Who is pocketing the price difference:

Junshi partnered with California-based Coherus BioSciences to bring the drug to the US, and it is expected to become available within the first quarter of next year.

Gotta love how the US regulatory regime is structured so middle men always get their taste. It's like how the US doesn't produce much in the way of active ingredients, instead US companies import them from China, India, and Poland then package them under their own brand name into pill, capsule, or injectable formulation. During this process the price somehow increases 1,000% to 10,000% over what they paid for the active ingredient.