a biosimilar product declared interchangeable—that is, so close it can be swapped for the original product in hospitals and pharmacies without a doctor’s specific say-so. (The first declared interchangeable with an original product also gets a short but exclusive period to tout that advantage.)
But the bar for interchangeability, according to FDA guidelines, will be even higher. How high isn’t clear. The FDA has yet to solidify those guidelines into rules; a new draft of those guidelines is due sometime this year. In the words of McKinsey’s Goeller, companies don’t know yet “how similar is similar enough,” or what they need to do to get there. (Novartis’s Zarxio was approved as a biosimilar, not an interchangeable, based on a battery of data that included five years of the product’s use in Europe, where it was approved in 2009.)
Biosimilar developers acknowledge they are in a higher-cost business than traditional generics, but the price tag of large clinical trials, if FDA deems them necessary in certain cases, might be too much to swallow. The calculations could be complex. How much evidence will FDA require before granting market access, and how much will the agency be willing accept from post-marketing, real-world use?
The FDA is also trying to figure out what to call biosimilars. Recall the name of the first U.S. biosimilar: filgrastim-sndz, a.k.a. Zarxio. The “sndz” suffix is short for “Sandoz,” the generics unit of Novartis making the product. That’s a placeholder for now, while the agency gathers input on a proposal it floated a few weeks ago to give each biosimilar version of a drug (and perhaps even the original molecule itself) a new four-letter suffix while still allowing the fanciful “brand” names, like Zarxio, that often inspire a good laugh.
Branding might seem like a side issue, but as Bioworld noted in the wake of the proposal, the discussion already seems to have underscored an important point: Each biosimilar is not just different from the original product, but also different from one another. Similar, but different: That might be a confusing message to overcome in the next few years.
