GSK plans to purchase an experimental drug for the liver disease MASH from Boston Pharmaceuticals for $1.2 billion upfront.

GSK will buy efimosfermin, a liver disease drug in late-stage trials, for up to $2 billion from U.S. biotechnology firm Boston Pharmaceuticals, the British drugmaker said on Wednesday. Efimosfermin, a monthly subcutaneous injection,

The new acquisition from Boston Pharmaceuticals adds to a wave of dealmaking undertaken by GSK to build its liver disease franchise.