An argument based on the FDA’s sharing of purportedly confidential data will be hard to press insofar as Lovenox is no longer protected by a valid US patent, nor is it protected by Hatch-Waxman exclusivity for any indication.
I don't agree with that. Trade secrets are independent of patent and/or H-W.
But I do think their basic argument is specious. Preclinical immunogenicity data can be reviewed independently from Sanofi's data file. And certainly the FDA has the right to review safety as it sees fit. For example, they could review excipients in a generic drug that were different from those used in the original drug.