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

Comparison of Five Commercial Molecular Assays for Mycoplasma Testing of Cellular Therapy Products

Testing of cellular therapy products for Mycoplasma is a regulatory requirement by the United States Food and Drug Administration (FDA) to ensure the sterility and safety of the product prior to release for patient infusion. The risk of Mycoplasma contamination in cell culture is high. Gold standard testing follows USP <63> which requires a 28-day agar and broth cultivation method that is impractical for short shelf-life biologics. Several commercial molecular platforms have been marketed for faster raw material and product release testing; however, little performance data are available in the literature. In this study, we performed a proof-of-principle analysis to evaluate the performance of five commercial molecular assays, including the MycoSEQ Mycoplasma detection kit (Life Technologies), the MycoTOOL Mycoplasma real-time detection kit (Roche), the VenorGEM qOneStep kit (Minerva Biolabs), the ATCC universal Mycoplasma detection kit, and the Biofire Mycoplasma assay (bioMérieux Industry) using 10 cultured Mollicutes spp., with each at four log-fold dilutions (1,000 CFU/mL to 1 CFU/mL) in biological duplicates with three replicates per condition (n = 6) to assess limit of detection (LOD) and repeatability. Additional testing was performed in the presence of tumor infiltrating lymphocytes (TILs). Based on LOD alone, the Biofire Mycoplasma assay was most sensitive followed by the MycoSEQ and MycoTOOL which were comparable. We showed that not all assays were capable of meeting the ≤10 CFU/mL LOD to replace culture-based methods according to European and Japanese pharmacopeia standards. No assay interference was observed when testing in the presence of TILs.

Development of the general chapters of the Chinese Pharmacopoeia 2020 edition: A review

The Chinese Pharmacopoeia 2020 edition was reviewed and approved by the National Medical Products Administration and the National Health Commission of the People's Republic of China in July 2020. The current edition was officially implemented on December 30, 2020. The general chapters of the Chinese Pharmacopoeia discuss the general testing methods and guidelines, which are the common requirements and basis for the implementation of drug standards in the Chinese Pharmacopoeia. Owing to adherence to the principles of scientificity, versatility, operability, and sustainable development, there is an improvement in the general chapters of the 2020 edition over those of the previous editions. Further, the application of advanced and mature analytical techniques has expanded, the development of testing methods for exogenous pollutants in traditional Chinese medicines has been strengthened, and technical requirements are now better harmonized with international standards. The updated edition provides technical and methodological support to ensure safety, effectiveness, and control of pharmaceuticals in China and will play an important and active role in encouraging the application of advanced technologies, improving the quality control of medicines, and strengthening the means of drug regulation in China. This review provides a comprehensive introduction of the main features of and changes to the general chapters in the Chinese Pharmacopoeia 2020 edition and aims to provide reference for its correct understanding and accurate implementation.

In-house abbreviated qualification of a real-time polymerase chain reaction method and strategies to amplify mycoplasma detection in human mesenchymal stromal cells

BACKGROUND AIMS

In this study, the authors performed an in-house abbreviated qualification of a commercially available real-time polymerase chain reaction (PCR) kit for limit of detection (LOD), matrix interference and ruggedness of mycoplasma detection in a human bone marrow-derived mesenchymal stromal cell (MSC(M)) investigational cell product (NCT02351011). The approach used was similar to an abbreviated qualification the authors previously conducted for endpoint PCR, which was accepted by Canadian regulators for final product release of the same MSC(M) investigational cell product for treatment of osteoarthritis patients (NCT02351011). With patient consent, biobanked MSCs(M) were re-analyzed by real-time PCR for mycoplasma detection to conduct in-house qualification of the kit.

METHODS

LOD was determined by spiking MSCs(M) with a series of 10-fold dilutions of two commercially available genomic DNA (gDNA) reference standards for Mycoplasma arginini (M. arginini) and Mycoplasma hominis (M. hominis). Matrix interference was tested by using 10-fold dilutions of MSC(M)s down to 4500 cells/mL. Polyadenylic acid (poly[A]) was used to improve DNA recovery in samples with 4500-45 000 MSCs(M)/mL. Real-time PCR tests performed on different days were compared to evaluate ruggedness.

