Therapeutic Protein Testing Guidance Comments

Novartis says that a revised draft FDA guidance on assay development and validation for immunogenicity testing of therapeutic protein products largely focuses on developing and validating neutralizing antibody assays. “However,” it said in a comment letter, “an integrated assessment of immunogenicity, pharmacokinetics, and pharmacodynamics may be more appropriate since the neutralizing antibodies assays are based on artificial systems that typically have little in common with the in vivo situation. This is true for both cell-based and competitive ligand binding assays.” The company submitted other general and specific comments on the draft.

In its letter, Boehringer Ingelheim said it agrees that the revised draft’s organization provides greater clarity in comparison to the initial 2009 draft, and the added information on titering and confirmatory assays is helpful. The company also provided specific comments.

Line-by-line comments were submitted by AstraZeneca and Biogen.