^{Note: GLP-1 brands include Victoza, Trulicity, Saxenda, Ozempic, Rybelsus, Wegovy, and Mounjaro
Source: IQVIA LAAD pharmacy claims, PlanTrak projected pharmacy claims; US Market Access Strategy Consulting}

The new GLP-1

Mounjaro launched as a diabetes drug when only two out of the then nine GLP-1 therapies were indicated for obesity. However, an unprecedented mix of real-life results, social media awareness, and traditional media attention highlighted Mounjaro’s efficacy as not only a diabetes medication, but also its effectiveness in weight-loss. Thanks to transitional assistance – often in the form of bridge programs and denial conversions – some Mounjaro patients were able to initiate treatment of the new therapy outside of the usual diabetes treatment progression. This introduces a new dynamic where patient interests appear to be influencing the clinical positioning of the traditional GLP-1 diabetes market, fueled by renewed interest in the pharmaceutical weight loss industry. The underlying patient base for Mounjaro underscores the reality of the evolving patient and provider interest in GLP-1s. Not only do the sex and age demographics for Mounjaro patients lie somewhere between those of diabetes and weight loss GLP-1 patients,¹ but their health profiles also fall somewhere in between. 75% of patients who initiate a diabetes-indicated GLP-1 have filled metformin or another diabetes treatment prior to initiation, while the majority of weight-loss indicated GLP-1 initiators have had no prior fills of any diabetes products. Mounjaro patients’ histories are a bit of a mix: 56% of patients have evidence of a diabetes treatment before starting Mounjaro, but 39% are naïve to any prior diabetes pharmaceutical.

A similar story emerges when reviewing diagnosis profiles for new patients of each product type. As expected, most new patients filling diabetes products have been formally diagnosed with diabetes, while most weight loss patients have a diagnosis related to weight. Though Mounjaro is indicated for diabetes, only around half of new Mounjaro patients have a diabetes diagnosis, while a quarter have a weight-related diagnosis. Some patients may have diagnoses for both and would be counted as having diabetes.

^{Note: GLP-1 brands include Victoza, Trulicity, Saxenda, Ozempic, Rybelsus, Wegovy, and Mounjaro; Data from January 2021 through May 2023
Source: IQVIA LAAD pharmacy and medical claims; US Market Access Strategy Consulting}

Shapeshifting market

Today’s patients that initiate GLP-1 treatment – particularly the treatments with explicit weight loss indications or strong clinical data for weight loss – look less like the typical diabetes patients they used to resemble. The demand for Mounjaro, and to a lesser extent Wegovy, was swift and vast, but uptake was not isolated to those products alone. Ozempic (semaglutide for diabetes) is an example of an older, established GLP-1 that demonstrated weight loss effectiveness before Wegovy (semaglutide for obesity) launched; and as patients have struggled to get access for Wegovy or Mounjaro, Ozempic offers an alternative with better payer coverage. In fact, the proportion of new patients that filled Ozempic with no prior diabetes prescription was nearly a quarter of all new patients by May 2021, a figure that increased to a third of patients once Wegovy and Mounjaro brought more demand and interest from non-diabetic patients to the pharmacy counter. Such growth of diabetes-treatment-naïve patients is partly a reflection of GLP-1’s growing use as a first-line treatment in diabetes, but also demand for the weight loss benefits alone. This trend also underscores the likely “spillover” that occurred for Ozempic as heightened patient demand for Wegovy and Mounjaro encountered access and supply challenges.

Notably, the proportion of treatment naïve Mounjaro patients declined around the time that Mounjaro experienced a supply shortage and scaled back marketing, including transitional assistance, to ensure that product access and supply could be maintained for patients with diabetes as intended. As a result, an influx of patients who had been taking Mounjaro switched to filling Ozempic or Wegovy instead.²

^{Note: New patients are classified based on prior prescription activity; diabetes-naïve patients have no prior activity for metformin, GLP-1s, or other diabetes medicines such as insulins, DPP-4s, SGLT-2s, etc.
Source: IQVIA LAAD pharmacy claims; US Market Access Strategy Consulting}

Patient interests alone are not reshaping the GLP-1 market. Without providers to write prescriptions, demand for treatment cannot actualize as written prescriptions. Before Wegovy’s launch, the number of providers with at least one written GLP-1 prescription remained relatively stable. Yet, the availability – despite limited payer coverage – of effective, weight loss treatment had an amplifying effect on Wegovy and Mounjaro’s entry into the market. The total number of GLP-1-prescribing providers increased by 228% from July 2020 to May 2023.

When providers are broken out by specialty, it is internal medicine and all other providers that are growing the fastest and not endocrinologists/diabetes specialists. Where endocrinologists and diabetes specialists have historically prescribed GLP-1s, other provider specialties are either finding greater value in both the diabetes and non-diabetes benefits of new GLP-1s, and/or patients are requesting them. To that end, internists and other (largely OB/GYN and cardiology) specialists are adding GLP-1s to their prescribing and growing quickly within the prescribing pool. The proportion of non-endocrinologists or diabetes specialists prescribing GLP-1s has grown by over 5 percentage points in the past two years, making up almost 95% of all prescribing physicians. As the adverse health outcomes associated with obesity become increasingly publicized, the provider perspective on the condition has shifted, and providers across all specialties feel progressively more interested in writing off-label prescriptions for diabetes GLP-1s to treat obesity³.

^{Note: Growth relative to June 2020
Source: IQVIA LAAD pharmacy claims; US Market Access Strategy Consulting}

The future of the GLP-1 market

The spotlight on the GLP-1 market has also brought the conversation of weight loss as preventive care to the forefront, as well as reigniting discussions around drug prices and costs. In July of this year, a bill entitled the Treat and Reduce Obesity Act of 2023 was introduced in the Senate with the explicit goal of lifting Medicare’s coverage exclusion for weight loss products, arguing that obesity increases the risk of multiple chronic conditions and thus costs the government billions of dollars.⁴ Moreover, Novo Nordisk’s recent SELECT trial demonstrated that Wegovy reduces the risk of cardiovascular events. On the other hand, researchers have claimed that given the cost of these drugs, if only 10% of overweight Medicare patients filled branded products, it would cost Medicare $26.8B a year.⁵ Likewise, employers are currently grappling with increased demand from their workforce for coverage of obesity care while also assessing the risks of absorbing those extra costs.⁶

As more positive health data emerges from trials of weight loss products, the pressure increases on payers and employers to cover these products. Yet, there are still many unanswered questions surrounding their use and long-term effects. Will patients stay on these costly medications indefinitely? Do the weight and health benefits persist after discontinuing the product? And, ultimately, are diet and exercise more cost-effective – and for whom – for a healthier lifestyle? The answers to these questions, and many more, are yet to be determined but will be crucial to the future of what patient access will look like for these products.

Even as the GLP-1 market continues to grow and change, the improvements made for the treatment of chronic diseases like diabetes and obesity remain a positive development that can ultimately change the lives of countless patients around the world.

^1,2Mounjaro: A New Era of Preventive Care and Consumer Health - IQVIA

³https://www.nytimes.com/2022/11/22/well/ozempic-diabetes-weight-loss.html

⁴https://www.carper.senate.gov/wp-content/uploads/TROA-Bill.pdf

⁵https://www.nejm.org/doi/full/10.1056/NEJMp2300516

⁶https://www.axios.com/2023/05/04/employers-weight-loss-drugs