Communicating Immunogenicity-Associated Risk in Current U.S. FDA Prescription Drug Labeling: A Systematic Evaluation

Communicating the clinical impact of immunogenicity in labeling is important for safe and effective use of certain prescription products. Current U.S. Food and Drug Administration (FDA) guidance does not provide comprehensive recommendations on the communication of clinical impact of immunogenicity in labeling. To understand current labeling practice, we evaluated the immunogenicity data and clinical impact information in labeling of selected prescription products.

We created a database of 71 therapeutic biologics and drug products that had an immunogenicity assessment initially approved by FDA's Center for Drug Evaluation and Research between 2014 and 2018. We analyzed the content and format of immunogenicity information (e.g., anti-drug antibody incidence and/or immunogenicity impact on pharmacokinetics (PK), safety, and/or effectiveness) in the most recent approved labeling.

Immunogenicity information was in the ADVERSE REACTIONS section in 98% of the reviewed labeling. Immunogenicity impact on PK was reported in 52% of the labeling, typically within the ADVERSE REACTIONS section, but supportive PK data were often not included in the CLINICAL PHARMACOLOGY section. Additionally, the immunogenicity impact on safety and/or effectiveness was communicated in 70% of the labeling, with 23% clearly communicating the effect as clinically meaningful, and 10% providing actionable recommendations.

Most of the reviewed labeling includes immunogenicity information within the ADVERSE REACTIONS section. However, there is inconsistency in providing supportive PK data and high variability in reporting immunogenicity impact on safety and effectiveness in labeling. Development of a communication framework that allows for consistent inclusion of immunogenicity impact statements in labeling could improve how immunogenicity risk is conveyed in prescription drug labeling.