Priority Review Voucher

What is it and why are they so valuable?

The voucher (started in 2007) entitles the bearer to an FDA regulatory review in about 6 months rather than the standard 10 months. The FDA awards a voucher following approval of a treatment for a neglected disease, rare pediatric disease, or medical treatment.
Two drugs receive priority review for each voucher: 1) the drug winning a voucher for a neglected or rare pediatric disease, and 2) the drug using a voucher for another indication.
The voucher may be sold to another company. For example, a small company might win a voucher for developing a drug for a neglected disease, and then sell the voucher to a large company for use on a commercial disease. The voucher may not be resold again.
There are 3 sources of value from the voucher.
1 - Reaching the market earlier (and the time value of money)
2 - Being on the market for longer (b/c you launch earlier and have the same patent expiration date).
3 - Launching a drug closer to (or before) a competitive drug
Rhythm Pharmaceuticals (RYTM) sold its PRV for $100 million on 5th January 2021, only 2 months after gaining it.
Vifor Pharma said it purchased a PRV, and said on February 18, 2020 the PRV was purchased from Sarepta Therapeutics

Watch this video by Duke University about PRVs