Merck, the New Jersey-based drug giant, is spending $1 billion on a new Delaware factory to bring production of its best-selling cancer drug Keytruda to the U.S. and speed future drugs to market. Keytruda is currently made in Ireland and by contract manufacturers in the United States.

Merck is investing $1 billion to build a U.S. plant in Delaware, in a show of its commitment to domestic manufacturing.