Accelerating The Regulatory Approval Process Of Biosimilars By Leveraging Precise And Reliable PK Data And PD Biomarker Data

The regulatory approval process for biosimilars is complex and far more demanding than for generic small-molecule drugs. Due to the intricate nature of biologics and the variability inherent in living systems, regulatory agencies require extensive analytical and clinical data to demonstrate biosimilarity in terms of structure, function, purity, and potency. However, according to the FDA’s biosimilar guidance, approval may be based on pharmacokinetic (PK) and pharmacodynamic (PD) similarity studies, potentially avoiding the need for large, costly phase 3 trials.

Relying on PK/PD data offers a more efficient and cost-effective pathway, often involving shorter studies in healthy volunteers. PD biomarkers, which reflect a drug’s effect on its target, are especially valuable. For instance, when a drug targets a receptor involved in complex signaling, changes in protein levels or modifications within that pathway can serve as measurable PD responses. These biomarkers are critical in establishing biosimilarity.

The Biosimilar User Fee Amendments (BsUFA III) further highlight the importance of advancing PD biomarker use through regulatory science initiatives. Common PD biomarkers used in biosimilar development assess receptor engagement, enzyme activity, or downstream signaling changes, depending on the mechanism of action and biological pathways of the reference product.