Genentech and Pfizer urged the FDA in written comments to make its draft guidance on statistical analyses of analytical similarity data for biosimilars more specific and narrower in scope.
Pfizer noted the draft guidance acknowledges challenges and limitations in applying statistical analyses to analytical similarity data, recommending a risk-based approach to such challenges. However, Pfizer wrote, the draft does not make clear how such an approach would address these obstacles. The guidance also fails to address biosimilar developers’ lack of control over the reference product, which may change without warning during biosimilar development, the drugmaker said.
Genentech, meanwhile, said the guidance should be limited to non-orphan drugs and all references to orphan drugs removed, with a possible separate guidance for orphan products.