Zarxio one year on: US biosimilars market still riddled with uncertainty, expert
Sunday marked the year anniversary since Sandoz’s version of Amgen’s Neupogen (filgastrim) made history by becoming the first biosimilar product to be approved by the US Food and Drug Administration (FDA).
The product Zarxio was launched by the Novartis subsidiary in September and remains the sole biosimilar to have received the thumbs up by the Agency.
While a number of other filings have now been submitted through the dedicated 351(k) biosimilars pathway, Kevin Noonan - a partner at Chicago-based McDonnell Boehnen Hulbert & Berghoff LLP - said industry has learnt relatively little as to how the FDA might respond on the back of its actions with Zarxio.
“We can say that the pathway works for biosimilars with a proven track record in Europe and using biologic drugs that have been on the market a long time,” he told Biopharma-Reporter.com, but “we just don’t have the data for other types of biologics yet.”
He added the approval of Zarxio was very unlikely to have opened the approval floodgates from the FDA’s point-of-view.
“The agency has been under tremendous pressure to get a biosimilar to market and has resisted taking shortcuts. Monoclonal antibodies may face longer approval times because they are newer to market as biologics and there is less experience with them elsewhere, or because they are more complicated.”
Celltrion version of J&J’s mAb Remicade – already available in Europe - was recommended by an FDA committee panel last month, and while approval is still not certain, commercialisation partner Pfizer has begun preparing for launch later this year.
Market impact
After four months on the market, Zarxio had helped reduce Amgen’s market share to 76%. Amgen has also faced competition from Teva’s Granix (tbo-filgastrim), approved as a biologic, not a biosimilar, in 2014.
Noonan, an expert in biopharma IP, told us it is too early to tell how Zarxio’s impact has affected the overall biosimilar market in the US.
“Unlike conventional, small molecule drugs biologic drugs have much more physician involvement - they tend to be injectables - and so we can expect some resistance to change just from inertia.
“Also because of this doctor involvement and the lack of an interchangeable pathway adopting any biosimilar will require active involvement from the doctor, which removes any perceived buffer between a bad outcome and the doctor’s responsibility.”
Zarxio’s Discount
As for pricing, Zarxio was launched at a 15% discount to its reference product, and Noonan said such low reductions, along with existing supply agreements, could also stifle biosimilar uptake.
“There will be lower economic pressure because the ‘generic’ discount is much less compelling (15-30%) than it is for traditional generics (80-90%).”
His comments mirror the results of a recent InCrowd survey which found the larger the discount, the more likely a US physician would prescribe the biosimilar rather than an originator biologic.
