by Amanda Conschafter, blog editor
On Friday the Food and Drug Administration approved the United States’ first biosimilar medicine. Zarxio, biosimilar to Neuopgen, protects cancer patients from infection by boosting their white blood cell production. Experts and news outlets already are heralding the drug’s cost savings. Express Scripts estimated $5.7 billion over 10 years, while Avalere Health projected biosimilars in aggregate saving $47 billion over the same time period. Zarxio’s manufacturer refuses to comment on the drug’s price pre-market. But if estimates prove accurate, lower prices could allow patients to access powerful cell-derived medicines more easily.
Yet questions of vital safety protections remain. The FDA assigned Zarxio an international nonproprietary name that’s distinct from the brand-name biologic’s. The INN consists of the active ingredient’s name followed by a suffix denoting the drug’s manufacturer. But the FDA is quick to qualify the name as a “placeholder,” which “should not be viewed as reflective of the agency’s decision on a comprehensive naming policy.”
The FDA also determined that Zarxio is not interchangeable with its biologic predecessor. According to the biosimilar pathway created by the Affordable Care Act, pharmacists can dispense biosimilars for prescribed biologics only if the FDA deems the biosimilar interchangeable. Several state legislatures currently have bills clarifying whether pharmacists must notify physicians when substitutions occur. But for now, cancer patients taking the brand-name biologic don’t have to worry about their prescription being filled with Zarxio without their knowledge.
This biosimilar also leaves the contested issue of indication extrapolation open for continued debate. The FDA did extrapolate indications for Zarxio, approving it for uses for which it had not been thoroughly tested. The drug’s years of use in Europe, however, support its safety and effectiveness in much the same way that traditional clinical testing would have. Future biosimilars may not have the same real-world proof of safety and efficacy. Thus, indication extrapolation for these drugs could pose a much higher risk.
But for now, patients, pharmacists and health care providers prepare for Zarxio to become commercially available. And the FDA moves forward with considering still more applications for new, potentially lower-cost biosimilars.