Amgen's Enbrel fends off biosimilar threat—and heads toward blockbuster superstardom

Gavel court room lawsuit judge
Novartis' generics unit Sandoz said it may appeal its Enbrel patent challenge to the Supreme Court. (Pixabay)

With Amgen’s top line facing pressure for quite some time from biosimilar versions of flagship drugs like Epogen and Neulasta, the prospect that it could lose exclusivity on its top-selling product, anti-inflammatory Enbrel, has been a nagging worry.

So it was no surprise that Wall Street breathed a sigh of relief Wednesday afternoon, after the U.S. Federal Appeals Court upheld a 2019 ruling from the New Jersey District Court that has kept Novartis’ biosimilar rival to Enbrel off the market.

Amgen's victory was another example of its longtime success in fending off patent threats—and puts Enbrel on track to become one of the biggest-selling blockbusters in history, analysts said. Amgen’s shares rose 8% to $255.12 in afternoon trading following the verdict.

Novartis' Sandoz unit, which was on the losing end of the lawsuit with its biosimilar, Erelzi, obviously wasn't so chuffed. Its version was approved by the FDA way back in 2016, but its U.S. launch had been delayed by the ongoing patent dispute.

"Our company respects valid intellectual property, however, Sandoz continues to believe the patents asserted by Amgen are not valid, and that it should not be able to use them to extend the drug’s exclusivity," said Carol Lynch, president of Sandoz US and head of North America, in a statement. The company is considering appealing the ruling to the Supreme Court.

Piper Sandler analysts said the ruling could have gone the other way: "[T]his positive decision for [Amgen] was not a certainty and some discount had been applied” to its shares to reflect the possible hit to Enbrel, which brought in more than $5 billion in sales last year.

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The FDA approved a second biosimilar version of Enbrel in 2019, Eticovo from Samsung Bioepis, but Amgen immediately challenged it with a suit similar to the one it filed against Sandoz.

History suggests that no one should bet against Amgen in that fight, either. Amgen “is really an IP litigation firm that just so happens to be in the business of developing drugs," the Piper Sandler analysts said. "Joking aside, we do think it’s worth stepping back and marveling at [Amgen’s] successes through the years with respect to defending its intellectual property, including this case."

The win against Sandoz extends Enbrel’s patents to the late 2020s, the analysts noted.

Then there’s the ongoing patent fight with Regeneron over PCSK9-blocking cholesterol drugs. Last year, Amgen persuaded a jury to protect its patents on its PCSK9 drug Repatha, and it scored a patent win in Germany, too. That has helped Repatha stay ahead of Regeneron's rival drug Praluent with Amgen’s drug bringing in $661 million in sales last year—up 4% from 2018.

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Meanwhile, Amgen continues to find new ways to preserve Enbrel’s market share. Last December, for example, it signed a deal with pharmacy benefits manager Abarca in which Amgen agreed it would pay a rebate for any patient that stops using the drug after three months.

That was the second outcomes-based deal Amgen formed for Enbrel, which is approved to treat rheumatoid arthritis and five other inflammatory conditions. In 2017, Amgen agreed to a pact with Harvard Pilgrim Healthcare that stipulated it would reimburse less for the drug if patients scored below certain thresholds on compliance, as well as other factors such as the need to take additional drugs to control their pain.

All told, Enbrel could go down in history as one of the best-selling drugs of all time, Evaluate Pharma predicted last year. Evaluate estimated that Enbrel will have brought in $139.8 billion in lifetime sales by 2024. That would place it in the third spot on the list of pharma blockbuster legends, just below AbbVie’s anti-inflammatory Humira and Pfizer’s cholesterol drug Lipitor.