Last month marked the one-year anniversary of the first biosimilar approval in the US. Novartis’ Zarxio, a biosimilar version of Amgen’s cancer drug Neupogen, won approval in March 2015, ushering in a new source of competition for branded biologic drugs in the U.S. Fittingly, the second U.S. biosim, Celltrion and Janssen’s Inflectra, passed regulatory review earlier this month.
However, uptake of Zarxio has been modest over its first year on the market. When the drug launched, Kate Keeping, a senior director of biosimilars research at Decision Resources Group (DRG) predicted uptake would be slower as Zarxio was being launched at only a 15% discount to Neupogen.
But preliminary data shows this might be starting to turn around.
Uptake increased at six months
Although all of the numbers are not in yet, uptake did pick up six months after launch, based on information from a survey DRG fielded several months ago. Initially most practitioners had said that they would not use Zarxio for several months post-launch. However, when DRG checked back, it found that every single oncologist surveyed had prescribed Zarxio to at least one patient six months post-launch.
Keeping noted that although Zarxio is not deeply discounted relative to Neupogen, Novartis has implemented a very robust patient access program for patients who need additional support. In addition, payers have appeared to treat Zarxio similar to Neupogen in terms of coverage and reimbursement.
During the first several months out the gate, physicians were concerned about the fact that Zarxio had been approved using indication extrapolation.
Zarxio, like Neupogen, is approved for all five of Neupogen’s indications—something Novartis stresses on Zarxio’s website—despite the fact it was not independently tested in clinical trials for each indication.
According to the FDA, a biosimilar must be comparable or highly similar to an already-approved biological product and show no clinically meaningful differences in terms of safety and effectiveness in order to gain approval. Zarxio met all of those standards.
Experience in Europe & a strong salesforce
According to Keeping, Novartis has focused its website on trust, reliability and the "totality of evidence” behind Zarxio. The efforts seem to be working as physicians begin to use the biosimilar more often for cancer patients.
However, there is one additional factor working in Zarxio's favor, according to Keeping. "Oncologists in Europe have years of experience with Zarxio, and US oncologists can reference this experience when making treatment decisions," Keeping said.
As Novartis is one of the largest oncology companies in the world, there are also synergies which permit the sales force to easily integrate Zarxio into product portfolios in discussions with oncologists.
Other biosimilar manufacturers will likely look to Novartis’ experience with Zarxio as they attempt to bring a biosimilar to market. Six other biosim applications have been accepted by the FDA and some are set for FDA consideration later this year.