Automation of cellular therapy product manufacturing: results of a split validation comparing CD34 selection of peripheral blood stem cell apheresis product with a semi-manual vs. an automatic procedure.

Christiane Hümmer,Mike Essl,Erhard Seifried,Volker Huppert,Belinda Stock,Halvard Bonig,Eva Wingenfeld,Kristina Reck,Juliane Stuth,Carolin Poppe,Milica Bunos

doi:10.1186/s12967-016-0826-8

Abstract

BackgroundAutomation of cell therapy manufacturing promises higher productivity of cell factories, more economical use of highly-trained (and costly) manufacturing staff, facilitation of processes requiring manufacturing steps at inconvenient hours, improved consistency of processing steps and other benefits. One of the most broadly disseminated engineered cell therapy products is immunomagnetically selected CD34+ hematopoietic “stem” cells (HSCs).MethodsAs the clinical GMP-compliant automat CliniMACS Prodigy is being programmed to perform ever more complex sequential manufacturing steps, we developed a CD34+ selection module for comparison with the standard semi-automatic CD34 “normal scale” selection process on CliniMACS Plus, applicable for 600 × 106 target cells out of 60 × 109 total cells. Three split-validation processings with healthy donor G-CSF-mobilized apheresis products were performed; feasibility, time consumption and product quality were assessed.ResultsAll processes proceeded uneventfully. Prodigy runs took about 1 h longer than CliniMACS Plus runs, albeit with markedly less hands-on operator time and therefore also suitable for less experienced operators. Recovery of target cells was the same for both technologies. Although impurities, specifically T- and B-cells, were 5 ± 1.6-fold and 4 ± 0.4-fold higher in the Prodigy products (p = ns and p = 0.013 for T and B cell depletion, respectively), T cell contents per kg of a virtual recipient receiving 4 × 106 CD34+ cells/kg was below 10 × 103/kg even in the worst Prodigy product and thus more than fivefold below the specification of CD34+ selected mismatched-donor stem cell products. The products’ theoretical clinical usability is thus confirmed.ConclusionsThis split validation exercise of a relatively short and simple process exemplifies the potential of automatic cell manufacturing. Automation will further gain in attractiveness when applied to more complex processes, requiring frequent interventions or handling at unfavourable working hours, such as re-targeting of T-cells.

Highlights

Automation of cell therapy manufacturing promises higher productivity of cell factories, more economical use of highly-trained manufacturing staff, facilitation of processes requiring manufacturing steps at inconvenient hours, improved consistency of processing steps and other benefits
The specific technical challenge of the overall relatively simple CD34 selection process is the near-homogeneous enrichment of stem cells with minimal contamination by non-target cells that can be achieved with magnet, column and reagent, components which are shared by both systems
Platelets are removed by soft spins of the apheresis product in centrifuge bags, leukocytes are incubated with CD34 reagent, excess reagent is removed by successive washes, after which the cell suspension is applied to the CliniMACS Plus which performs an automatic column selection and elution into the target cell bag

Summary

Introduction

Automation of cell therapy manufacturing promises higher productivity of cell factories, more economical use of highly-trained (and costly) manufacturing staff, facilitation of processes requiring manufacturing steps at inconvenient hours, improved consistency of processing steps and other benefits. Previous analyses comparing outcomes of CD34 selections with the “largescale” process on Prodigy versus on CliniMACS Plus had suggested greater non-target cell reduction in CliniMACS Plus products [4, 5]. In light of these data, the manufacturer re-designed the process on Prodigy with the aim to further reduce non-target cells. The process became scalable, as the “normal-scale” module was introduced which uses only one vial of CliniMACS CD34 reagent This allows for magnetic labelling at reduced material costs for smaller cell products of not more than 600 × 106 CD34+ cells and 60 × 109 WBCs. The “normal scale” Prodigy process was tested here for the first time. The manuscript presents several novelties about the automatic Prodigy CD34 selection process, albeit each one modest, namely, split validation, first reported use of the re-designed “LP-34 Enrichment” process and first reported use of the “normal scale” module

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