"Doing this transaction clearly indicates that risk to Opdivo in lung cancer is obviously a concern," SunTrust Robinson Humphrey analyst John Boris said in an interview. There is also shareholder concern that drugs in development would not have enough sales to offset major products losing exclusivity between 2022 and 2026. But cash flow from Revlimid buys Bristol-Myers time to pay down debt and position for another transaction, Boris said. Revlimid is expected to record nearly $10 billion in 2018 sales. Celgene shares were up 20.7 percent at $89.43. "Both of them were coming into this year kind of limping," said Brad Loncar, who runs the Loncar Cancer Immunotherapy ETF. The deal makes "the combined entity a lot stronger," he added. Including debt, the deal is worth $95 billion, eclipsing Pfizer's $89 billion purchase of Warner-Lambert in 2000, according to Refinitiv.