Regulatory Considerations in PK ADA Analysis for Drug Development

Immune responses against therapeutic protein can influence drug pharmacokinetics, pharmacodynamics, efficacy, and safety. The effects of unwanted immune responses in patients can vary from detrimental effects to no measurable outcomes. Evaluating anti-drug antibody formation is a vital tool for understanding these potential immune reactions. Additionally, evaluating pharmacokinetic responses concerning ADA formation is crucial for drug development. Today, ADA assay development includes several techniques, such as PK LC-MS systems and PK ELISA assays. 

Information obtained about immune reactions during PK ADA assessment helps researchers evaluate its implications on drug safety, efficacy, and pharmacokinetic/pharmacodynamic properties. Hence, clinical pharmacokinetic services focus on reliable ADA testing along with routine PK assay development. Importantly, immunogenicity data should be included as a subsection in the prescribing information. Similar to biochemical testing, such as cytotoxicity screening, immunogenicity testing requires specific, sensitive, and valid immunoassays for detecting anti-drug antibodies. The current article dives deep into regulatory considerations for PK ADA analysis. 

Regulatory Considerations for Anti-drug Antibody Testing

Risk from unwanted immune responses against biotherapeutic drug products may vary from one product to another. Hence, the FDA recommends employing a risk-based approach to evaluate and manage ADA responses against therapeutic protein. These approaches should adequately detect antigens that can impact physiologically and biologically, such as hypersensitivity or neutralizing activities. 

Researchers use screening assays to detect anti-drug antibodies binding to therapeutic proteins. These tests are followed by confirmatory assays to establish the specificity of anti-drug antibodies against specific therapeutic proteins. The confirmed anti-drug antibodies are characterized further through titration and neutralization assays. Titration assay determines ADA response magnitude as the influence of anti-drug antibodies on drug profile may correlate with the titer of anti-drug antibodies. 

Must Read: Troubleshooting Common Issues in LC-MS/MS Analysis Procedures

Neutralizing antibodies are anti-drug antibodies that can influence the interaction between the drug product and the target. The primary aim of neutralizing antibody assays is to determine the neutralizing capacity of anti-drug antibodies. Additionally, other characterization assays, such as epitope mapping, evaluating cross-reactivity, and isotyping, can also be used. 

The best time to develop anti-drug antibody assays depends on the risk profile of the biotherapeutic protein product. The drug developer must have an immunogenicity risk assessment along with the reason for performing immunogenicity testing while submitting an investigational new drug application. The US FDA recommends conducting immunogenicity testing in phase 1 and 2 studies using screening, confirmatory, and neutralization assays. 

Additionally, samples obtained from clinical studies require fully validated assays. Often, the FDA requests drug developers to develop assays with a fit-to-purpose approach when anti-drug antibodies have a higher clinical relevance before beginning clinical studies. In such cases, sponsors should discuss the timing and reporting of anti-drug antibody testing with the agents. On the other hand, in other circumstances, drug developers may test stored subject samples when appropriate assays are available. However, during license application, sponsors should have data to support full assay validation. 

In conclusion 

PK ADA analysis is crucial for biotherapeutic drug development. Adequate regulatory considerations are necessary to accelerate the discovery and development of biotherapeutic protein products

olsen anderson

5 years experience in business and financial adviser in USA

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button