Debate on Naming of Biosimilars Continues

When the FDA approved a biosimilar of Amgen's biologic drug Neupogen (filgrastim) in March, answering a seemingly simple question posed a decade ago became a priority: Because biosimilars aren't identical to the brand-name drugs they mimic, should they carry the same nonproprietary name?

In a letter sent to the FDA in June, the Biosimilars Council, a division of the Generic Pharmaceutical Association (GPhA), and 18 other groups—including pharmacies and health care organizations—urged the agency to stick with the current international nonproprietary name (INN) system for biosimilars, a class of drugs that will grow as patents expire on biologics. Under that system, administered by the World Health Organization (WHO), the biosimilar would receive the same INN as the biologic drug it imitates.

“Adopting distinguishable names for biosimilars and biologics would erect barriers to patient access to new, more affordable medicines and could jeopardize their safety,” says David Gaugh, RPh, senior vice president of Sciences and Regulatory Affairs at the GPhA. In addition, he says, different names may confuse providers.

However, when Zarxio, a drug that helps prevent infections in patients undergoing chemotherapy, was approved, the FDA assigned it a placeholder name—filgrastim-sndz—until the agency releases a naming policy later this year.

Patient safety and reduced confusion among providers and pharmacists are also cited as arguments in favor of changing the INN system. That's why the Pharmaceutical Research and Manufacturers of America (PhRMA) advocates for a naming system that clearly identifies biologic products. Distinguishable biologic qualifiers, they argue, will improve safety tracking.

“We want to know exactly what patients are receiving,” says Jocelyn Ulrich, MPH, senior director of Science and Regulatory Advocacy at the PhRMA. Distinct names for biosimilars “will help with drug safety and help physicians with decisions regarding treatment choices.”

Under a proposal issued by the WHO in June, a biosimilar and its biologic referent would share a core INN followed by a short series of randomly assigned letters. That scheme, supported by the PhRMA but not by the GPhA, is slated to be discussed at an October WHO meeting. “If WHO does proceed with a biological qualifier, we would prefer that it be the full name of the marketing authorization holder,” says Gaugh.

Although the FDA has jurisdiction over naming in the United States, the agency generally follows WHO recommendations.