The US Food and Drug Administration has released a draft guideline detailing what drug companies must do to obtain “interchangeability” designation for their lower-cost biosimilars referencing biologic drugs.

The draft guidance, announced on Jan. 17, presents a clearer, albeit stringent, roadmap for drugmakers seeking to challenge sales of the world’s topselling biologics whose patents have expired, with cheaper alternative biosimilar drugs.

For a biosimilar to be judged “interchangeable” with its reference drug, companies should prove through “switching studies” that a biosimilar produces the same clincial results as the original drug in any patient, and that switching to a biosimilar is safe, according to the FDA.


These studies must include two or more alternating exposure periods for each of the biosimilar and the original drug, it explained.

The FDA has 60 days to review the draft guidance and announce finalized guidelines.

The proposed guidelines present an important step for the US drug regulator’s efforts to streamline and clarify its regulatory framework for biosimilars.

Currently, the FDA approves biosimilars able to demonstrate a high level of similarity to the originator drug in terms of efficacy and safety.

However, the US drug regulator had not specified what steps biosimilar makers should take to win “interchangeability” status -- a designation that would expand the cheaper drugs’ prescription range in the US market.

South Korea’s Celltrion, which released the first biosimilar referencing Remicade (infliximab) in the US through its partner Pfizer last November, said it views the FDA’s new guidelines in a “positive light.”

“Once the US FDA releases its finalized guidelines, we plan to take appropriate measures (to obtain interchangeability status for Remsima),”  said a Celltrion spokesperson.

Remsima, also known as Inflectra in the US, is a biosimilar referencing Johnson & Johnson’s autoimmune disease treatment Remicade.

Meritz Securities analyst Lee Tae-young noted in a Thursday report that Celltrion’s Remsima could be challenged in the US if latecomer Remicade biosimilars secure interchangeability status.

However, Lee stated that Remsima’s position in the US would remain solid for the time being, as there are no known Remicade-referencing biosimilars in the making that have secured the type of clinical data required by the FDA for interchangeability.

Celltrion further noted that it is already ahead of rivals preparing such clinical datasets, on top of being the first and only seller of a Remicade biosimilar in the US.

Last Octobr, the Korean drugmaker executed a switching study sponsored by the Norwegian government called “Nor-Switch,” which found Celltrion’s Remsima was not inferior to its reference product Remicade.

“As a ‘first mover,’ Celltrion has accumulated rich clinical data proving the effectiveness and safety of Remsima. And we doubt that other firms can match the extent of our clinical data pool,” a Celltrion spokesperson said.

By Sohn Ji-young (jys@heraldcorp.com)