Biosimilar Interchangeability: ‘Careful What You Wish For’

As the open question around interchangeable biosimilars in the US continues to drive the discussion on what the US Food and Drug Administration (FDA) will require for such a designation, some experts are saying the designation might not actually be that important for the biosimilar market as a whole.

Ronny Gal, senior analyst in specialty pharmaceuticals equity research at Sanford Bernstein, told attendees at GPhA’s first biosimilars conference on Thursday that although interchangeability remains an open question, what’s really driving the development of biosimilars is the economics.

And even when the first interchangeable biosimilar is brought to market in the US (the EU does not have such a designation), Gal warns that there will be a lingering perception (no matter the lengths FDA and others go to to make clear that the interchangeable is no more effective or safe than other biosimilars for the same reference product) that the non-interchangeable biosimilar is somehow inferior to the interchangeable biosimilar.

“If you bring a biosimilar to market, and there’s an interchangeable on the market, it already looks like it’s an inferior product,” he said. “Be careful what you wish for.”

He also noted that the process of informing patients of a switch to either non-interchangeable biosimilars or interchangeable biosimilars will be the same (ie. Patients will see the new biosimilar product and have questions about the differences between the biosimilar and reference product and the switch between them).

Momenta Pharmaceuticals CEO Craig Wheeler said Thursday: “Interchangeability presents opportunities… There’s at least the perception of higher quality, so there is some advantage.”

But Wheeler also noted that the perception is “not as strong as when we first entered this business. These biosimilar programs will be accepted regardless of perception. There are instances where [interchangeables] will be strategically important but it’s not the be all, end all.”

Bert Liang, chair of the Biosimilars Council and CEO of Pfenex, added that interchangeability “has to be achievable,” in terms of the types of studies FDA requires, the return on investment and what patients can afford. If FDA requires four, or even 10 different studies, questions will arise on the return on investment, Liang said. “We have to push for reasonable expectations so if a manufacturer wants to go after it, it’s doable,” he said.

Another open question is what will happen if a biosimilar has already been placed on a formulary and then an interchangeable biosimilar for that same reference product is approved by FDA and comes to market. Will the interchangeable replace the biosimilar on the formulary? And will this perception of inferiority have an impact on whether a biosimilar or an interchangeable biosimilar is placed on a formulary? Or will the biosimilars industry evolve to a point where it's more similar to the generics industry where, as Gal said, "a generic is a generic is a generic"?

While answers to those questions might not be solved until the interchangeable biosimilar market becomes a reality, FDA's draft guidance on interchangeability, which many are saying has already been written and is just awaiting approval, is still on track for release in 2016, Janet Woodcock, director of FDA’s Center for Drug Evaluation and Research, said Wednesday.