Published on 01/12/2025

Bridging Development to PPQ for ATMP

In the complex landscape of Advanced Therapy Medicinal Products (ATMP), the integration of viral clearance validation into Process Performance Qualification (PPQ) is critical. This comprehensive guide outlines the essential steps for pharma professionals in navigating the regulatory maze associated with PPQ, focusing on viral safety, spiking studies, closed systems, and single-use systems, as per the expectations set out by authorities like the FDA, EMA, and MHRA.

Understanding Advanced Therapy Medicinal Products (ATMP)

Advanced Therapy Medicinal Products encompass gene therapies, somatic cell therapies, and tissue-engineered products. These innovative therapeutic modalities carry unique regulatory challenges due to their intricate manufacturing processes and complex quality attributes. Therefore, a profound understanding of both the product and the processes involved in their production is essential for effective validation.

As per the EMA, ATMPs require stringent quality management throughout the product lifecycle, from development through to commercial production. This begins with the characterization of the product and identification of Critical Quality Attributes (CQAs), focusing particularly on potency, identity, and safety.

The implications of these requirements on PPQ planning are profound, as companies must ensure comprehensive validation of processes that align with both regulatory expectations and industry standards such as ICH Q5A(R2) for the safety of biopharmaceutical products.

Best Practices for PPQ and CPV Tailoring in ATMP Production

Process Performance Qualification involves the assessment of a commercial production process to ensure it is robust, reproducible, and compliant with regulatory expectations. The following steps outline best practices for PPQ and Continuous Process Verification (CPV) in the context of ATMPs:

• Step 1: Pre-PPQ Assessments – Conduct thorough assessments of the production process, including risk assessments aligned with ICH Q9. Evaluate raw materials, equipment, and potential sources of variability.
• Step 2: Setting Acceptance Criteria – Establish clear acceptance criteria for CQAs based on historical data, including potency identity and safety parameters.
• Step 3: Process Design and Scale-Up – Ensure that the process design integrates considerations for viral clearance, especially in closed and single-use systems which minimize contamination risks.
• Step 4: Executing Spiking Studies – Perform spiking studies to validate viral clearance methods. These studies should be designed based on risk, employing a range of viral surrogates to assess effectiveness. Utilize well-characterized viruses to provide assurance of the process’s ability to clear potential contaminants.
• Step 5: Documenting and Analyzing Results – Thoroughly document results from spiking studies and assess against defined acceptance criteria. This provides crucial data for regulatory submissions.
• Step 6: Tailoring CPV – Post-qualification, implement a tailored CPV plan focusing on metrics that monitor drift and changes that could impact quality, ensuring adherence to the dynamic nature of ATMP processes.

Ensuring Viral Clearance Validation in Closed and Single-Use Systems

Viral clearance validation is a vital component of ATMP production, particularly in ensuring patient safety through the removal or inactivation of potential viral contaminants. The utilization of closed systems and single-use systems has become increasingly prevalent due to their inherent advantages in reducing contamination and ensuring sterility.

When adopting closed systems or single-use technologies, it is critical to integrate viral clearance validation into each relevant process step. The following approach is advisable:

• Risk Assessment: Perform a comprehensive risk assessment to identify the specific viral risks associated with the input materials.
• Selection of Viral Markers: Choose appropriate viral models for the spiking studies that elucidate the worst-case scenario for viral clearance.
• Process Development and Validation: Develop specific protocols for viral clearance studies that align with FDA and EMA guidelines, ensuring that all studies are robust and reproducible.
• Monitoring and Control: Implement real-time monitoring and control measures during processing to ensure that parameters affecting viral clearance remain within specified limits.

As regulatory bodies emphasize the importance of ensuring safety across ATMP production, the application of stringent viral clearance validation cannot be overstated. Adhering to guidelines as specified in the ICH Q5A(R2) can facilitate a smoother regulatory review process.

Spiking Studies: Methodology and Execution

Spiking studies serve as critical components of viral clearance validation. These studies rigorously assess the ability of processing methodologies to inactivate or remove viral contaminants. The execution of spiking studies involves several crucial steps:

• Selection of Viral Models: Infectious viral agents should be selected based on relevance to the materials and process in question. Commonly used models include Pseudorabies Virus (PRV), Vesicular Stomatitis Virus (VSV), and others that can simulate human viral pathogens.
• Determining Spike Levels: Establish spike levels that reflect worst-case scenarios, considering both low and high prevalence risks to ensure sufficient challenge to the process.
• Process Execution and Sampling: Execute the process using the identified spiking levels and acquire samples at predetermined intervals to measure viral titers at each stage.
• Data Analysis: Analyze the data to determine the log reduction in viral titer, confirming the effectiveness of the process in viral clearance.
• Documentation: Document findings meticulously throughout the process, aligning results with defined acceptance criteria.

Aseptic Controls and Regulatory Compliance: Understanding Annex 1

The implementation of aseptic controls, as detailed in the Annex 1 of the EU Guidelines for Good Manufacturing Practice, is of paramount importance in the manufacture of ATMPs. Annex 1 outlines specific requirements for aseptic processing, ensuring that the products manufactured remain sterile throughout the production lifecycle.

Key elements to consider include:

• Facility Design: Ensure that the manufacturing area is designed to minimize contamination risk, incorporating barriers and air lock systems.
• Personnel Training: Provide comprehensive training for personnel involved in aseptic processing operations, including gowning procedures and techniques to minimize contamination risks.
• Environmental Monitoring: Implement robust environmental monitoring programs to assess airborne and surface contamination, ensuring compliance with specified limits.
• Regular Audits and Inspections: Conduct regular audits to ensure adherence to aseptic controls and facilitate a continuous improvement cycle.

By integrating these controls into the manufacturing process, companies can enhance product quality while meeting regulatory compliance requirements. The guidance provided in Annex 1 serves as a blueprint for establishing a validated aseptic process that ensures the safety and efficacy of ATMPs.

The Importance of Chain of Identity and Custody (COI/COC) in ATMP Production

Chain of identity (COI) and chain of custody (COC) are critical concepts in the manufacture of ATMPs, ensuring that the identity of products and the integrity of materials are maintained throughout the production process. Establishing and maintaining a robust COI/COC is vital in meeting regulatory compliance and safeguarding patient safety.

To properly implement COI/COC practices in ATMP production:

• Traceability: Ensure that all materials used in the production process can be traced back to their origin through properly documented records.
• Material Handling Procedures: Develop procedures that detail how materials are to be handled, stored, and transported to minimize cross-contamination risks.
• Audit Trails: Maintain rigorous audit trails of temperature, storage conditions, and personnel interactions with materials to ensure integrity throughout the process.

Adhering to principles of COI/COC not only bolsters compliance with regulatory expectations but also enhances the overall quality assurance framework of ATMP production, reassuring stakeholders of product integrity throughout the supply chain.

Conclusion: Navigating the Complexities of ATMP Validation

The path from development to Process Performance Qualification for Advanced Therapy Medicinal Products is fraught with challenges, particularly regarding the integration of viral clearance validation and adherence to aseptic processing controls. By following the steps outlined in this guide, pharmaceutical professionals can effectively navigate these complexities while ensuring compliance with regulatory expectations from agencies such as the FDA, EMA, and MHRA.

Through the diligent application of robust validation practices, including diligent spiking studies, thorough risk assessments, and stringent adherence to chain of identity procedures, organizations can assure both the efficacy and safety of ATMPs, paving the way for successful regulatory submissions and ultimately beneficial outcomes for patients.