Merck & Co Inc said on Thursday it would buy drug developer Pandion Therapeutics Inc for about $1.85 billion in cash, expanding its portfolio of drugs that target autoimmune diseases.
The $60-per-share deal represents about 134% premium to Pandion's closing price on Wednesday.
Shares of Pandion rose 131.6% to a record high of $59.37 before the bell, while Merck shares were up about 1%.
Pandion's lead drug candidate, PT101, met its main goals of safety and tolerability last month in an early-stage trial in patients with autoimmune diseases.
In November, Merck agreed to buy privately-held VelosBio for $2.75 billion to