When it comes to a brand’s lifecycle, Zarxio is in its infancy. Less than a month out from the official launch date of Novartis/Sandoz’s Zarxio, the biosimilar version of Amgen’s Neupogen (filgrastim), Amgen’s efforts to protect Neupogen from competition was swatted down by an appellate court. And on September 4, Zarxio, which is used to help increase cancer patients’ white blood count, entered the U.S. market at a 15% discount to Neupogen.
"The launch of Zarxio is a major achievement for Sandoz, which has become the first company to successfully navigate the uncharted territory of the U.S. biosimilars pathway," said Kate Keeping, senior director of biosimilars research at Decision Resources Group (DRG).
Why such a minor discount?
Despite the fact that Zarxio’s approval was greeted enthusiastically by the medical community, particularly oncologists, Zarxio’s 15% discount to Neupogen failed to impress. However, as Keeping explained, "These are just list prices. Sandoz is launching at a moderate discount with the understanding that it will offer rebates and discounts during negotiations."
Even with rebates and discounts factored in, though, the price cut of Zarxio compared with Neupogen pales in comparison to those robust 30% to 50% discounts seen throughout Europe for many biosimilars. But that may be changing, according to Keeping.
"Sandoz is likely to face new competition next year from ApoBiologix, which has two biosimilar applications pending in the U.S.—filgrastim and pegfilgrastim. This will put pressure on Sandoz to expedite its own biosimilar pegfilgrastim and cement Zarxio’s position in the market."
Robust product uptake expected
Nonetheless, right now, Zarxio is the only biosimilar game in town, and it seems that oncologists are receptive. "We expect U.S. oncologists to be comfortable using Zarxio given the biosimilar’s strong track record in Europe and these specialists’ relatively high level of familiarity with biosimilars and Teva’s product, Granix," said Keeping. "Also, U.S. payers tell us they are likely to adopt strategies, such as step edits, to encourage use of the biosimilar ahead of Neupogen."
In addition, Keeping points to the fact that oncologists are likely to be more open to using a biosimilar supportive care product, such as Zarxio, than they would be to using a biosimilar version of Roche's breast cancer star Herceptin (trastuzumab), for example.
Tackling the interchangeability issue
On the downside, there is one major stumbling block for Zarxio in terms of accelerating product uptake. Zarxio has the disadvantage of not being interchangeable. That means that physicians must write the prescription for Zarxio (filgrastim-sndz), and pharmacists cannot automatically substitute Zarxio when the prescription is written for Neuopgen.
Of course, at this point, it would not be possible for Zarxio to be designated interchangeable for the simple reason that the FDA has not defined guidelines for interchangeability. According to Keeping, "The FDA publishes a calendar as to when to expect different types of guidance," explained Keeping. "Interchangeability has been on the calendar for the last two year and we still haven’t seen the guidance."
For now, Sandoz will focus on marketing Zarxio as a biosimilar. The community is receptive, based on the responses of physicians who have attended medical meetings at which Sandoz has presented on Zarxio. All told, the outlook seems positive—at least for the next year.