Process development and safety evaluation of ABCB5+ limbal stem cells as advanced-therapy medicinal product to treat limbal stem cell deficiency

Table 2 Specifications and results from GMP batch analysis (n = 13)

Parameter	Test method	Specification	Mean	Deviations from specification
Parameter	Test method	Specification	Mean	Absolute	Percentage
ABCB5⁺ cell content	Flow cytometry	≥ 90%	96.4%	0	0%
Mycoplasma	Nucleic acid test-based assay (2.6.7 Ph. Eur.)	not detectable (< 10 CFU/ml)	< 10 CFU/ml	0	0%
Endotoxin level	LAL-Test (2.6.14 Ph. Eur.)	≤ 2 EU/ml	≤ 2 EU/ml	0	0%
Cell vitality	Flow cytometry (2.7.29 Ph. Eur.)	≥ 90%	97.5%	1	7.7%
Cell viability	Flow cytometry (2.7.29 Ph. Eur.)	≥ 90%	99.2%	0	0%
Bead residues	Flow cytometry	≤ 0.5%	0.04%	0	0%
Microbiological control (n = 12)^a)	BacT/ALERT® System (adapted to 2.6.27 Ph. Eur.)	no growth	n.a.	0	0%
p63⁺ cell content	Immunofluorescence	≥ 20%	76,7%	0	0%
PAX6⁺ cell content (n = 8)^b)	Immunofluorescence	≥ 50%	71.3%	0	0%

Ph. Eur. European Pharmacopeia, LAL Limulus amebocyte lysate, n.a. not applicable
^aOne batch could not be evaluated due to sample size error and was therefore not released
^bFive batches could not be evaluated due to staining problems and were therefore not released

ISSN: 1757-6512