A Delaware federal judge has overturned a $50.3 million jury verdict against Amgen in a patent lawsuit concerning the company’s leukemia treatment Blincyto.
U.S. District Judge Gregory Williams ruled that two patents owned by Lindis Biotech “are unenforceable due to inequitable conduct.” This development nullifies the December jury verdict that found Amgen had willfully infringed Lindis’ immunotherapy patents, a ruling that could have increased the damages award to as much as $150.9 million.
The court has given Amgen and Lindis two weeks to either reach a settlement or submit proposals on how the case should proceed. Neither company had responded to requests for comment at the time of publication.
The dispute began in 2022, when Lindis filed a lawsuit claiming that Blincyto violated three patents related to the use of steroid hormones to reduce side effects during bispecific antibody cancer immunotherapy. Lindis alleged that Amgen had been aware of its patents since 2014, pointing to efforts to challenge similar intellectual property in Europe, and proceeded with infringement regardless.
Amgen responded in April 2022 with a motion to dismiss, disputing Lindis’ definition of Blincyto and asserting that Lindis had not demonstrated infringement of its intellectual property. The company also noted that one of the patents in question, the ’149 patent, pertained to lymphoma treatment, while Blincyto’s FDA approvals are in acute lymphoblastic leukemia (ALL).
In March 2024, Judge Williams granted in part and denied in part Amgen’s dismissal motion, allowing Lindis to amend its claims. Lindis filed an amended complaint, which Amgen challenged again in May. Amgen later argued that the patents were invalid because the named inventor had allegedly provided false information in the patent application.
Blincyto received its first FDA approval for ALL in December 2014 and has since gained additional authorizations in the same indication. The drug recorded $800 million in U.S. sales last year and $1.2 billion globally, representing a 41% increase compared with the prior year—boosting Amgen’s oncology revenue significantly.
In late 2024, Amgen reported phase 3 trial results showing that a combination of Blincyto and chemotherapy helped 96% of newly diagnosed pediatric patients with B-cell acute lymphoblastic leukemia remain alive and disease-free for three years, compared with 87.9% for those who received chemotherapy alone. The study also found a 61% reduction in the risk of disease relapse, remission, or death by secondary malignant neoplasm for the Blincyto group. One of the study’s co-chairs called the results “truly practice-changing.”
The reversal of this verdict against Amgen underscores the impact of judicial findings of inequitable conduct. In this case, the decision means that patents once thought enforceable are now nullified, altering the legal landscape for intellectual property in immunotherapy.
For Amgen, this outcome may reduce potential liabilities associated with Blincyto and reassure investors about risk exposure. It also highlights the importance of how patent applications are drafted, especially involving disclosure obligations. Cases like these may prompt biotech firms to increase diligence in patent prosecution to avoid similar invalidation.
Lindis Biotech now faces strategic decisions: whether to appeal the ruling, renegotiate claims, or adjust legal strategy given the invalidation of significant parts of its case against Amgen. The decision may also influence how companies value patent portfolios in this space.
From a market perspective, Amgen benefits from legal clarity. Blincyto’s solid clinical trial outcomes and its growing global sales are now less likely to be disrupted by this patent dispute. Having this verdict overturned helps stabilize Amgen’s position among competitors and could contribute to continued investment in expanding Blincyto’s use.
On the clinical side, patients and physicians may view this as a positive development: fewer legal clouds over Blincyto can improve confidence in its long-term availability and development. Ongoing and future Blincyto studies are likely to proceed with greater assurance, both in regulatory applications and in funding.