RESULTS

Real-time PCR analysis showed a conservative LOD of 40 genome copies (GCs)/mL and 240 GCs/mL, which are equivalent to 10 colony-forming units (CFUs)/mL, for M. arginini and M. hominis, respectively. According to a less conservative manufacturer-based criterion for positivity, the kit detected 0.4 GC/mL (0.1 CFU/mL) and 24 GCs/mL (1 CFU/mL) M. arginini and M. hominis, respectively. Real-time PCR with different MSC(M) dilutions did not show matrix interference. However, DNA recovery was compromised at MSC(M) concentrations at or below 45 000 cells/mL. The addition of poly(A) as a DNA carrier improved DNA recovery and allowed an LOD, considered here to be equivalent to 10 CFUs/mL, to be achieved, which was not possible in diluted MSC(M) samples (≤45 000 cells/mL) in the absence of poly(A). Ruggedness was demonstrated with tests (n = 18) performed on different days, with an average overall inter-assay percent coefficient of variation of less than 4 for M. arginini (3.62 [400 GCs/mL], 3.61 [40 GCs/mL]) and less than 3 for M. hominis (2.83 [2400 GCs/mL], 1.95 [240 GCs/mL]).

CONCLUSIONS

A commercially available real-time PCR mycoplasma detection kit was qualified for evaluating mycoplasma contamination in investigational MSC(M) products and met the criteria used previously (and accepted by Canadian regulators) for in-house qualification of an endpoint PCR mycoplasma detection kit, and the addition of poly(A) addressed the poor recovery of mycoplasma gDNA in samples with low cell numbers.

Sterility Testing for Cellular Therapies: What Is the Role of the Clinical Microbiology Laboratory?

Sterility testing of cellular therapy products along with the associated environmental monitoring requirements for aseptic facilities, including compounding pharmacies, continues to impact clinical microbiology laboratories, as evidenced by the numerous discussions recurring on American Society for Microbiology Division C and ClinMicroNet listservs. This minireview provides an overview of this complex field of current good manufacturing practices (cGMP) based on biopharmaceutical industry standards and summarizes the compendial and alternative rapid microbial test methods available for product sterility and Mycoplasma testing. In addition, this minireview highlights major overarching regulatory requirements governing any laboratory performing product testing as regulated by the United States Food and Drug Administration (FDA). These requirements are different from the more familiar clinical requirements of the Clinical Laboratory Improvement Act of 1988 (CLIA '88), the College of American Pathologists (CAP), and the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), all of which have no jurisdiction in this area. As the cellular therapy field continues to advance and an increasing number of medical centers participate in clinical trials of these novel therapies, it is critical that laboratories have a sound understanding of the major regulations and cGMP practices governing microbiological testing in the biopharmaceutical industry.

A Rapid and Sensitive Nucleic Acid Amplification Technique for Mycoplasma Screening of Cell Therapy Products

Mycoplasma species (spp.) bacteria can infect cell cultures, posing a potential threat to recipients of cell therapy products. Conventional Mycoplasma testing methods are highly sensitive but typically require a minimum of 28 days to produce results. This delay is problematic if rapid results are needed to inform treatment decisions. Nucleic acid amplification technique (NAT) methods have been gaining favor for Mycoplasma testing due to their speed and specificity; however, they must first be qualified as meeting or exceeding the sensitivity of the compendial method. We present herein a NAT method for the detection of Mycoplasma that circumvents the need for live Mycoplasma spp. in the test procedure by instead being qualified using Mycoplasma spp. genomic DNA. We have demonstrated a lower limit of detection that exceeds the regulatory requirements set by Health Canada. This assay is now being used to screen clinical cell therapy products manufactured at our center.

Proceedings of the first academic symposium on developing, qualifying and operating a cell and gene therapy manufacturing facility

A significant portion of the more than 1000 candidate cell and gene therapy products currently under clinical investigation (clinicaltrials.gov) are born out of academic research centers affiliated with universities, hospitals and non-profit research institutions. Supporting these efforts are myriad academic clinical materials production facilities with more than 40 such facilities currently operational in the United States alone. In March 2018, Stanford University's Laboratory for Cell and Gene Therapy held a symposium with the leaders and staff of more than 25 similar facilities to discuss the collective experience in developing, qualifying and operating cell and gene therapy manufacturing facilities according to current Good Manufacturing Practices. Topics included facility design, construction, staffing and operations and compliance. Leaders from several institutions gave overviews of the history of development of the facilities and discussed challenges and opportunities they had experienced over the past 10-20 years of operations. Working sessions were also held to discuss specific aspects of Process Development, Manufacturing, Quality Systems, Regulatory Affairs and Business Development with all participants contributing to the discussions. We summarize here the findings of this inaugural meeting with an emphasis on best practices and suggested guidelines for operations.