MSC Manufacturing for Academic Clinical Trials: From a Clinical-Grade to a Full GMP-Compliant Process

Abstract

Following European regulation 1394/2007, mesenchymal stromal cell (MSCs) have become an advanced therapy medicinal product (ATMP) that must be produced following the good manufacturing practice (GMP) standards. We describe the upgrade of our existing clinical-grade MSC manufacturing process to obtain GMP certification. Staff organization, premises/equipment qualification and monitoring, raw materials management, starting materials, technical manufacturing processes, quality controls, and the release, thawing and infusion were substantially reorganized. Numerous studies have been carried out to validate cultures and demonstrate the short-term stability of fresh or thawed products, as well their stability during long-term storage. Detailed results of media simulation tests, validation runs and early MSC batches are presented. We also report the validation of a new variant of the process aiming to prepare fresh MSCs for the treatment of specific lesions of Crohn's disease by local injection. In conclusion, we have successfully ensured the adaptation of our clinical-grade MSC production process to the GMP requirements. The GMP manufacturing of MSC products is feasible in the academic setting for a limited number of batches with a significant cost increase, but moving to large-scale production necessary for phase III trials would require the involvement of industrial partners.

Keywords: ATMP manufacturing; GMP; MSC; cell therapy; mesenchymal stromal cells.

Figure 1

Manufacturing process and quality controls: from +/− 50 mL of initial fresh BM; MNC cells were isolated by automated Ficoll isolation and seeded in flasks or cellstacks. After passage 0 (P0) expansion during 14 days, cells were harvested and re-loaded in new cellstacks for P1 expansion. One week later, cells were harvested and re-loaded according to the same scheme for P2. Quality controls were performed at different stages of the process. After a first release at passage 2, cells can be either replated or immediately frozen (holding time). Fresh cells are harvested seven days later while frozen cells can be thawed and re-seeded in culture for seven more days before harvesting, and either frozen or formulated and freshly infused into patients. Cells from the same batch can be divided in the different pathways of the process.