Guardant Health, Inc. v. Tempus AI, Inc.

CourtDistrict Court, D. Delaware
DecidedFebruary 20, 2026
Docket1:25-cv-00082
StatusUnknown

This text of Guardant Health, Inc. v. Tempus AI, Inc. (Guardant Health, Inc. v. Tempus AI, Inc.) is published on Counsel Stack Legal Research, covering District Court, D. Delaware primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Guardant Health, Inc. v. Tempus AI, Inc., (D. Del. 2026).

Opinion

IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE

GUARDANT HEALTH, INC., Plaintiff and Counterclaim-Defendant, V. Civil Action No. 25-82-GBW TEMPUS AI, INC., Defendant and Counterclaim-Plaintiff.

David E. Moore, Bindu A. Palapura, POTTER ANDERSON & CORROON LLP, Wilmington, DE; Jennifer L. Keller, Chase Scolnick, Gregory Bernstein, Gregory M. Sergi, Akhil Sheth, KELLER ANDERLE SCOLNICK, Irvine, CA. Counsel for Plaintiff / Counterclaim-Defendant Pilar G. Kraman, Jennifer P. Siew, YOUNG CONAWAY STARGATT & TAYLOR, LLP, Wilmington, DE; Sean Gallagher, Brain Swanson, Anastasiya Maione, Lee Mason, Grace Kavinsky, BARTLIT BECK LLP, Chicago, IL. Counsel for Defendant / Counterclaim-Plaintiff

MEMORANDUM OPINION February 20, 2026 Wilmington, Delaware

~ GREGORY B. WILLIAMS UNITED STATES DISTRICT JUDGE Pending before the Court is Defendant and Counterclaim-Plaintiff Tempus AI, Inc.’s (“Tempus”) Motion for Preliminary Injunction against Plaintiff and Counterclaim-Defendant Guardant Health Inc. (“Guardant’’) (D.I. 61), which is fully briefed (D.I. 62; D.I. 82; D.I. 98; D.I. 110). For the reasons stated below, the Court denies Tempus’s Motion for Preliminary Injunction (the “Motion”’) (D.I. 61). I. BACKGROUND Guardant and Tempus sell liquid and tissue biopsy tests that provide information about the molecular profile of a patient’s cancer. D.I. 64 § 3. Doctors use these biopsy tests to create treatment plans. /d.! Liquid biopsy tests use a patient’s blood to analyze circulating tumor DNA (“ctDNA”) shed from a tumor that flows through the bloodstream. Jd. § 5. Tissue biopsy tests analyze tissue taken from a cancerous tumor. /d. Depending on various factors, physicians may choose to order one test, or both tests, to determine a patient’s appropriate course of treatment. /d. For example, if a test identifies that certain mutations are present, the patient may qualify for certain treatments and may forgo other treatments, such as chemotherapy. Jd. 4. Guardant offers Guardant360 Tissue, a tissue-based test, as well as Guardant360 Liquid and Guardant360 CDx, which are both liquid-based tests. Jd. § 7. Tempus offers tissue-based tests called xR and xT, along with liquid-based tests called xF and xF+. /d.

' Jonathan Freaney (“Mr. Freaney”) is a Vice President of Research & Development Strategy & Operations at Tempus, who submitted his declaration in support of Tempus’s Motion for Preliminary Injunction. D.I. 64 4 1-2.

In December 2024, Guardant distributed an advertisement” that compared Guardant360 Liquid to Tempus xF+. D.I. 62 at 6. The advertisement states that Guardant360 is “the most sensitive liquid biopsy available,” and compares various specifications between Guardant360 and Tempus xF+. D.I. 63-1, Exs. C-E. Tempus claims that, during the course of discovery, it became aware of additional advertisements making similar or identical claims. D.I. 62 at 6; see also D.I. 63-1, Exs. H—J (collectively, “Guardant’s Liquid Ads”). Guardant also disseminated advertisements that compared Guardant’s tissue test, Guardant360 Tissue, to Tempus’s tissue tests, xT and xR (“Guardant’s Tissue Ads”). D-I. 62 at 8; see also D.I. 63-1, Exs. M-O. These advertisements claim that Guardant’s tests require physicians to submit “40% fewer slides” than Tempus’s tests (or the industry standard), and “[w]ith the lowest sample requirement, more patients get results.” D.I. 63-1, Ex. M at 512. One of Guardant’s Tissue Ads reports that Guardant can get answers when other competitors cannot, and that more samples can be evaluated. D.I. 62 at 9; see also D.I. 63-1, Ex. N. In addition to Guardant’s Tissue Ads and Liquid Ads, Guardant sales representatives sent advertisements to customers in the form of newsletters and emails. D.I. 62 at 9. Specifically, one newsletter states that “another liquid biopsy missed . . . mutations in their advanced breast patients and . . . mutations in their metastatic lung patients.” D.J. 63-1, Ex. L. Additionally, the advertisement suggests that patients will have more “sunny days with their loved ones” when using Guardant360 Liquid. Jd. Guardant brought this lawsuit against Tempus seeking declaratory relief that (1) its advertising for Guardant360 is not false or misleading and (2) its advertising comparing

