Sterility release testing of peripheral blood stem cells for transplantation: impact of culture bottles and incubation temperature

Comprehensive Study Identifies a Sensitive, Low-Risk, Closed-System Model for Detection of Fungal Contaminants in Cell and Gene Therapy Products

The U.S. Food and Drug Administration (FDA) regulates manufacturing and testing of advanced therapeutic medicinal products (ATMPs) to ensure the safety of each product for human use. Gold-standard sterility testing (USP<71>) and alternative blood culture systems have major limitations for the detection of fungal contaminants. In this study, we evaluated the performance of iLYM (lactic acid-fermenting organisms, yeasts, and mold) medium (designed originally for the food and beverage industry) to assess its potential for use in the biopharmaceutical field for ATMP sterility testing. We conducted a parallel evaluation of four different test systems (USP<71>, BacT/Alert, Bactec, and Sabouraud dextrose agar [SDA] culture), three different bottle media formulations (iLYM, iFA Plus, and Myco/F Lytic), and two incubation temperatures (22.5°C and 32.5 to 35°C) using a diverse set of fungi (n = 51) isolated from NIH cleanroom environments and previous product contaminants. Additionally, we evaluated the effect of agitation versus delayed-entry static preincubation on test sensitivity and time to detection (TTD). Overall, delayed entry of bottles onto the BacT/Alert or Bactec instruments (with agitation) did not improve test performance. USP<71> and SDA culture continued to significantly outperform each automated culture condition alone. However, we show, for the first time, that a closed-system, dual-bottle combination of iLYM 22.5°C and iFA Plus 32.5°C can provide high fungal sensitivity, statistically comparable to USP<71>, when tested against a diverse range of environmental fungi. Our study fills a much-needed gap in biopharmaceutical testing and offers a favorable testing algorithm that maximizes bacterial and fungal test sensitivity while minimizing risk of product contamination associated with laboratory handling.

Use of 27G needles improves sensitivity and performance of ATCC anaerobe reference microorganism detection in BacT/Alert system

Effective detection of microbiological contaminations present in medicinal cellular products is a crucial step to ensure patients' safety. In recent decades, several rapid microbiological methods have been developed and validated, but variabilities linked to the use of different resources have led to discordant validation of methods and performance results. Considering this, while developing an in-house BacT/Alert-based method, we evaluated all of the materials used in its validation. Of particular importance, we noticed that the syringe gauge used to inject the samples into the bottles was crucial to obtain robust results. We chose to conduct a comparative test between the BacT/Alert system and the compendial method described in the European Pharmacopoeia, using five dilutions of nine reference microorganism strains and 21G or 27G needles. Our results confirmed that the BacT/Alert system is a valid and faster alternative method to assess sterility of clinical cell therapy products, and that the use of 27G needles increases its sensitivity to detect reference anaerobe microorganisms.

Comparison of CryoMACS Freezing Bags with Maco Biotech Freezing-Ethinyl Vinyl Acetate Bags for Hematopoietic Progenitor Cells Cryopreservation Using a CD34+-Enriched Product

Background: Hematopoietic progenitor cells (HPCs) cryopreservation have applications, especially in the autologous setting, allowing therapeutic use several years after collection. Cryopreservation aims to preserve the therapeutic properties of HPCs, and successful cryopreservation depends on several factors such as preservation procedures, biopreservation media, freezing rates, and thawing procedures. In this context, the choice of the freezing bag is critical as it provides mechanical protection during the freezing process. Since Maco Biotech Freezing-ethinyl vinyl acetate (EVA) Bags^® are no longer available in our country, a comparative study was developed to verify bioequivalence with the Miltenyi CryoMACS^® freezing bag. Methods: In this study, a CD34⁺-enriched product was used to better reproduce HPC apheresis. Freezing bags were filled with the same volume, cryopreserved with controlled rate freezing, and stored in the vapor phase of liquid nitrogen for at least 6 months. After thawing, all bags were tested for integrity and sterility using a microbial challenge. In addition, a comparison was developed by evaluating recovery of white blood cells, mononuclear cells, lymphocytes, and CD34⁺ cells. Results: No significant differences between the two manufacturers' bags have been observed in terms of the evaluated parameters. Data were confirmed, even comparing bags according to filling volume. Data presented in this study support the conclusion that CryoMACS freezing bags are bioequivalent to Maco Biotech Freezing-EVA Bags for HPC cryopreservation.

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.