Key highlights:

Average approval time reduced by 2.5-3.5 years.

Takeover offers for a company with 2 breakthrough therapy designations increase significantly and quickly.

The key metrics to follow are patient population of the indication, the potential revenue streams, time to approval, possible future indications, and if there is more than one BTD.

Based on historical averages, a pure play company with a BTD for a significant population could be worth $8.3 billion. Companies that meet these criteria should be thoroughly evaluated for their blockbuster (over $1.0 billion in peak sales) potential. 

https://seekingalpha.com/article/4314267-real-value-of-breakthrough-therapy-designation