It may feel like there has been a stream of stories about drugs used for weight loss in 2023, but get ready for double helpings in 2024. A more potent fat-busting injection will probably enter clinics and we will see further trial results for a smorgasbord of treatments in the pipeline.
Semaglutide, possibly the most talked-about medicine of 2023, was developed to treat diabetes and sold as the self-injectable Ozempic. It works by mimicking the action of a gut hormone called GLP-1. Normally pumped out by the body after eating, this makes us feel full, quells appetite and boosts the release of insulin, a hormone involved in regulating blood sugar.
Since another injectable version of semaglutide called Wegovy was launched for weight loss in people without diabetes in the US in 2021, and later in parts of Europe, demand for both soared. As the maker of these drugs, Danish firm Novo Nordisk, couldn鈥檛 keep up, supplies ran short in the US and launches were delayed elsewhere, sparking a glut of headlines in 2023.
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In 2024, however, a recently approved weight-loss drug called Zepbound (tirzepatide) will probably become widely used in the US, and elsewhere further down the line. This works by mimicking not only GLP-1, but also another gut hormone called GIP. Zepbound鈥檚 arrival may ease supply shortages of the existing drugs 鈥� and it won鈥檛 hurt that its US price has been set at several hundred dollars per month less than Wegovy.
While Zepbound and Wegovy haven鈥檛 been compared in head-to-head trials, separate studies comparing them with a placebo suggest that the former could be superior 鈥� helping people lose 21 per cent of their body weight compared with 15 per cent. 鈥淭he drugs are getting more powerful,鈥� says at the University of Toronto in Canada.
Another access issue has been the reluctance of US health insurers to fund weight-loss drugs, but the number of employer-based insurance providers that plan to cover this medicine class is set to rise to 43 per cent in 2024, up from 25 per cent in 2023, . 鈥淚 would hope that increased numbers of medicines will translate into more competition, improved access and less expensive medicines,鈥� says Drucker.
Zepbound aside, other weight-loss drug candidates on the more distant horizon might prove to be more effective still. GLP-1 and GIP aren鈥檛 the only hormones released after eating. Others include PYY, also made by the gut, as well as glucagon and amylin, produced by the pancreas.
In 2024 and beyond, we will learn more about the relative effectiveness of medicines that mimic various combinations of these hormones. They include an injection that contains both semaglutide and an analogue of amylin, one that mimics GLP-1 and glucagon, and another that does this for three hormones 鈥� GLP-1, GIP and glucagon 鈥� which has earned it the nickname 鈥渢riple G鈥�.
Yet more progress could come with possible pill versions of injectable weight-loss drugs, which some people would prefer. Final-stage trial results are due in 2024 for an oral form of Wegovy for those without diabetes.
鈥淲e鈥檙e only just starting with the innovation,鈥� says Drucker.
