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Low adherence and increased cost in first year of taking GLP-1a drugs for weight loss

Updated: Jul 13, 2023

An analysis of real-world integrated pharmacy and medical claims data by leading pharmacy benefit manager Prime Therapeutics and Magellan Rx Management (a Prime Therapeutics company), has revealed that 68 percent of individuals who newly started glucagon-like peptide-1 agonist (GLP-1a) drugs for weight loss were no longer taking the drug after one year. The data also show a substantial increase in health care cost in the first year among those who also started the drugs.

Utilisation of these drugs has largely been driven by social media influencers – and with more than 41% of US adults identified as obese by the CDC – the demand for GLP-1a drugs for weight loss has surged.


For the study, Prime analysed integrated pharmacy and medical claims data from 16 million commercially insured members; the analysis was limited to members who newly initiated a GLP-1a between January 2021 and December 2021. Members were required to have an obesity diagnosis prior to this time, or a prediabetes diagnosis, or a body mass index of 30 or higher. Individuals were excluded from the analysis if they had a prior diabetes diagnosis or diabetes drug therapy. Please refer to the abstract for additional details and study design.

Among those individuals who initiated GLP-1a drugs for weight loss at one year follow-up, this real-world analysis found a significantly higher total cost of care, at US$7,727 per person. Adherence to these drugs was also poor, with just 27% of individuals taking GLP-1a drugs after one year. Among GLP-1a adherent individuals, the increase in costs was even higher, double that of the matched controls, at $13,218 higher total cost of care per person.


GLP-1a weight loss treatment rates vary by region and coverage decisions. Assessing historical utilisation and spend patterns, Prime forecasts that an increase of GLP-1a weight loss utilisation by 1% of an insured population would bring an additional US$14.50 per member per month (PMPM) expense for most self-insured employers – an increase of more than 5% of their entire drug spend budget.


“While the industry is poised to see broader approval of GLP-1a drugs for weight loss by the Food and Drug Administration in the near-term, our analysis shows that a large, upfront financial investment is required when treating weight loss with these drugs,” said Dr Joseph Leach, senior vice President and Chief Medical Officer at Prime. “We will need results of ongoing, multi-year studies to see if this treatment has downstream impacts on other health conditions, including cardiovascular events and diabetes development prevention, which are key benefits to weight loss management. Long-term impact on total cost of care also remains to be seen.”


The estimated US$11,500-$14,000 annual wholesale acquisition price for GLP-1a weight loss treatment, the Institute for Clinical Economic Review (ICER) cost-effectiveness analysis identified that GLP-1a weight loss therapies are over-priced two-fold to their expected value in weight loss associated reduction in cardiovascular events and diabetes development avoidance over a lifetime. The ICER findings, coupled with Prime’s analysis, indicate GLP-1a weight loss products should have a pharmaceutical manufacturer, patient-centred value-based arrangement with health plans or PBMs to ensure fair GLP-1a pricing.


“GLP-1a drugs and their use for weight loss have taken the health care industry by storm, but several issues must be resolved, including how to ensure that those who may benefit most have access while maintaining overall pharmacy benefit affordability,” said Dr David Lassen, Chief Clinical Officer at Prime. “While we hope to see additional data to refine our guidance, health plans should consider programs to help adherence to avoid medication waste and comprehensive therapy plans – which include diet and exercise – to help people on their weight loss journey.”

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