Exclusive-New data show most US patients now stay on Wegovy, Zepbound after a year

A recent analysis of U.S. pharmacy claims indicates a significant increase in patient persistence for GLP-1 weight-loss drugs, with 63% of those starting Wegovy or Zepbound in Q1 2024 remaining on therapy a year later. This represents a near doubling of persistence for Wegovy specifically, driven by factors such as easing supply shortages, expanding insurance coverage, and improved side effect management. For institutional investors, this trend signals robust long-term revenue potential for manufacturers like Novo Nordisk and Eli Lilly, alongside escalating cost considerations for health insurers and employers.

Analysis

A recent analysis of U.S. pharmacy claims by Prime Therapeutics reveals a significant improvement in patient persistence for GLP-1 weight-loss drugs, a key positive catalyst for manufacturers Novo Nordisk and Eli Lilly. The data shows that 63% of patients who started on Wegovy or Zepbound in early 2024 were still on the therapy twelve months later. This marks a substantial increase for Wegovy, with persistence rates nearly doubling from 34% for cohorts starting three years ago. This trend is attributed to easing supply shortages, which has improved access, along with expanding insurance coverage and more effective clinical management of side effects. While this strengthens the case for sustained, long-term revenue streams for these therapies, the analysis also presents a more nuanced long-term picture. A separate cohort analysis indicates a significant patient drop-off over a multi-year horizon, with only 14% of patients remaining on Wegovy after three years. This highlights a critical challenge for sustained use and suggests that while one-year adherence is improving, long-term retention remains a material headwind, amplifying cost-benefit debates for payers like employers and government agencies.

Key Decisions for Investors

• The near-doubling of one-year patient persistence for Wegovy strongly reinforces the bull case for Novo Nordisk and Eli Lilly, suggesting revenue models should be updated to reflect higher-than-previously-expected medium-term demand.
• Investors should closely monitor payer and employer reimbursement policies, as the improved persistence rates will amplify the total cost burden, potentially leading to stricter coverage criteria or formulary controls that could cap market penetration.
• Caution is warranted when extrapolating long-term growth, as the steep drop in persistence to just 14% at the three-year mark suggests the total addressable market for chronic, lifelong use may be smaller than short-term data implies.
• Consider the easing of supply shortages a key non-recurring driver of the recent persistence jump; any future manufacturing or supply chain disruptions for NVO or LLY would now pose a heightened risk to maintaining these improved adherence levels.