FCJ holds that the technical problem for a medical use claim is not simply providing a new medical use of the known drug
Case Law | 04.02.2025
Many cases turn on the exact formulation of the technical problem to be solved when assessing inventive step. In X ZR 92/23, Hoffmann Eitle attorneys Peter Klusmann, Jan Carl Zillies, Dirk Schüßler-Langeheine, Clemens Tobias Steins, and Melanie Schain persuaded the German Federal Court of Justice (FCJ) to avoid hindsight by formulating the technical problem as providing an effective remedy for the specified treatment, rather than as finding new fields of use for the specified drug. The FCJ also acknowledged that even if it seems possible from the prior art that the drug could have the necessary properties for the treatment, there needs to be a sufficient expectation of success to establish obviousness.
The case at hand related to a second medical use claim: mirabegron for use in the treatment of overactive bladder. It was known that other compounds stimulating the ß3-adrenoceptor can alleviate symptoms of overactive bladder, and that high selectivity for this receptor is desired. Mirabegron was discussed in the prior art as having ß3-adrenoceptor activity as were a large number of other compounds, and it was known that not all of these other compounds were equally suitable for the treatment of overactive bladder.
A lower court (the Federal Patents Court) had revoked the patent: they defined the technical problem as finding new uses for mirabegron, and held that providing an additional treatment with a known active ingredient was obvious.
The FCJ overturned this decision. Irrespective of whether the starting point is the effect of ß3-adrenoceptor agonists on overactive bladder or the use of mirabegron for the treatment of other diseases, the technical problem was formulated as providing an effective remedy for the treatment of an overactive bladder. Although this decision is in line with former FCJ decisions, it is still remarkable in the field of second medical use claims for the formulation of the technical problem and thus for the assessment of inventive step. According to the FCJ, the technical problem is to be formulated rather broadly, and providing new fields of use is not an appropriate formulation simply because the patent in suit relates to an additional indication for a known active ingredient. If there are any implications for the assessment of inventive step arising from the formulation of the technical problem, then it is likely worded incorrectly.
Meanwhile general suggestions and indications were not sufficient (here, for example, the interaction of mirabegron with the ß3 receptor) to establish obviousness. Rather, specific indications are required for establishing a reasonable expectation of success.
All in all, this decision represents a significant development in the assessment of inventive step of second medical use claims in Germany. It will be welcome news to patentees seeking to protect their new developments in this important field.