Insulin Glargine (Winthrop) – Unbranded Biologic of Lantus^®

Insulin glargine labeled by Winthrop U.S. came to market in May 2022, and with it a lot of additional confusion regarding pharmacy level substitution.

Keen eyed observers will notice that Winthrop is “a Sanofi company”, and that both Lantus^® and insulin glargine (Winthrop) have the same Biologics Licensing Application (BLA) number BLA021081 – which makes it an “unbranded biologic” of Lantus^®.

Please see a few important notes about unbranded biologics from FDA Purple Book FAQ #9:

1. Unbranded biologics are not separately listed in FDA Purple Book
2. Unbranded biologics are not the same as an interchangeable biosimilar
3. Unbranded biologics are considered by FDA to be equivalent to its brand name biological product because it is the same product as the brand name biological product under the same BLA

Remember that pharmacy level substitution of a reference product is only allowed if biologic drugs are either (i) identified as interchangeable OR (ii) an unbranded biologic with the same BLA number. For biologic drugs that don’t fall into these two categories, you must obtain prescriber approval prior to substituting.

Here is a summary table of how to understand insulin glargine products: