Shares of Juno rose $26.71 to $72.31 in premarket trading on Wednesday morning. The Seattle-based company had a market share of about $5.2 billion as of Tuesday.
Celgene is seeking to broaden its portfolio of blood-cancer drugs before Revlimid, its top-selling drug, loses its patent protection, The Journal noted. Juno's approach is focused on developing treatments that use the body's immune system to fight cancer.
The acquisition discussions could result in a deal within weeks, although it's unclear how much Celgene would pay for Juno, The Journal added.