The FDA has approved Rezvoglar, the second interchangeable biosimilar for Lantus (insulin glargine); the first was Semglee.
What is a biosimilar? It’s kind of like a generic drug, but in the case of biologics, it has to be highly similar and have no clinically-meaningful differences.
https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/761215s000Orig2s000.lbl.pdf
@rchusid That is an excellent question.
For generics, the more there are, the more the price is driven down.
From the FDA, looking at average manufacturer prices reported to CMS:
1 generic: 39% lower than the brand name drug
2 generics: 54% lower
4 generics: 79% lower
6+ generics: 95+% lower
Source: https://www.fda.gov/media/133509/download
I imagine (and hope!) that this would be the same for biosimilars.
Monica Di, PhD 
Ron Chusid