Patent data reveals push to use weight-loss drugs for treating cancer

While GLP-1 drugs were initially developed as a Type 2 diabetes medication, the appetite-suppressing side effects meant that they quickly became more widely recognised as a weight loss treatment. However, research by Pinsent Masons into global patent application data now shows a further broadening of the intended purpose for those products at a time when original patent protection for some GLP-1 weight-loss drugs has been expiring.

Pinsent Masons found that there was a 28% increase in the number of patent applications filed globally relating to GLP-1 drugs, from 726 to 936 in the year to 31 March 2026.

Patent law expert Christopher Sharp of Pinsent Masons, said: “The potential for GLP-1 drugs to treat a much wider range of illnesses is pushing pharmaceutical companies to reformulate their existing drugs. Developing improved formulations of GLP-1 drugs can help pharmaceutical companies secure longer-term patent protection. That can help them extend the commercial value of their drugs.”

“For most pharmaceutical companies, the priority is securing additional patent protection for GLP-1 drugs in the US. That's the world’s largest pharmaceutical market and where the biggest commercial prospects lie. That said, the European and Asia-Pacific GLP-1 markets are rapidly expanding,” he said.

“Developing a new drug like GLP-1 can take billions in investment and years of testing. It is only natural that pharmaceutical companies want to maximise and extend the value of that effort in the long run across all markets. Pharmaceutical companies can develop and patent follow-on drugs with alternative uses or formulations to help offset the loss of revenue when lower-cost generics enter the market,” Sharp added.

According to Pinsent Masons, in the year to 31 March 2026, there were 399 GLP-1 patent applications filed for the treatment of Type 2 diabetes, 194 related to liver diseases, 170 related to hypertension, 150 related to stroke, 124 related to kidney disease, and 77 related to sleep apnoea. Other conditions targeted by GLP-1 patent applications include cancer (121 patent applications), Parkinson's disease (97), addiction (47) and polycystic ovary syndrome (33).

The research also found that pharmaceutical companies are seeking to extend the shelf-life of their patents by developing innovative manufacturing and delivery methods and new formulations for GLP-1 drugs. In the last year, there were 49 patent applications relating to oral formulations of GLP-1 drugs. At present GLP-1 drugs are typically self-administered by injection.

Advertising compliance expert Emily Swithenbank of Pinsent Masons said the marketing of GLP-1s for weight loss treatment and adjacent products has been a really hot topic over the last 12 months for the UK’s Advertising Standards Authority (ASA). It has dealt with many complaints and is actively monitoring for ad compliance in this area. The interest increased further with the approval of GLP-1s in tablet form in June 2026.

“The perception may be that GLP-1 drugs are readily available for consumers and, as such, can be directly marketed to the public,” Swithenbank said. “However, GLP-1 products are products which are prescribed only by medical professionals. Because they fall into the category of prescription-only medicines, they cannot be advertised to consumers. 

“Similarly, claims that such products treat or target particular conditions – so-called ‘health claims’ – may only be made in respect of regulated products for which approval has been granted. So, claims that GLP-1s treat other conditions for which marketing authorisation has yet to be obtained cannot be made. What we've seen come across the desk of the ASA are products which claim to have similar benefits to GLP-1 products or otherwise achieve the same results as those types of products. Such marketing is going to be found to fall foul of the advertising rules. The ASA has given a number of rulings which confirm that those types of claims cannot be made,” she said.