It's... complicated but I assume the GP meant new drug product exclusivity [1] which is a process by which a pharmaceutical manufacturer can get a short window of exclusivity for a new approved use without rights over the original patent. That exclusivity is largely for generic manufacturers [2] though and it's separate from the patent patent term restoration [3] the FDA grants to patent holders to help with the time it takes to get to market.

"Re-patent" would mean something different like Shire patenting Vyvanse by adding an amino acid cap to amphetamines, changing it enough that it becomes a new drug with a new patent. That would require clinical trials and all the expense that goes with them.

[1] https://www.fda.gov/drugs/cder-small-business-industry-assis...

[2] https://www.fda.gov/drugs/development-approval-process-drugs...

[3] https://www.fda.gov/drugs/cder-small-business-industry-assis...