Context: Amgen’s Blincyto, a drug used for the treatment of refractory acute lymphoblastic leukemia, racked up a total of $1.2 billion in sales across the world in 2024, including over $800 million in the U.S. alone. In January 2022, Amgen’s rival Lindis sued it over Blincyto in the District of Delaware, alleging that the medication infringed three of its patents related to the use of steroid hormones to curb side effects when using a bispecific antibody in a cancer immunotherapy regimen. After a partial dismissal, the complaint was replaced in April 2024 with an amended one, the most important change being that one of the patents was dropped from the case. This happened after the court had construed “lymphoma” to mean “cancer of the lymphatic system” and not to include leukemia. The case then went to a bifurcated trial:
- a jury trial over infringement, validity and damages, which took place in December 2024 and resulted in a $50M+ verdict for Lindis on both remaining patents-in-suit; and
- a two-day bench trial over Amgen’s inequitable conduct defense, which was held in late January.
Amgen also sought a judgment as a matter of law or a new trial, arguing that the jury made an incorrect decision.
What’s new: In an order handed down last Thursday, Judge Gregory B. Williams of the United States District Court for the District of Delaware sided with Amgen, finding that the two remaining patents-in-suit are “unenforceable due to inequitable conduct”.
Direct impact: This new order renders the December jury verdict irrelevant. The companies now have two weeks to reach an agreement or propose suggestions on how the case should proceed.
Wider ramifications: It rarely happens that trial judges overrule juries, but in this case, not all of the issues in the case were put before the jury, and the one issue before the judge himself proved dispositive.
This is the order:
After Lindis first filed suit, Amgen quickly hit back with a motion to dismiss the case in April 2022, arguing against the way Lindis’s legal team defined Blincyto and suggesting that the plaintiff failed to demonstrate how its patents were being infringed. Amgen also emphasized that one of the patents-in-suit specifically concerned the treatment of lymphoma, while Blincyto is specifically used for acute lymphoblastic leukemia.
The original patents-in-suit, all entitled “Combination of the application of antibodies for immunostimulation together with glucocorticoids”, included:
The ‘149 was then dropped in Lindis’s amended complaint (filed in April 2024), which is below. The document is a redline amended complaint, which shows the differences between the original complaint and the amended one:
Lindis noted that in an opinion issued in July 2023, the District of Delaware construed “lymphoma” to have its plain and ordinary meaning, which is “cancer of the lymphatic system”, excluding “leukemia” – partially agreeing with Amgen’s motion to dismiss. Lindis therefore withdrew the third patent, which expressly claimed methods of treating lymphoma.
This is the December jury verdict:
Throughout the case, Amgen has submitted several reply briefs. But the one below is the most important as it was in support of the very argument that got the verdict overturned (inequitable conduct):
In this brief, Amgen’s chief argument was that one of the two inventors of the asserted patents, Dr. Horst Lindhofer (a principal at Lindis), committed inequitable conduct in prosecuting the patents.
The bases of the invention, submitted under oath to the United States Patent and Trademark Office (USPTO), were “surprising finding” and “totally unknown”, which are fully described (with the key parts underlined) below:
- Surprising finding: this novel indication of glucocorticoids in connection with antibody therapy for immunostimulation in the case of diseases, particularly cancer, is based on the surprising finding that the combination of immunostimulating antibodies of defined specificity together with glucocorticoids results in a reduction of the non-specific release of cytokine by immunological cells without the action of the immunostimulating antibodies directed against the defined antigen(s) being impaired.
- Totally unknown: However, in the state of the art and administration of glucocorticoids in connection with the stimulation of the immune system of a patient by antibody therapies, for example with trifunctional antibodies, is totally unknown.
But these premises were then contradicted in an EMA Assessment (a report of the European drug regulatory authority), the Trion Report (a report signed by Dr. Lindhofer), and Huhn (a reference cited in the Trion Report), Amgen argued.
While Dr. Lindhofer knew of this contrary information, he repeated the two premises throughout prosecution as bases for patentability, and the patent examiner relied upon them to allow the claims, Amgen added.
This was not “negligence” or a “mistake” but “affirmative acts of deception”, the drugmaker stated, adding:
“Lindhofer intended to deceive the Patent Office through this pattern of misrepresentation and omission. There is no credible excuse otherwise—Lindis offers only unavailing post-hoc rationalizations. This is inequitable conduct.”
Counsel
Lindis was represented by a team at Saul Ewing LLP led by James D. Taylor Jr., including Jessica M. Jones, Michelle C. Streifthau-Livizos, Henry A. Platt, Robert C. Gill, Alireza Behrooz, Dennis Ostrovsky, Courtland C. Merrill, and Andrew Schwerin.
Meanwhile, Amgen was represented by Young Conaway Stargatt & Taylor LLP’s Melanie K. Sharp, and James L. Higgins, as well as Perkins Coie LLP’s Michael J. Wise, Joseph P. Hamilton, Lara J. Dueppen, Courtney M. Prochnow, Alisha C. Burgin, Doris Alvarez-Reyes, Garmai Gorlorwulu, and Blake A. Winn, O’Melveny & Myers LLP’s Lisa B. Pensabene, Hassen Sayeed, Luann L. Simmons, and Sorin Zaharia, and Autz IP LLC’s Lindsay H. Autz.