9. Neulasta

Neulasta faced its first biosimilar, Mylan's Fulphila, last summer, and by year's end, the original brand's sales were on the decline. (Amgen)

9. Neulasta
2018 U.S. sales: $3.9 billion
Used for: low white blood cell count

With two Neulasta biosimilars receiving FDA approval within six months of each other, Amgen has reason to worry about its white blood cell booster’s future. If 2018 was any indication, those worries are well founded.

The brand cleared $3.9 billion in U.S. sales last year, a 2% drop from the previous year and a sign of the challenges the drug will face moving ahead.

In June 2018, Mylan received FDA approval for its Neulasta biosimilar, Fulphila, ending Neulasta’s exclusive grip on the market for white blood cell boosters for cancer patients after chemotherapy.

And despite two Amgen lawsuits alleging manufacturing patent infringements by Mylan, the copycat maker chose to go ahead and launch its biosimilar, which analysts said was a good move given the “weak” patent protection.

Having just one challenger in the market presented immediate problems for Neulasta's bottom line, with the drug performing poorly in the fourth quarter of 2018. In that quarter, Neulasta posted $897 million in U.S. sales, compared to $977 million the previous year. 

But 2019 has brought even more competition. Late last year, drugmaker Coherus followed up with an FDA approval for its own Neulasta biosimilar, Udenyca. Coherus launched its drug in January 2019 with a 33% payer discount off Neulasta’s list price, at $4,175.

9. Neulasta