* In its Motion, Tempus separates a single ad into separate categories to address the alleged false claims individually. D.I. 63-1, Exs. C-E.

Guardant360 with Tempus’s xF+ is not false or misleading under § 43(a) of the Lanham Act, 15 U.S.C.A. § 1125(a). D.I. 1. Tempus filed counterclaims asserting that Guardant violated the Lanham Act, California Unfair Competition Law, and the Uniform Deceptive Trade Practices Act. D.I. 77. Tempus also seeks an injunction enjoining Guardant from publishing and disseminating various advertisements. Jd. On November 10, 2025, Tempus filed this Motion seeking to “stop Guardant from disseminating false ads about Tempus’s cancer biopsy products.” D.I. 62 at 1. Il. LEGAL STANDARD “A preliminary injunction is an extraordinary remedy never awarded as of right.” Winter v. Nat. Res. Def. Council, Inc., 555 U.S. 7, 24 (2008). A party may be granted a preliminary injunction only “upon a clear showing that the plaintiff is entitled to such relief.” Id. at 22 (citation omitted). To determine whether to grant or deny a preliminary injunction, the court considers whether the moving party would likely succeed on the merits, whether the moving party would suffer irreparable harm without injunctive relief, whether granting the injunction will cause greater harm to the nonmoving party, and whether the injunction serves the public interest. Holland v. Rosen, 895 F. 3d 272, 285-86 (3d Cir. 2018). The moving party bears the burden of persuasion, and the court may not grant the motion unless the movant satisfies the first two gateway factors. Id. As applicable to this case, under the Lanham Act, “[a] plaintiff seeking any such injunction shall be entitled to a rebuttable presumption of irreparable harm . . . upon a finding of likelihood of success on the merits for a violation identified in this subsection.” 15 U.S.C. § 1116(a). DISCUSSION Upon analyzing the factors that warrant preliminary injunctive relief, the Court finds that Tempus has failed to demonstrate the need for preliminary injunctive relief based on the reasons discussed below.

A. Tempus Fails to Show a Likelihood of Success on the Merits The underlying claim to Guardant’s complaint for declaratory judgment is § 43(a) of the Lanham Act, which prohibits false advertising in interstate commerce. Section 43(a) provides, in pertinent part: (1) Any person who, on or in connection with any goods or services, ... uses in commerce any ... false or misleading description of fact, or false or misleading representation of fact which . . . (B) in commercial advertising or promotion, misrepresents the nature, characteristics, qualities, or geographic origin of his or her or another person’s goods, services, or commercial activities, shall be liable in a civil action by any person who believes that he or she is likely to be damaged by such act. 15 U.S.C. § 1125(a).

Free access — add to your briefcase to read the full text and ask questions with AI

Related

Pernod Ricard USA, LLC v. Bacardi U.S.A., Inc.
653 F.3d 241 (Third Circuit, 2011)
Hybritech Incorporated v. Abbott Laboratories
849 F.2d 1446 (Federal Circuit, 1988)
Toro Co. v. Textron, Inc.
499 F. Supp. 241 (D. Delaware, 1980)
Groupe SEB USA, Inc. v. Euro-Pro Operating LLC
774 F.3d 192 (Third Circuit, 2014)
Adams v. Freedom Forge Corp.
204 F.3d 475 (Third Circuit, 2000)
Brittan Holland v. Kelly Rosen
895 F.3d 272 (Third Circuit, 2018)
Benihana of Tokoyo, Inc. v. Benihana, Inc.
828 F. Supp. 2d 720 (D. Delaware, 2011)
Instant Air Freight Co. v. C.F. Air Freight, Inc.
882 F.2d 797 (Third Circuit, 1989)

Cite This Page — Counsel Stack

Bluebook (online)
Guardant Health, Inc. v. Tempus AI, Inc., Counsel Stack Legal Research, https://law.counselstack.com/opinion/guardant-health-inc-v-tempus-ai-inc-ded-2026.