SWITZERLAND Trends and Developments Contributed by: Simon Holzer, Ulrike Ciesla, Louisa Galbraith and Michael Ritscher, MLL Legal
cants of the first filing, for whom no written dec- larations of assignment were submitted to the court, were not considered proven. The patent in suit EP 255 therefore validly claims its priority. The starting point for the assessment of inven- tive step was a scientific article, Lyons et al 2001, describing the Raf signalling pathways and explaining why the inhibition of Raf kinase is a promising approach for the destruction of tumors. A clinical trial with an oral formulation of “BAY 43-9006” is reported in this article. The drug was well tolerated, and the dose was increased. Preliminary clinical data are encour- aging, with at least 37% of patients showing sta- ble disease progression for more than 12 weeks. The term “BAY 43-9006” used in Lyons et al stands for sorafenib. However, the Federal Pat- ent Court concluded that the scientific article does not directly and unambiguously disclose the tosylate salt of sorafenib nor the free base. Therefore, one cannot simply assume that the article discloses the free base or the tosylate salt of sorafenib, as this would already read an ele - ment of the solution into the starting point for the assessment of inventive step. Ultimately, and this is probably the main rea- son why the Federal Patent Court arrived at an assessment that differs from that of foreign courts in parallel proceedings, the overall view must not be neglected when considering the individual steps leading to an invention. If several steps are necessary to arrive at the subject mat- ter of the invention, this is considered a “clear indication of the existence of an inventive step”, although this should not apply if each individual step is obvious from the point of view of what has been achieved and the problem still to be solved.
In order to include sorafenib tosylate as a can- didate in (pre)clinical testing, the skilled person in the present case must: • (1) include the tosylate salt in the salt screen- ing; • (2) despite the very low solubility of the salt, nevertheless attempt to determine its dissolu- tion rate; • (3) successfully determine the dissolution rate and establish that it is higher than that of other salt forms; and • (4) consider the tosylate salt as a promising candidate despite the still low dissolution rate, that it is higher than that of other salt forms, whereby it should be noted that at least step (2) is not associated with a very high expectation of success. There may be reasons to carry out each indi- vidual step, as the defendant has shown. How- ever, the fact that the skilled person performs all steps without inventive step was not proven in the opinion of the Federal Patent Court. If the skilled person only makes one “wrong turn” or finds the result of the respective step insufficient to continue, the skilled person does not arrive at the subject matter of the invention. Even if the skilled person would have to assume on the basis of Lyons et al 2001 that there is a clini- cally effective, ie, sufficiently bioavailable, form of sorafenib, it is not obvious that this is in the tosylate salt. Based on these considerations, the Federal Patent Court acknowledged the pres- ence of an inventive step. Therefore, the Federal Patent Court confirmed the validity of the Swiss part of EP 255 and found EP 255 to be infringed. The judgment has not been appealed and is therefore final.
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