How to explain the invalidation of exclusivity?

A patent is a patent granted by the United States Patent and Trademark Office, and the expiration of a patent is the expiration time of a trademark, generally 20 years. The US Food and Drug Administration authorized the exclusive operation. Exclusive expiration is the expiration time of this license, which will be shorter than the patent, usually six months to seven years, depending on the kind of exclusivity:

Orphan medicine (ODE)-7 years

New Chemistry (NCE)- 5 years

"Other" exclusivity-if it meets the standard, it will be "changed" for 3 years.

Pediatric exclusive (PED)-Existing patent/exclusive increased by 6 months

Patent challenge–(PC)–180 days (this exclusive right only applies to ANDAs)