Eli Lilly files its roadmap brief seeking summary judgment across every injury category

Eli Lilly and Company filed a "roadmap" brief on May 19, 2026 in the federal GLP-1 products liability litigation, laying out a series of motions that ask the court to exclude plaintiffs' expert witnesses and grant summary judgment on every category of alleged injury in the cases against it ^[1]. The filing was made in MDL No. 3094 in the U.S. District Court for the Eastern District of Pennsylvania, before Judge Karen Spencer Marston ^[1].

Lilly's brief identifies its three medicines at issue: Trulicity (dulaglutide), approved in September 2014 for type 2 diabetes; Mounjaro (tirzepatide), approved in May 2022 for type 2 diabetes; and Zepbound (tirzepatide), approved in November 2023 for chronic weight management ^[1]. Plaintiffs allege Lilly failed to adequately warn about gastroparesis, gallbladder disease, ileus, intestinal obstruction and other effects ^[1]. The brief notes that general causation in this phase is limited to four claimed injuries — gastroparesis, ileus, small bowel obstruction and gallbladder injuries — while the warning-adequacy phase has no injury limit and also touches on pancreatitis, malnutrition, micronutrient deficiencies, Wernicke's encephalopathy, muscle wasting, dehydration, acute kidney injury and aspiration ^[1].

What Lilly is asking the court to do

The brief proposes a review order for eleven motions, three of which are filed jointly with Novo Nordisk ^[1]. They include motions to exclude general causation opinions on gastroparesis, on ileus and obstruction, and on gallbladder disease; motions to exclude warning-adequacy and preemption opinions from three plaintiff experts; and motions for summary judgment on gastroparesis claims, ileus and obstruction claims, gallbladder claims, and remaining gastrointestinal and miscellaneous claims ^[1]. Two joint motions target opinions on drug mechanism and on animal studies ^[1].

Lilly's brief says gastroparesis claims still make up more than 60% of the MDL cases against the company ^[1]. On preemption — the argument that federal drug law blocks state failure-to-warn claims — Lilly asserts that claims are barred where "FDA considered and rejected additional gastroparesis warnings," and separately that there is clear evidence FDA rejected added warnings for malnutrition, micronutrient deficiency, Wernicke's encephalopathy and muscle wasting ^[1]. Preemption is decided by the judge, not a jury ^[1].

The filing also details limits in plaintiffs' expert lineup as Lilly describes it. Former FDA Commissioner Dr. David Kessler and former FDA medical reviewer Dr. David Ross offer no opinions about tirzepatide — that is, neither Mounjaro nor Zepbound — and Dr. Ross's gallbladder opinions cover only Trulicity labels from December 2017 through June 10, 2022 ^[1]. Lilly says plaintiffs offer no warning-adequacy expert at all for some alleged injuries, such as malnutrition and pancreatitis ^[1]. Plaintiffs withdrew one expert, Dr. David Madigan, as to Lilly after his deposition ^[1]. In total, ten plaintiff experts have Lilly-related opinions ^[1].

Novo Nordisk filed its own roadmap brief the same day, describing five motions against plaintiff experts on ileus and obstruction, persistent gastroparesis, gallbladder disorders, class-effect opinions and animal-study opinions ^[2]. The judge set the deadlines for these expert challenges and summary judgment motions on April 30 ^[2].

Why it matters for patients

Nothing in this filing changes the FDA-approved labels for Trulicity, Mounjaro or Zepbound, and nothing in it is a finding about whether these drugs cause the injuries claimed. These are one side's legal arguments. No rulings on the merits of the allegations have been issued ^[2].

The outcome still matters. If the court excludes the plaintiffs' causation experts or accepts the preemption arguments, large portions of the litigation could be narrowed or dismissed before any trial ^[2]. For people who filed claims — or are considering one — the gastroparesis, ileus, obstruction and gallbladder categories are the ones directly in play ^[1].

The separate vision-loss litigation, MDL 3163, involves NAION claims and is handled by the same judge ^[2]. It is not covered by Lilly's May 19 brief ^[1].

What happens next

Lilly said it would file its brief addressing Dr. Kessler's opinions by May 27, 2026 ^[1]. Rulings on the expert challenges and summary judgment motions are expected over several sessions in the following months ^[2].