Published on 29/11/2025

Top Closed System Gaps—and Durable Fixes

Introduction to Closed Systems in Biologics and ATMP Validation

The evolving landscape of biologics and advanced therapy medicinal products (ATMP) necessitates a meticulous approach to validation, especially when dealing with closed systems. Closed systems provide a controlled environment to minimize contamination risks, which is vital in aseptic processing. Given recent regulatory updates, particularly with the revised Aseptic Controls Annex 1 from the European Medicines Agency (EMA), organizations must identify and rectify potential gaps in their closed systems.

This tutorial serves as a practical guide encompassing fundamental aspects such as viral clearance validation, spiking studies, and the importance of potencies and identities of critical quality attributes (CQAs) in developing closed systems and single-use systems. Additionally, we will provide insights into process performance qualification (PPQ) and continued process verification (CPV) tailored specifically for ATMPs.

Step 1: Assessing Current Closed System Designs

A comprehensive assessment of existing closed system designs is essential. This process involves evaluating the integration of single-use systems, identifying potential contamination points, and understanding their interaction with aseptic processing workflows. Various frameworks for assessing closed systems can be used, including:

• Quality Risk Management (QRM): Employing tools and methodologies, such as FMEA (Failure Modes and Effects Analysis), to identify risks associated with closed systems.
• Benchmarking: Comparing existing systems against existing industry standards and best practices can help in identifying performance gaps.
• Regulatory Compliance Checks: Ensure that your designs comply with guidelines set forth by authorities like the FDA and EMA, particularly concerning aseptic technique and quality assurance.

The outcome of this assessment will lay the framework for identifying specific gaps within your closed systems.

Step 2: Implementing Corrective Actions for Identified Gaps

Once gaps in the current systems are identified, it is imperative to devise and implement corrective actions tailored to specific findings. The actions should be categorized based on urgency and impact on product quality and patient safety. Some recommended corrective actions include:

• Redesign of Closed Systems: Integrate robust aseptic controls to mitigate contamination risks identified. This may involve redesigning connections or enhancing the integrity of seals.
• Enhancing Training Programs: Developing comprehensive training sessions for employees on aseptic techniques can decrease human error.
• Regular Maintenance and Monitoring: Establishing a schedule for regular maintenance checks can enhance system reliability. Incorporate real-time monitoring systems to ensure immediate detection of breaches.

Throughout the implementation phase, a document control process must be upheld to ensure all changes are recorded, and training is provided systematically.

Step 3: Viral Clearance Validation and Spiking Studies

Viral clearance validation is an essential aspect of process validation, especially for ATMPs, as these products can be derived from various biological matrices that might carry viral contaminants. The validation process typically involves spiking studies, where known quantities of viruses are introduced to the product stream to assess the efficacy of the viral clearance methods.

Here’s a step-by-step approach for conducting viral clearance validation through spiking studies:

• Define Objectives and Targets: Clearly outline the goals of the viral clearance validation process based on product-specific requirements and regulatory expectations.
• Select Appropriate Viral Models: Choose appropriate viral models relevant to the product type, ensuring they represent worst-case scenarios.
• Design the Study: Plan the spiking studies methodically, detailing concentration levels, timing, and methods of detection.
• Conduct Studies: Execute the spiking studies rigorously, following strict aseptic techniques, and collect data systematically.
• Analyze Data: Evaluate the results against predefined viral clearance acceptance criteria. Ensure comprehensive documentation is maintained throughout.

Successfully demonstrating viral clearance through validated methods confirms compliance with ICH Q5A(R2) guidelines, instilling confidence in product safety and efficacy.

Step 4: Managing Critical Quality Attributes (CQAs)

The identification and management of critical quality attributes (CQAs) are paramount to ensuring product quality and safety, especially in closed systems. Potency and identity CQAs must be determined to provide a baseline for the biological activity and composition of the final product. These parameters should be continuously monitored throughout the production process and validated through:

• Risk Assessment: Perform a risk assessment to identify which CQAs most significantly impact the product’s quality and patient safety.
• Analytical Method Development: Develop robust analytical methods that can accurately measure potency and identity throughout production runs.
• Routine Monitoring: Integrate routine monitoring of CQAs into the overall process to promptly identify any variance that could signal a potential quality issue.

The alignment of CQAs with the established acceptance criteria fortifies the assurances of product integrity and regulatory compliance.

Step 5: Establishing a Robust Chain of Identity Custody

Maintaining a strict chain of identity (COI) custody throughout the manufacturing process is vital. This involves documenting every transfer or processing step an ATMP undergoes to ensure traceability and accountability. Here are the critical components to successfully manage the COI:

• Documentation of Each Step: Implement detailed documentation practices that record all handling stages, ensuring thorough tracking of materials and their corresponding identities.
• Electronic Tracking Systems: Employ electronic tracking systems for real-time data entry, enhancing transparency and aiding in audits and inspections.
• Audit Trails: Maintain comprehensive audit trails to support compliance with regulatory demands. This should include timestamps, user codes, and any changes made to batches.

Maintaining a strong COI ensures product integrity and ease of regulatory review, thus fostering stakeholder confidence.

Step 6: Tailoring PPQ and CPV for ATMPs

The Performance Qualification (PPQ) and Continued Process Verification (CPV) processes must be tailored specifically to the complexities of ATMPs. These steps ensure that manufacturing systems operate within defined parameters throughout the lifecycle of the product. The process includes:

• Initial Performance Qualification: Design a robust PPQ strategy that evaluates multiple batches produced under varying conditions, ensuring the system can consistently deliver quality products.
• Process Control Strategies: Establish control strategies that link parameters and critical control points with CQAs. Continual refinement can be employed based on historical data analysis.
• Ongoing Verification: Implement status checks and routine reviews to monitor process control, identifying areas for improvement or adjustments based on data insights.

This process builds a strong foundation for ongoing assurance of product quality and aligns with both FDA process validation requirements and best practices established in the guidance from regulatory bodies.

Conclusion

The optimization of closed systems in the manufacturing and validation of biologics and ATMPs involves a detailed examination of processes, adherence to regulatory guidelines, and an unwavering commitment to quality assurance. Through the steps outlined in this tutorial, professionals can effectively identify gaps within their systems and implement durable fixes that enhance product safety and efficacy. Continuous vigilance and proactive strategies will help align operations with guidelines set forth by agencies such as the EMA and WHO, ensuring sustainable compliance in an ever-evolving regulatory landscape.