The Power of the Pharmacy Benefit Manager
CVS Caremark, the pharmacy benefit management (PBM) division of CVS Health, manages prescription drug benefits for millions of Americans on behalf of employers, health plans, and other clients. PBMs create drug formularies, which are lists of medications covered by an insurance plan. By controlling these formularies, PBMs wield significant power in negotiating prices and rebates with drug manufacturers. The recent decision to remove Zepbound, a blockbuster weight-loss drug from Eli Lilly, is a prime example of this power in action.
The Financial Driver: Price and Rebate Negotiations
The primary motivation behind CVS Caremark's decision is financial. With the rising cost of GLP-1 medications and high demand, PBMs are under pressure to manage expenditures for their clients. In this case, CVS Caremark was able to secure more favorable financial terms, including a lower net price, from Novo Nordisk for its competing GLP-1 medication, Wegovy, than what Eli Lilly offered for Zepbound. By prioritizing Wegovy on its standard formularies, CVS can deliver significant cost savings to its clients, who are often employers covering these benefits for their workforce.
This is not the first time CVS has made such a move. In 2022, a decision to remove the blood thinner Eliquis from its formulary was later reversed after significant backlash, though the dynamic demonstrates the PBM's use of formulary design to pressure manufacturers. This recent change with Zepbound follows the same pattern, leveraging the competition between manufacturers to lower costs.
Impact on Patients and Clinical Considerations
While the formulary change may benefit CVS's clients financially, it creates substantial disruption for patients who were stable and thriving on Zepbound. Patients were forced to switch to an alternative, Wegovy, regardless of their individual medical journey or tolerance to the medication.
Clinical data from the SURMOUNT-5 trial shows Zepbound produced greater weight loss outcomes than Wegovy. Patients on Zepbound lost an average of 50 pounds over 72 weeks, compared to 33 pounds for those on Wegovy. For some patients, Zepbound's dual-action mechanism (targeting both GIP and GLP-1 receptors) provides a better result or different side effect profile than Wegovy's single GLP-1 mechanism. Forcing a switch could lead to:
- Loss of progress: Patients might regain weight or lose the progress they achieved on Zepbound.
- Side effect concerns: A patient may have tolerated one medication better than the other, and switching could reintroduce intolerable side effects.
- Administrative burden: Healthcare providers and patients face extra work with new prescriptions, prior authorizations, and appeals.
Navigating the Change: A Patient's Guide
For patients affected by the CVS Caremark formulary change, there are several steps they can take:
- Talk to your doctor: Discuss the best course of action. Your doctor may be able to submit an appeal based on medical necessity, especially if you had negative side effects on Wegovy previously.
- File an appeal: Patients have the legal right to request a formulary exception. Providers can submit supporting documentation detailing the patient's medical history and why Zepbound is necessary.
- Explore other options: Look into manufacturer assistance programs, such as Eli Lilly's LillyDirect, which offers cash-pay options and may provide access outside of insurance.
- Understand plan exceptions: Some employers using CVS Caremark as their PBM may opt for a custom formulary that retains coverage for Zepbound, so it is important to check with your specific plan.
Zepbound vs. Wegovy: A Comparison
| Feature | Zepbound (Tirzepatide) | Wegovy (Semaglutide) |
|---|---|---|
| Mechanism of Action | Dual GIP and GLP-1 agonist | GLP-1 agonist |
| Manufacturer | Eli Lilly and Co. | Novo Nordisk |
| Weight Loss Efficacy | Superior weight loss in clinical trials (e.g., SURMOUNT-5) | Effective, but demonstrated less weight loss than Zepbound in head-to-head trials |
| CVS Caremark Formulary Status | Not on standard commercial formularies as of July 1, 2025 | Preferred agent on standard commercial formularies as of July 1, 2025 |
| Approved Indications | Obesity, overweight with comorbidities, obstructive sleep apnea | Obesity, overweight with comorbidities, reducing cardiovascular events in patients with established heart disease |
The Ongoing Battle Between PBMs and Drug Manufacturers
The formulary removal of Zepbound is another skirmish in the ongoing battle between PBMs and drug manufacturers over high drug prices. PBMs like CVS Caremark argue they are using their market leverage to bring down costs, while manufacturers like Eli Lilly are increasingly seeking direct-to-consumer routes to bypass PBM gatekeepers. These conflicts reveal the complex web of incentives in the U.S. pharmaceutical supply chain and how financial contracts can shape clinical decisions. Patients are often caught in the middle, facing disruptions and forced switches that can affect their treatment outcomes.
Forbes contributor Seth Joseph summarized the situation: "This decision with Zepbound underscores a troubling trend in which financial contracts between benefit managers and drug manufacturers are increasingly shaping clinical decisions". As the GLP-1 market continues to expand with new drugs and indications, these battles over access and affordability are expected to continue.
Conclusion
The decision by CVS Caremark to drop Zepbound from its standard formularies is a financial move driven by intense competition and cost pressures in the GLP-1 market. By preferring Wegovy, CVS aims to deliver lower costs for its employer clients. This, however, comes at the expense of patient choice and potential treatment disruption. The event highlights the powerful role of PBMs and the complex financial relationships that shape patient access to even the most effective medications. As the obesity treatment landscape evolves, patients and healthcare providers must continue to navigate these formulary changes and advocacy channels to ensure continuity of care.
