What impact will Wegovy have on the obesity epidemic?

The latest injectable glucagon-like peptide-1 receptor agonist (GLP-1RA), Wegovy, became available in Australia last week (5 August 2024).

Indicated by the Therapeutic Goods Administration (TGA) for adolescents and adults as an ‘adjunct to a reduced-energy diet and increased physical activity when specific criteria are met,’ the medicine is approved specifically for weight loss and management.

Australian Pharmacist investigates what this could mean for weight management, GLP-1RA supply and chronic disease prevention.

What impact will Wegovy have on medicine shortages?

Global demand for GLP-1RAs has led to ongoing medicine shortages that have persisted for up to 2 years.

Most GLP-1RAs (except Saxenda and Victoza) are currently in short supply, with the TGA indicating that stock of the following medicines is expected to be replenished on:

• Mounjaro: 31 August 2024
• Trulicity: 31 December 2024
• Ozempic: 31 December 2024.

This had made it difficult for patients prescribed these medicines to continue ongoing therapy, said credentialled diabetes educator Kirstin Turner MPS, PSA ACT Pharmacist of the Year 2024.

‘A lot of patients were initiated on [these medicines] and titrated up to their maintenance dose before the shortages happened,’ she said. ‘Those patients have really suffered in this timeframe, and have had to potentially be supplemented with insulin or unable to afford going on a Sodium-Glucose Transport Protein 2 (SGLT2) Inhibitor as well as an on-and-off GLP-1RA.’

Changes to the Pharmaceutical Benefits Scheme (PBS) since Ozempic was introduced has also made it more difficult to qualify as a candidate for the medicine.

‘Originally it could be prescribed as second-line therapy, then it was adjusted so you had to be intolerant to gliclazide,’ said Ms Turner. ‘Now patients must have trialled and be intolerant or unresponsive to an SGLT2, as well as metformin or gliclazide.’

The TGA said it’s not known what impact the introduction of Wegovy will have on the availability of Ozempic.

But a spokesperson for Wegovy manufacturer Novo Nordisk, which also produces Ozempic, told AP they have ‘worked hard for 2 years to ensure a stable supply of Wegovy 2.4 mg in Australia for eligible patients’.

‘This has included a heavy investment of nearly $24 billion in the last 2 years in production to increase capacity,’ the spokesperson said.

‘Now that Wegovy 2.4 mg is launched, eligible patients will be able to start and remain on treatment in confidence, providing surety to patients and their treating physicians.’

But it’s too early to tell if there will be any supply issues, Ms Turner thinks.

‘There’s still a supply issue for one medicine, and now a newer version of the same medicine with a different indication is being introduced,’ she added.

Can patients switch from Ozempic to Wegovy?

The TGA indicated that Wegovy cannot be dispensed using a prescription for Ozempic, and that a new prescription for Wegovy will need to be provided if appropriate.

It will also need to be considered what dose to start patients on Wegovy when making the switch from Ozempic, said Ms Turner.

‘[For example], if a patient is on 1 mg of Ozempic, [perhaps] they are put on 1 mg of Wegovy, then titrated up,’ she said.

‘It just depends how quickly GPs want to switch their patients over, because if they are able to get Ozempic privately, they might not want to change to a more expensive medicine.’

At the recommended maintenance dose (2.4 mg once weekly), a month’s supply of Wegovy costs $460. Lower-dose pens (0.25 mg, 0.75 mg, and 1.0 mg) cost $260 per month, with the 1.7 mg option priced at $380 per month.

‘There’s a significant price difference between a private prescription of Ozempic and Wegovy by as much as $100 per month,’ Ms Turner said.

What impact could Wegovy have on long-term weight loss?

More than two thirds (67%) of Australian adults are overweight or obese. Clinical studies have revealed that around 1 in 3 people lost greater than 20% of their body weight with Wegovy, said the Novo Nordisk spokesperson.

‘When ​used as an adjunct to diet and exercise over 68 weeks mean weight loss [was] 15–17%,’ the spokesperson said.

Before the introduction of Wegovy, Saxenda was the only GLP-1RA indicated specifically for weight loss, said Ms Turner.

‘However, it’s a daily injection,’ she said. ‘So convenience-wise, most people would rather jab themselves weekly.’

It’s helpful to have another injectable medicine indicated specifically for weight loss in the toolbox, particularly for those who have underlying metabolic diseases and/or dysfunction, said Ms Turner.

‘Patients who may already have high blood pressure, type 2 diabetes, high cholesterol, or a family history of those conditions, [might] be overweight or obese,’ she said.

Most patients who need to lose weight also have central adipose tissue, which is a cardiovascular risk factor.

‘By reducing adipose tissue, as shown in Ozempic clinical trials, cardiovascular protection is a preventative step,’ said Ms Turner.

However, medicines such as Wegovy licensed for chronic weight management are destined for long-term use.

‘There’s no end to therapy and no guidelines on when or how to stop it,’ said Ms Turner. ‘It’s considered to be potentially lifelong.’

There is also a significant possibility of relapse when patients stop using GLP-1RAs, meaning patients can gain back almost everything they’ve lost. So a multidisciplinary approach is required to ensure long-term success in weight management.

‘Whether that’s the introduction of allied health professionals, such as a dietitian or exercise physiologist, a GP or specialist involvement, a collaborative approach is essential,’ she said.

‘Then pharmacists are there to make sure the medicine is used appropriately, at the right dose, and adverse effects and intolerance are monitored.’

Is there a patient demand?

Ms Turner has already been asked about Wegovy by a patient who is overweight, and has hypertension, type 2 diabetes and sleep apnoea during a recent Home Medicine Review.

The patient, who is also insulin resistant and has borderline hyperlipidemia, takes metformin. While well tolerated, he is yet to lose any weight.

‘His cardiovascular risk factors are up there, and he has been asking the doctor about losing weight for a while,’ said Ms Turner.

‘He had asked about Ozempic, and I explained the PBS limitations. Then he said, “Isn’t there another one on the market now, starting with W?”’

While Ms Turner said she would happily discuss Wegovy with the patient’s GP as an add-on therapy, she made it clear that it must be paired with diet, exercise and lifestyle interventions.

‘Patients with insulin resistance gain weight at the drop of a hat, and it’s very difficult for them to lose weight so they lose motivation very quickly,’ she said. ‘Just starting the medicine could be the kickstarter he needs to actually start losing weight.’