A class action lawsuit has been filed against CVS Caremark in the Southern District of New York after the pharmacy benefit manager removed Eli Lilly’s Zepbound from its standard formularies in favor of Novo Nordisk’s Wegovy. Plaintiffs argue the two drugs are not clinically interchangeable, citing differences in side effects, FDA-approved indications, and trial results. They point out that Zepbound is the only GLP-1 therapy approved for obesity with sleep apnea, that some patients tolerate one drug but not the other, and that studies suggest Zepbound may deliver greater weight loss than Wegovy.
CVS Caremark has defended its formulary decision as a strategy to promote competition and lower costs, saying an exemption process is in place for medical necessity cases. The company called the suit “without merit.”
The lawsuit reflects a broader debate within the medical community. At ESC Congress 2025, conflicting evidence emerged: a post hoc analysis suggested tirzepatide could offer greater long-term cardiovascular risk reduction, while the STEER real-world study favored semaglutide for major adverse cardiovascular events. Clinicians welcomed the STEER findings but cautioned that, as real-world data, they should be viewed as hypothesis-generating until confirmed in randomized trials.
On the Diabetes Dialogue podcast, experts advised prescribing based on labeled indications until more definitive evidence is available—semaglutide for cardiovascular and kidney protection, tirzepatide for obesity and sleep apnea. This shows why many providers view the two drugs as complementary rather than interchangeable, a central issue in the legal challenge.
Sources
Wegovy Outperforms Mounjaro in Cardiovascular Outcomes
CVS Shifts to Wegovy as Preferred Obesity Medication, Raising Questions About Access and Affordability
CVS Caremark Faces Lawsuit for Favoring Wegovy Over Zepbound
CVS Caremark hit with class action lawsuit over decision to drop Zepbound from formulary
Diabetes Dialogue: Semaglutide & Tirzepatide Updates at ESC Congress 2025
