Biosimilars: The US Regulatory Framework.

With the passage of the Biologics Price Competition and Innovation Act of 2009, the US Food and Drug Administration established an abbreviated pathway for developing and licensing biosimilar and interchangeable biological products. The regulatory framework and the technical requirements of the US biosimilars program involve a stepwise approach that relies heavily on analytical methods to demonstrate through a "totality of the evidence" that a proposed product is biosimilar to its reference product. By integrating analytical, pharmacological, and clinical data, each of which has limitations, a high level of confidence can be reached regarding clinical performance. Although questions and concerns about the biosimilars pathway remain and may slow uptake, a robust scientific program has been put in place. With three biosimilars already licensed and numerous development programs under way, clinicians can expect to see many new biosimilars come onto the US market in the coming decade. [Note added in proof: Since the writing of this article, a fourth biosimilar has been approved.].

Role of Modeling and Simulation in the Development of Novel and Biosimilar Therapeutic Proteins.

Modeling and simulation (M&S) is an important enabler of knowledge integration in novel biological product development programs. Given the volume of data generated from clinical trials and the complexity of pharmacokinetic (PK) and pharmacodynamic (PD) properties for reference products, extending the use of M&S to biosimilar development is logical. Assessing PK and PD similarity is normally a critical part of demonstrating biosimilarity to a reference product. Thoughtful considerations are necessary in study design to minimize the PK and PD variability, thereby increasing the sensitivity for detecting potential differences between products. In addition, the sensitivity of PD biomarkers depends partly on their relevance to the mechanism(s) of action and the dynamic range of PD response(s), including the impact of certain structural differences on PD in the relevant population. As such, opportunities exist for leveraging the available M&S knowledgebase to maximize the efficiency in the design and interpretation of PK and PD similarity studies. This article describes M&S applications which have contributed to and can continue to enhance biosimilar development programs.

Perspectives on the Current State of the Biosimilar Regulatory Pathway in the United States.

The Biologics Price Competition and Innovation Act of 2009 (BPCI Act) created an abbreviated licensure pathway in the United States that allows for the development and approval of biologic products shown to be biosimilar to or interchangeable with a US Food and Drug Administration (FDA)-licensed reference product (Table 1). Here we discuss implementation of the US biosimilar approval pathway and the role of various types of data, including clinical pharmacology data, in biosimilar development.