Adherence to weight-loss drugs is far higher with Wegovy than older medicines

FILE PHOTO: Injection pens of Novo Nordisk's weight-loss drug Wegovy are shown in this photo illustration in Oslo

By Nancy Lapid

(Reuters) - Forty percent of patients who filled a prescription for Novo Nordisk's Wegovy to treat obesity in 2021 or 2022 were still taking it a year later, more than three times the rate of adherence with older medicines, according to an analysis of medical records and insurance claims data.

Only 13% of patients who started taking Contrave from Orexigen Therapeutics and 10% of those who started on Qsymia from Vivus between 2015 and 2022 were still filling their prescriptions a year later, researchers reported on Wednesday in the journal Obesity.

The findings involved 1,911 adults, 25% of whom received Wegovy, which belongs to a new class of anti-obesity medications known as GLP-1 agonists originally developed to treat type 2 diabetes. In addition to their affect on blood sugar, GLP-1 drugs also suppress appetite and promote a feeling of fullness.

Overall, 75% of participants were female, 76% were white, 16% Black, and 4.5% Hispanic. Most had private insurance.

Greater weight loss at six months was also associated with persistence at one year, the researchers found.

The study did not say why patients stopped taking the drugs.

Among privately insured individuals, adherence rates varied depending on the insurance carrier, the researchers found.

“Limitations in coverage and certain pre-certification criteria such as step therapy may contribute to non-persistence,” the researchers said.

A July data analysis by pharmacy benefits manager Prime Therapeutics of 4,255 people with commercial health plans who had been prescribed GLP-1 drugs in 2021 found that only about a third were still taking it a year later.

Wegovy, which reduced weight by around 15% in a pivotal clinical trial, was approved for obesity in June 2021 and has proved to be wildly popular.

About 6.8% of patients taking Wegovy in clinical trials discontinued treatment due to gastrointestinal issues and other adverse events.

Wegovy carries a list price of $1,349 per-package, while Eli Lilly's newer rival drug Zepbound is listed at $1,059.87 a month, although most patients will pay far less, especially if they have commercial insurance that covers the treatments.

"The high costs of novel anti-obesity medications and non-persistence with (these drugs) are increasingly becoming a concern and could inform decisions regarding coverage by third-party payers," said study leader Dr. Hamlet Gasoyan of the Cleveland Clinic.

Gasoyan said they undertook the study to better understand the use of the obesity treatments in clinical practice and barriers to their continued use.

(Reporting by Nancy Lapid; Editing by Caroline Humer and Bill Berkrot)