Everyone with an opinion believes that biosimilar drug use will save the health system considerable money. Calculations for biosimilar savings have been hampered by several factors. For example, previous high estimates have not been based on real-life scenarios. Only 3 biosimilars have been launched and utilized in the US; so little experience has been gained on which to base calculations.

Yet, isolating the savings associated with a single approved biosimilar does put their potential into perspective. It also demonstrates the promise of cumulative biosimilar savings with their launch and uptake. Based on current infliximab average sales prices (ASPs), which considers discounts and rebates, one organization believes that a 50% marketshare for biosimilar infliximab could result in well over $400 million in annual savings system wide.

The analysis, conducted by Wayne H. Winegarden, PhD, Senior Fellow in Business and Economics, Pacific Research Institute, accrued the lion’s share of the annual savings to employer-sponsored health plans ($262 million to $315 million, compared with no sales of infliximab biosimilars). Medicare accounted for up to $150 million savings annually.

Dr. Winegarden tested several scenarios. The calculation considered the cost of the infliximab regimen based its various indications. He calculated biosimilar savings using different add-on percentages to ASP (including the current ASP + 4.3% payment and up to ASP + 20%), as well as different marketshares of the biosimilars (from 10% to 90%).

The current marketshare of the two available infliximab biosimilars—Inflectra^® and Renflexis^®—is below 5%, based on data from the first quarter of this year. This is partly because of Janssen’s tactics in matching the net costs of biosimilars with additional rebates on Remicade. This raises two important points: Dr. Winegarden’s analysis reveals savings accruing to the health care system (not necessarily to the payer). Also, the very existence of infliximab biosimilars has resulted in significant net savings compared with the price increases seen prior to their introduction.

It is a bit more difficult to pinpoint the system savings resulting from the use of the first biosimilar approved in the US, filgrastim-sndz (Zarxio^®). The other branded product, tbo-filgrastim (Granix^®), was launched a couple of years earlier and gained its own marketshare from the reference brand Neupogen^®. No doubt, Zarxio contributed to some level of cost savings. In other words, the infliximab example is an easier calculation with a cleaner result.

With eight biosimilars for six reference products awaiting their turn to hit the market, and drugs like adalimumab and etanercept among them, it is easy to see how biosimilars savings can easily exceed $10 billion. Just not yet.