As a result Neulasta was still Amgen’s second biggest selling drug last year, with the US accounting for nearly $3.9 billion in sales, with only $609 million coming from the rest of the world.

In recent years, Cinfa Biotech used its resources to advance B12019, a biosimilar copy of Amgen’s chemotherapy-induced neutropenia drug Neulasta, through clinical trials. B12019 and Neulasta are ...