Amgen Takes Its Enbrel Fight to Novartis as Patent Trial Begins

Amgen Inc.’s blockbuster arthritis drug Enbrel already has competition from copycat drugs in Europe. But the company is still fighting to retain its dominance in the U.S. and keep a version of the drug by Novartis AG’s Sandoz unit off the market.

In a federal trial that begins Sept. 11 in Newark, N.J., Novartis is challenging five patents related to Enbrel. If Novartis is successful, its copycat Erelzi could enter the U.S. market, likely eroding sales of Amgen’s biggest drug.

Enbrel had U.S. sales of $5.2 billion in 2017, 23 percent of Amgen’s revenue, according to data compiled by Bloomberg. In the first six months of 2018, Enbrel had sales of $2.3 billion, down from $2.5 billion during the same period in 2017, Amgen said July 27 in its quarterly earnings report.

Enbrel blocks the action of tumor necrosis factor, or TNF, a protein that regulates immune cells. When the body produces too much TNF, it can cause the immune system to attack healthy tissue and lead to inflammation.

Unlike a generic drug, which directly copies the recipe from the brand-name drug, biosimilar drugs are based on a living organism and require more testing and advanced manufacturing skills. A biosimilar piggybacks on some of the safety and efficacy tests of the drug that it’s copying, so it costs less to develop. The U.S. Food and Drug Administration approved Erelzi in August 2016, but Sandoz has agreed not to launch until an undisclosed date.

Five Enbrel patents are at issue in the trial that starts Sept. 11. Three are patents that cover ways to block the TNF; they expire next year, according to Bloomberg Intelligence. Two of the patents, which cover the drug’s active protein, etanercept, and a process to make the drug, could protect Amgen’s flagship drug until their expirations in November 2028 and April 2029.

If the two patents survive the court’s scrutiny, the Thousand Oaks, Calif.-based Amgen could keep Enbrel free from biosimilar competition in the U.S. for another 10 years. Sandoz, for its part, is claiming the patents are invalid. The original Enbrel patent expired in 2012.

A glance at the European landscape shows what Amgen is likely to face in the U.S. when biosimilars invade Enbrel’s territory.

Pfizer Inc. holds exclusive rights to Enbrel outside North America. In the first half of this year, Enbrel sales in Europe dropped by 12 percent, to $1.06 billion from $1.21 billion during the same period in 2017, Pfizer said Aug. 9 in its quarterly earnings report. Sales are expected to plunge even further because of the biosimilar competition, according to analysts’ estimates compiled by Bloomberg.

Amgen’s 20-year-old best-seller, whose approved treatments include rheumatoid arthritis and plaque psoriasis, also faces strong competition from drugs such as AbbVie Inc.’s Humira.

Novartis last week announced it had agreed to sell portions of its Sandoz U.S. portfolio to focus on “complex generics, value-added medicines and biosimilars.“

The case is Immunex Corp. v. Sandoz Inc., D.N.J., 2:16-cv-1118, trial begins 9/11/18.

—With assistance from Kristen V. Brown, Jacquie Lee and Laurie Asséo.

©2018 Bloomberg L.P. All rights reserved. Used with permission

To contact the reporters on this story: Christopher Yasiejko in Wilmington, Delaware, at; Susan Decker in Washington at

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