human studies, with no records of toxicity or tumorigenicity with the use of GMP-compliant human MSCs suitable for clinical trial use (Tappenbeck et al, 2019). Up to this date, 921 clinical studies employing MSCs as the primary intervention have been registered, 704 of which date between 2011 and 2019 (U. S. National Library of Medicine, 2019).…”

Allogene, mesenchymale Stammzellen zur Behandlung des akut-auf-chronischen Leberversagens – Initiierung der allo-APZ2-ACLF-II-01-Studie

“…73 % erheblich [3,4]. [11,12]. Die Zellen werden intravenös in einer Dosierung von 2 × 10 6 Zellen/kg transfundiert.…”