From Cahan, Kocher, and Bohn in the Health Affairs blog:
Since passage of the 2010 “Biosimilars” Act aimed at stimulating non-inferior innovation and competition in therapeutics markets, only 17 agents have been approved, and only seven have made it to market.
Why haven’t biosimilars been more attractive? Blackstone et al. (2013) cites 3 key issues:
The lack of automatic substitutability, the relatively small price savings, and the reluctance of physicians to use biosimilars
For instance, Teeple et al. (2019)’s survey of rheumatologists, dermatologist and gastroenterologists found that 84% did not want to switch stable patients a biosimilar for cost reasons alone. Similarly, 85% of patients did not want to switch to a biosimilar if they were stable on disease with a branded product.
In short, while payers may be very interested in increased used of biosimilars, physicians and patients are less excited about this prospect.