61% of respondents to a survey of physicians who prescribe biologics and biosimilars in Europe believe that if two products share an international nonproprietary name, they are approved for all of the same indications. But “this is not necessarily the case, and a misunderstanding can be potentially dangerous,” the US Food and Drug Administration has been told.

The concern is expressed in a letter sent to FDA Commissioner Margaret Hamburg by a group of 11 medical associations and 23 individual prescribers, as the agency begins its evaluation of the first US application for approval of a biosimilar – a version of Amgen’s Neupogen (filgrastim). They tell her that follow-on products must have nternational non-proprietary names (INN) that are distinguishable ifrom their reference products because this will help alert physicians that each product, while safe and effective, may cause different reactions among patients with the same diagnoses and similar physical characteristics.

Also, distinguishable names will help prevent inappropriate pooling of adverse events by clearly identifying which product a patient was prescribed, says the letter, which urges the Commissioner that the naming issue is “critical.”

In contrast, last month Commissioner Hamburg received a letter from groups representing pharmacy, labour unions, health insurance plans and others, telling her that requiring different INNs for the original biologic and a biosimilar could lead to patient and prescriber confusion, increasing the possibility of medication errors and slowing the uptake of biosimilars.  “It would also effectively separate the biosimilar from existing safety information about the underlying molecule,” they said.

Cost is often a barrier to patient compliance with their drug regimens, and while biologic medicines are often the only lifesaving treatments for the most severe diseases, their high price tags – at around 22 times greater than for a traditional drug – can keep them out of reach for many patients. But estimates from various economic impact studies predict savings of $42-$108 billion over the first 10 years of biosimilar market formation, the pharmacy and other groups wrote.

Also, a survey of members of the seniors’ organisation RetireSafe finds that 92% did not know that the Affordable Care Act potentially allows for a biosimilar to be substituted for a biologic drug, and that, again potentially, this could be done without the knowledge of the patient or the doctor.

90% of the RetireSafe respondents said the names of the original biologic and the biosimilar should be different, to allow for adequate tracking of any adverse reactions. Also, 91% believed that physicians should be notified of any substitution of the original biologic which they had prescribed for their patient, and 94% said that patients should also be notified.