IVDs is defined by a combination of legislation, guidance documents, and regulatory expectations.

• United States: The FDA regulates CDx under the Federal Food, Drug, and Cosmetic Act (FFDCA). They are classified as medical devices, often reviewed through the Pre-Market Approval (PMA) pathway or 510(k) process, depending on the nature of the device. The regulations governing IVDs can be found in 21 CFR Parts 800-899.
• European Union: In the EU, IVDs fall under the In Vitro Diagnostic Regulation (IVDR) (EU) 2017/746, which outlines the requirements for CE marking, clinical evidence, and post-market surveillance. Companion diagnostics that are integral to the efficacy of a drug product are also subject to the Medicines Directive (Directive 2001/83/EC).
• United Kingdom: Post-Brexit, the UK has adopted its own regulations for medical devices, including IVDs and CDx, following the UK MDR 2002 and the In Vitro Diagnostic Regulations 2002 (as amended). Regulatory requirements, including conformity assessment and CE marking transition, are crucial for market access.

Documentation

Effective documentation is essential for navigating the regulatory pathways for CDx and IVDs. The following types of documents are central to the regulatory submission process:

• Product Specifications: Detailed descriptions of the intended use, target population, and analytical and clinical performance characteristics must be provided.
• Performance Studies: Evidence of the clinical validity and utility of the diagnostic test supports its claims. This includes data from clinical trials, laboratory studies, and validation techniques.
• Quality Management System (QMS) Documentation: Compliance with ISO 13485 and other quality standards ensures consistent product quality and supports regulatory submissions.
• Labeling Information: Accurate and comprehensive labeling is critical, covering instructions for use, performance information, and indications specific to each companion therapy.

Review/Approval Flow

Understanding the submission process for companion diagnostics and IVDs is essential for a successful approval strategy. The flow can widely vary between jurisdictions:

United States

The pathway largely depends on the classification of the companion diagnostic:

• PMA Route: For higher-risk devices, applicants must submit a PMA, providing extensive evidence of safety and effectiveness, including data from clinical trials.
• 510(k) Route: Lower-risk devices may qualify for the 510(k) pathway, demonstrating substantial equivalence to a predicate device. The documentation should include data on safety and effectiveness, labeling, and device description.

European Union

In the EU, the process includes:

• Conformity Assessment: Depending on the classification, this may involve self-certification or an assessment by a Notified Body, especially for high-risk devices.
• Clinical Evaluation: A comprehensive review of clinical data against the requirements set forth in the IVDR is mandatory.
• Technical Documentation: Submission of comprehensive technical files to support compliance with the IVDR.

United Kingdom

For the UK, the submission includes:

• Registration with MHRA: Device manufacturers must obtain UKCA marking and submit appropriate documentation to the MHRA.
• Clinical Evidence and Evaluation: A thorough assessment including clinical studies and performance analysis.

Common Deficiencies

Agencies have identified common pitfalls in submissions for companion diagnostics and IVDs, which can lead to delays or denials of authorization:

• Insufficient Clinical Data: Lack of robust clinical evidence supporting the diagnostic’s claims is a frequent point of contention. It is essential to have comprehensive clinical studies that align with agency expectations.
• Inadequate Justification of Performance Characteristics: Failing to provide an adequate rationale for claims made in the submission can lead to requests for additional data or outright rejection.
• Labeling Gaps: Incomplete or unclear labeling can lead to ambiguities that hinder approval. Each claim must be clearly substantiated within the labeling materials.
• Quality Assurance Issues: Non-compliance with QMS requirements can lead to significant regulatory challenges. Ensuring adherence to relevant ISO standards and guidelines is crucial.

RA-Specific Decision Points

In navigating the regulatory landscape for CDx and IVDs, regulatory affairs teams must cautiously consider several key decision points throughout the development and submission process:

When to File as Variation vs. New Application

Determining whether to submit a variation to an existing application or to file a new application is critical:

• Variation: Consider filing a variation if the change primarily affects the product’s labeling, manufacturing processes, or indications that do not fundamentally alter the device safety or effectiveness profile.
• New Application: If the new diagnostic significantly changes performance claims, introduces a novel analytical approach, or aims to target a new patient population, a new application is likely necessary.

Justifying Bridging Data

Bridging data plays a vital role in connecting existing data on a prior submission to a new indication or population. Justification must be detailed and scientifically justified, supported by:

• Strong mechanistic rationale for the connection between the old and new data.
• Preclinical data or expert opinion supporting the applicability of existing evidence.
• Consideration of any limitations of prior data and how new studies will address these gaps.

Conclusion

The regulatory framework surrounding companion diagnostics and IVDs is complex, requiring nuanced understanding and careful execution by regulatory affairs professionals. As these products become increasingly integrated into therapeutic pathways, it is imperative to stay abreast of regulatory changes and agency expectations. By focusing on comprehensive documentation, a clear understanding of the approval process, and anticipation of common deficiencies, pharmaceutical and biotech companies can successfully navigate the regulatory landscape and bring impactful products to market.

For further insights into regulatory expectations and guidelines, consider exploring the FDA’s IVD Regulatory Assistance, the EMA’s guidelines on medicinal products with diagnostic purposes, and the MHRA’s guidance on specialist devices.