FTC tells appeals court Amgen's Enbrel patent-buying can face antitrust scrutiny

The Federal Trade Commission told a federal appeals court this week that Amgen's practice of buying up pending patent applications to keep cheaper rivals off the rheumatoid arthritis drug Enbrel can itself violate antitrust law, even before those applications ever issue as patents.

In a friend-of-the-court brief at the U.S. Court of Appeals for the Fourth Circuit, the FTC backed a lawsuit by CareFirst of Maryland, a health insurer suing Amgen under Section 2 of the Sherman Act. The FTC argues private deals to acquire rights to pending applications should face the same antitrust scrutiny as outright patent purchases, because a monopolist who controls those filings can shape the eventual patent's reach before any patent issues. (FTC)

Enbrel, approved in 1998, treats rheumatoid arthritis. CareFirst alleges Amgen obtained exclusive rights to patent applications it helped shape, then used them to extend its grip on the drug. A federal district court in Virginia declined to dismiss; Amgen appealed.

Amgen argues the deals are immune under Noerr-Pennington, which generally shields parties who petition the government, because it later prosecuted the applications at the U.S. Patent and Trademark Office and enforced the issued patents. The FTC counters that the underlying commercial transaction, the acquisition, remains fair game for antitrust review no matter what comes later.

The Fourth Circuit has not set a date for arguments or a ruling. If the court adopts the FTC's view, generic and biosimilar rivals trying to enter Enbrel could challenge Amgen's patent shield earlier in the lifecycle.