Spear Pharma sent a citizen’s petition to the FDA, requesting that the agency maintain bioequivalence requirements for abbreviated new drug applications that cite Spear’s product Efudex (fluorouracil) as a reference listed drug and seek regulatory approval of a topical generic drug product.

The firm stated that 5-flourouracil is a cytotoxic drug that can have severe side effects with overexposure, arguing that a clinical trial is the only safe way to test the bioequivalence of a generic Efudex product and assure its side effects and severity are no worse than those of the reference drug.

It also said its product should not be a priority for alternative bioequivalence pathways because three generic versions of Efudex are already on the market.