Getting a drug to market is horrifically risky all the way up through approval (and still somewhat risky post approval). ~1/1000 compounds get to market and ~1

Getting a drug to market is horrifically risky all the way up through approval (and still somewhat risky post approval). ~1/1000 compounds get to market and ~1/100 drugs make it from Phase 1 (first in human/safety) to sale. By the time the odds are decent that a drug will get approved, the sponsoring company will have sunk much of the ~$1 billion it takes to get all the way across the line. At that point the valuation of said startup is going to be approaching the expected life time value of the drug (less a discount for risk of a late failure and the time value of money). Any acquirer might as well finishing getting the drug and its new patent protection the rest of the way to market.