Science has advanced enough that biosimilar sponsors can make a strong case for their product’s similarities to a reference product, but it’s going to be “critical” that sponsors understand the limits of their analytics, the FDA says in a new draft guidance.
“Despite improvements in analytical techniques, current analytical methodology may not be able to detect or characterize all relevant structural and functional differences between the proteins products,” the agency says in the 31-page draft guidance. “A thorough understanding of each analytical method’s limitations will be critical to a sponsor’s successful identification of residual uncertainties and, in turn, to the design of subsequent testing.”
The agency’s hope is that biosimilar sponsors will prepare comparative analytical data “early in product development” which will, in turn, “permit more detailed discussions with” regulators “because known quality attributes can be used to shape biosimilar development.”
When putting together their comprehensive analyses, the agency says, sponsors should consider nine factors: how a given protein is expressed in the body, how it’s manufactured, its physicochemical properties, its functional activities, how it binds to other proteins, potential impurities, the properties of the reference product and its standards, the finished drug product and the protein’s stability.