Strategy for an abbreviated in-house qualification of a commercially available Rapid Microbiology Method (RMM) for canadian regulatory approval

Abstract

Background aims: Cell therapy products (CTP) typically require full sterility, endotoxin and Mycoplasma testing before product release. Often this is not feasible with fresh cells, and sponsors may rely on rapid microbiological methods (RMM). RMM must be qualified in-house using the sponsor's facilities, equipment, consumables, cells and matrices to meet regulatory approval. Herein, we present a cost-effective strategy to conduct an in-house abbreviated qualification of a commercially available RMM kit to meet Health Canada regulatory requirements.

Methods: We performed an abbreviated qualification using a polymerase chain reaction (PCR)-based Mycoplasma testing method involving assay sensitivity and ruggedness, based on an experimental plan that was pre-approved by Health Canada. Briefly, investigational CTPs were tested in-house using a PCR-based Mycoplasma detection kit. Assay sensitivity was determined using a 10-fold dilution series of genomic DNA of only two Mycoplasma species, Mycoplasma arginini and Mycoplasma hominis in the absence of CTP-matrix as the kit had been previously validated against nine species. Matrix interference was measured by testing independent CTP samples. Testing by different operators on different days measured ruggedness.

Results: The RMM Mycoplasma qualification exceeded sensitivity (4 genome copies per reaction for M. arginini and 0.12 genome copies per reaction for M. hominis) and met ruggedness requirements without matrix interference, as required by the Pharmacopoeial guidelines (Ph. Eur. 2.6.7 and USP <1223>).

Discussion: Our approach represents a minimal qualification that can be performed by an academic institution while ensuring regulatory compliance for implementing RMM testing for in-process and product-release testing of CTPs.

Keywords: cell therapy products (CTPs); mycoplasmas; nucleic acid amplification technique (NAT); pharmacopeia; qualification; rapid microbiological method (RMM).