Commercial success is a nothing-burger for the EPO in Wegovy patent inventive step analysis (T 1701/22, Obesity treatment with semaglutide)

In recent years, Novo Nordisk's weight loss drug semaglutide, marketed as Wegovy for obesity and Ozempic for diabetes, has become a pharmaceutical phenomenon. As with most successful pharmaceutical products, the remarkable success of semaglutide means we can also expect some high profile IP disputes. In jurisdictions lacking provisions for patent term extension, semaglutide is expected to face generic challenge as early as 2026. However, in addition to composition of matter protection, Novo Nordisk have attempted to bolster protection for semaglutide with a number of life cycle patents. The recent Board of Appeal decision in T 1701/22 related to one of these patent families (expiring in 2033) covering pharmaceutical composition of semaglutide for use in treatment of obesity, at a specific dose and formulation pH. Novo Nordisk ultimately failed to convince the EPO that the patent was non-obvious in view of known use of GLP-1 receptor agonists such as semaglutide for weight-loss, despite post-published clinical data and expert testimonials proclaiming the game-changing nature of the drug. 

Case background

T 1701/22 related to EP 2866825, opposed by Teva and Galenicum Health. The granted claims of the patent specified the use of the GLP-1 receptor agonist semaglutide in a specific dosage and formulation for treating obesity. The Opposition Division revoked the patent on the ground that it lacked inventive step (Article 56 EPC). Novo Nordisk appealed this decision. Claim 1 of the main request on appeal specified: "A composition comprising the GLP-1 agonist semaglutide and one or more pharmaceutically acceptable excipients for use in the prevention or treatment of obesity, wherein said use comprises administration of said GLP-1 receptor agonist in an amount of at least 0.7 mg per week; and said composition is in the form of an aqueous formulation with pH between 3 and 10."

Closest prior art and formulating the technical problem

At the EPO, the assessment of inventive step follows the problem-solution approach, which includes identifying the closest prior art, determining the objective technical problem, and assessing whether the claimed solution would have been obvious to the skilled person. Applying the problem solution approach, the Board of Appeal identified three differences between claim 1 and the closest prior art, essentially amounting to all of the substantive features of the claim, i.e. the selection of semaglutide specifically, the dosage regimen and the pH of the formulation. At the priority date, semaglutide was known as a GLP-1 receptor agonist. There was no published clinical data demonstrating the therapeutic effect of semaglutide on obesity, but there was data available showing some weight reducing effects of semaglutide and other GLP-1 receptor agonists. 

Not a nothing-burger

The objective technical problem was thus formulated by the Board of Appeal as "how to put the treatment of obesity [...] into practice" (r.13). In essence, Novo Nordisk was faced with demonstrating to the EPO why the choice of semaglutide, at the particular dose and the particular pH specified in the claim, would have been non-obvious to a skilled person. 

Inventive step assessment: Clinical success does not equate to a unexpected technical effect

Novo Nordisk attempted an inventive step argument based on post-published evidence including clinical trial data and media reports proclaiming the remarkable commercial and clinical success of semaglutide. They submitted BBC reports in which experts described semaglutide as a "game changer" in obesity treatment compared to the only "moderate average weight loss" achieved with prior GLP-1 receptor agonists. The Board of Appeal was not impressed by these statements, however, and firmly rejected them as basis for establishing the presence of an unexpected technical effect of the claimed drug product. The Board of Appeal emphasised that commercial success could not retroactively establish inventive step if the claimed features were already suggested by the prior art at the relevant filing date. As the Board noted:

"The later description of semaglutide as a 'game changer' [...] is in line with what was already known in the field from the prior art at the relevant date of the patent, which had demonstrated its weight reducing effects in clinical trials" (r.23). 

The Board of Appeal noted that the closest prior art in fact already taught that semaglutide was suitable for treating obesity, and even suggested a dose range overlapping with the claimed range. The Board of Appeal was further of the view that the pH specified in the claim, was well within the expected pH range for such a drug product. Novo Nordisk was thus unable to convince the Board of Appeal that there was anything unexpected or non-obvious about the claimed drug composition, dose or pH. 

The approach of the Board of Appeal in this case reflects the established principle that inventive step must be assessed from the perspective of the skilled person at the priority date, based solely on the information available at that time. While post-published evidence can help to demonstrate a technical effect that was plausible but not explicitly proven at the filing date (G 2/21), it cannot remedy a fundamental lack of inventive step if the claimed solution would have been obvious-to-try.

Final thoughts

The Board of Appeal's treatment of this evidence highlights the difference between the patent concept of unexpected technical effect and unexpected commercial or clinical success. As discussed by the Board of Appeal in this case, even the most extraordinary of market performances does not necessarily indicate non-obviousness of the underlying technical solution provided by a drug product from a patent perspective. Even a product widely acknowledged as transformative in its field may be considered by the EPO to lack inventive step if the technical path to its development is found to have been obvious at the filing date. 

The EPO Boards of Appeal are always keen to avoid a hindsight-based assessment of inventive step (IPKat). In this case, the Board of Appeal took pains to avoid starting their analysis from the successful product and working backward, but instead focused on what the skilled person would reasonably have done based on the prior art teachings at the relevant date. For the Board of Appeal, the fact that semaglutide was listed among several GLP-1 receptor agonists in the prior art, with dosage ranges overlapping the claimed range, made it an obvious candidate to try for treating obesity, regardless of its later exceptional success. It was perhaps also critical that the post-published data did not directly compare the semaglutide drug product, at the claimed dose and pH, with enough other GLP-1 receptor agonists. Even the post-published clinical data was therefore not enough to convince the Board of Appeal that the selections were linked to surprising technical effect. The Patentee thus failed to convince that EPO that these features justified additional years of monopoly beyond the composition of matter patent for the drug. 

Further reading

• Functional claims for pharmaceutical formulations: Validity versus enforcement (T 2130/22) (Jan 2025)
• Plausibility as a moving target: Phase III clinical trial results sink second medical use patent (T 0816/22) (Jan 2025)
• The plausibility of diagnostic inventions: No data, no patent (T 0589/22) (April 2025)