<p>Assessment of product immunogenicity in clinical trials via characterization of the anti-drug antibody (ADA) response to the drug, is an important component of biological license applications (BLA). The clinical pharmacology review of immunogenicity focuses on the impact of ADA on pharmacokinetics (PK) based on data from three analysis datasets: Analysis Dataset (AD) for Subject Level data (ADSL), AD for Pharmacokinetic Concentrations (ADPC), and AD for Immunogenicity Specimens (ADIS). These datasets are derived from tabulation datasets that conform with the Clinical Data Interchange Standards Consortium (CDISC) Study Data Tabulation Model (SDTM) as requested by FDA and follow the CDISC Analysis Data Model (ADaM). Because no guidance is available on how to derive the ADIS dataset from the SDTM IS domain, BLAs submitted to the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) vary in the completeness and quality of their ADIS datasets. This challenge has been addressed by information requests that can extend time of the clinical pharmacology review of immunogenicity. We analyzed the availability and content of ADIS, ADPC, and ADSL datasets in 48 BLAs submitted to CDER between 2019 and 2022. 75% of BLAs had at least one type of dataset issue. 50% of all BLAs had data reporting issues specifically (data format issues and/or missing data), 17% had data structure issues (where immunogenicity data were not reported in the dataset where the reviewer expected it, and/or a dataset does not follow the ADaM basic data structure), and 8% had more than one type of dataset issue. Our findings suggest that the publication of clinical trial dataset specifications to support the clinical pharmacology review of immunogenicity data could improve the efficiency of the regulatory review of CDER BLAs.</p> Graphical Abstract <p></p>