Human bone marrow-derived, pooled, allogeneic mesenchymal stromal cells manufactured from multiple donors at different times show comparable biological functions in vitro, and in vivo to repair limb ischemia

Abstract

Background We have previously demonstrated that a pooled population of bone marrow-derived, allogeneic mesenchymal stromal cells (BMMSC), Stempeucel®-1, produced under good manufacturing practices (GMP) conditions, showed clinical efficacy and safety in patients suffering from critical limb ischemia (CLI) due to Buerger’s disease. While Stempeucel®-1 is currently used for CLI and other clinical indications, we wanted to ensure that the product’s continuity is addressed by developing and characterizing a second generation of pooled product (Stempeucel®-1A), manufactured identically from second BM aspirates of the same three donors after a 2-year interval. Methods The two versions of Stempeucel® were manufactured and subjected to gene and protein expression analysis. The nature of various growth factors/cytokines secreted and immunomodulatory activity of these two cell populations were compared directly by various in vitro assays. The preclinical efficacy of these two cell types was compared in an experimental model of hind limb ischemia (HLI) in BALB/c nude mice. The reversal of ischemia, blood flow, and muscle regeneration were determined by functional scoring, laser Doppler imaging, and immunohistochemical analyses. Results Qualitative and quantitative analyses of genes and proteins involved in promoting angiogenic activity and immune regulatory functions revealed high levels of correlation between Stempeucel®-1 and Stempeucel®-1A cell populations. Moreover, intramuscular (i.m) administration of these two cell products in the ischemic limbs of BALB/c nude mice showed significant repair (≥ 70%) of toe and foot necrosis, leading to improved ambulatory function and limb salvage. Furthermore, a biodistribution kinetics study showed that Stempeucel®-1 was mostly localized in the ischemic muscles of mice for a significantly longer time compared to normal muscles, thus playing an essential role in modulating and reversing HLI damage. Conclusions This study shows that with a reproducible manufacturing procedure, it is possible to generate large numbers of pooled mesenchymal stromal cells from human bone marrow samples to establish product equivalence. We conclude from these results that, for the first time, two pooled, allogeneic BMMSC products can be repeatedly manufactured at different time intervals using a two-tier cell banking process with robust and comparable angiogenic properties to treat ischemic diseases.

Pooled human bone marrow-derived mesenchymal stromal cells with defined trophic factors cargo promote dermal wound healing in diabetic rats by improved vascularization and dynamic recruitment of M2-like macrophages

“…Donor-to-donor variability and extensive in vitro expansion are major drivers of inconsistent results from clinical trials, particularly when hMSCs batches are manufactured from single donors (3,56). Pooling single donations, a concept implemented for platelet concentrates for many years (57), has been introduced recently for both hMSC and hPL products (13,16,19,20,25,58). To balance the needs for scale-up and low-level expansion of a pooled hMSC product, our concept starts with MCBs from single donor hMSCs.…”

“…We argued about the best pooling time point. C o n t r a r y t o " M S C -F F M " , p o o l e d a s M N C s , a n d "Stempeucel ® ", pooled at passage 1 followed by five to six expansion passages (17,20), we compared pooling at passage 1, 2 and 3. As expected, the in vitro tests showed that quality did not differ significantly between the different hMSC pools.…”

“…This was then further expanded for five passages until the final product was cryopreserved. While the pooled "MSC-FFM" product requires establishing a new pooled hMSC MCB from scratch, the single-donor "Stempeucel ® " hMSCs MCB concept allows high batch-tobatch consistency as recently shown (20). Yet, replicative aging within the five passages until reaching final product formulation may affect the quality of the clinical product (21).…”

Phase IV Postmarketing Surveillance Study Shows Continued Efficacy and Safety of Stempeucel in Patients with Critical Limb Ischemia Due to Buerger's Disease

“…The reason for continued efficacy of Stempeucel after a single administration was the localized injection of cells at the site of ischemia (infrapopliteal region); these cells predominantly stay localized at the injection site for a minimum duration of 28 days, as shown in our biodistribution studies conducted in a limb ischemia murine model using labeled cells. 30 Stempeucel is capable of secreting a variety of bioactive factors with diverse functional activity, especially those that have been implicated in angiogenesis and anti‐inflammatory properties, such as VEGF, TGF‐β, HGF, angiopoietin 1 and 2, IL‐8, Indoleamine 2,3‐DiOxygenase (IDO), and Prostaglandin E2 (PGE2), among others. This may result in continued improvement as seen in these patients.…”

New idea to promote the clinical applications of stem cells or their extracellular vesicles in central nervous system disorders: Combining with intranasal delivery

“…The source of stem cells or EVs is regarded as another problem, since the isolation and expansion of autologous stem cells commonly used in clinical trials are inconvenient and time-consuming. However, commercial allogeneic stem cells like Stempeucel® began available and used in clinical recently 66 , 67 . These commercial cells could be a source in the future.…”