Crystal Structures of PF-06438179/GP1111, an Infliximab Biosimilar.

Background: Higher-order structure (HOS) assessment is an important component of biosimilarity evaluations. While established spectroscopic methods are routinely used to characterize structure and evaluate similarity, the addition of X-ray crystallographic analysis to these biophysical methods enables orthogonal elucidation of HOS at higher resolution.

Methods: Crystal structures of the infliximab biosimilar PF-06438179/GP1111 and the reference product Remicade, sourced from US and European Union markets, were determined and compared to evaluate HOS similarity.

The 'totality-of-the-evidence' approach in the development of PF-06438179/GP1111, an infliximab biosimilar, and in support of its use in all indications of the reference product.

The 'totality-of-the-evidence' biosimilarity concept requires that sufficient structural, functional, nonclinical, and clinical data are acquired in a stepwise manner, to demonstrate that no clinically meaningful differences in quality, safety, or efficacy are observed compared with the reference product. We describe the totality of the evidence for PF-06438179/GP1111 (PF-SZ-IFX; IXIFI™ [infliximab-qbtx]/Zessly®) that supported its approval as an infliximab (IFX) biosimilar for all eligible indications of reference IFX (ref-IFX; Remicade®) in Europe and in the US. Analytical similarity involving assays capable of distinguishing structural or functional differences between PF-SZ-IFX and ref-IFX formed a foundation for the biosimilarity exercise.

Infliximab crystal structures reveal insights into self-association.

Aggregation and self-association in protein-based biotherapeutics are critical quality attributes that are tightly controlled by the manufacturing process. Aggregates have the potential to elicit immune reactions, including neutralizing anti-drug antibodies, which can diminish the drug's efficacy upon subsequent dosing. The structural basis of reversible self-association, a form of non-covalent aggregation in the native state, is only beginning to emerge for many biologics and is often unique to a given molecule.

Nonclinical Evaluation of PF-06438179: A Potential Biosimilar to Remicade (Infliximab).

Introduction: PF-06438179, a potential biosimilar to Remicade (infliximab, Janssen Biotech, Inc.), is a chimeric mouse-human monoclonal antibody targeting human tumor necrosis factor alpha (TNF).

Methods: Analytical (small subset reported here) and nonclinical studies compared the structural, functional, and in vivo nonclinical similarity of PF-06438179 with Remicade sourced from the United States (infliximab-US) and/or European Union (infliximab-EU).

Statistical Approaches to Assess Biosimilarity from Analytical Data.

Protein therapeutics have unique critical quality attributes (CQAs) that define their purity, potency, and safety. The analytical methods used to assess CQAs must be able to distinguish clinically meaningful differences in comparator products, and the most important CQAs should be evaluated with the most statistical rigor. High-risk CQA measurements assess the most important attributes that directly impact the clinical mechanism of action or have known implications for safety, while the moderate- to low-risk characteristics may have a lower direct impact and thereby may have a broader range to establish similarity.