I think one problem with the CVR is that if CELG takes a majority holding in it, it can force CVR holders to accept their average price. I guess it depends if CELG was buying the CVR at higher prices etc. Need to find the exact wording, but I know there was a backdoor for Celgene.
There is also a payout for revenues
Net Sales Payment: Payment to CVR holders based on Abraxane’s net sales for the year (this extends by default through December 31, 2025, renewable each year until 2030 unless the net sales have not been greater than $1 billion):
2.5% of net sales between $1 and 2 billion
5% of net sales between $2 and 3 billion
10% of revenue > $3 billion