Update (4:06 p.m.): Updated with Monday closing price.
Roche will pay $74 a share, which represents a 38% premium to Friday's closing price of $53.80, in an all-cash deal.
For more on this story, read TheStreet's Adam Feuerstein's article here.
Must Read: Roche Buying InterMune for $8.3 Billion
The stock closed up 35.41% to $72.85. More than 51 million shares, compared to the average volume of 2,075,640.ITMN data by YCharts
EXCLUSIVE OFFER: See inside Jim Cramer's multi-million dollar charitable trust portfolio to see the stocks he and Stephanie Link think could be potentially HUGE winners. Click here to see the holdings for FREE.