Case No. S2021_006 | Judgment of 26 April 2022 | ‘Sorafenib tosylate’
Please see the report about the main hearing for some background information about the case.

In brief, Bayer HealthCare was seeking preliminary injunctive relief against Sorafenib Zentiva of Helvepharm, the Swiss branch of Zentiva.


The present litigation is about alleged infringement (and validity) of claim 12 of EP 2 305 255 B1 (see EPO Register), specifically claiming the tosylate salt of sorafenib as such; i.e. a classic compound claim.
Lately, EP 255 was held to be invalid both in Germany (Federal Patent Court, judgment of 29 September 2021 in cases 3 Ni 12/20 and 3 Ni 13/21) and the U.K. (judgment of 8 October 2021 in case [2021] EWHC 2690 (Pat); the Court of Appeal decided on 1 April 2022 to hear the appeal). Further (negative) judgments that I could get hold of have been issued in The Netherlands (ECLI:NL:RBDHA:2021:13616), and Spain (ECLI:ES:JMB:2021:2692A). A full summary of corresponding decisions is given in the judgment:
The judge-rapporteur’s expert opinion in the present case had provisionally held that the patent was invalid, similar as the outcome e.g. in UK and Germany. However, the final judgment is the exact opposit: It holds that claim 12 is likely valid, and a PI was issued accordingly.
The whole case hinges on the assessment of obviousness. The judgment discusses both WO 00/42012 A1 and Lyons et al. as potentially closest prior art. In both cases, the judgment holds that the skilled person would well have include the tosylate salt into a salt screening:
Further, the judgment holds that the skilled person would not have given up in view of the low solubility of the tosylate, but would rather also have aimed to test the dissolution rate:
However, the FPC was not convinced that the skilled person could have tested the dissolution rate of sorafenib tosylate with standard methods available at the priority date:
Accorginly, the skilled person would not have realized that sorafenib tosylate had a surprisingly high dissolution rate, despite its low solubility (about as bad as the free base):

Interestingly, EP 255 itself is totally silent about the advantages of the tosylate salt over other pharaceutical forms of sorafenib. However, EP 255 does disclose animal experiment that indicate an anti-cancer effect — which implies sufficient biovailablity. Accordingly, the judgment holds that experimental data that have only been generated after the filing date in support of the bioavalability are admissible.
Note that the judgment does not discuss ‘plausiblity’ here. Great!
The FPC acknowledges that its finding of presumable validity of claim 12 of EP 255 differs from the decisions in DE, GR, UK, NL and Spain. Briefly investigation the reasons, the judgment holds that it does not appear to have been disputed elsewhere whether the dissolution rate could have been measured with routine methods at the priority date. However, there is yet another difference over the judgments in the UK and NL: These two judgments hold that the skilled person would have synthesized sorafenib tosylate without any inventive activity (for it to be included in the salt screening), and that claim 12 was invalid for this reason — irrespective of whether or not the skilled person would have realized that sorafenib tosylate is suitable and efficient for oral administration. The FPC disagrees with this assessment (¶59):
Bei auf eine chemische Verbindung als solche gerichteten Patenten genügt es aber zur Begründung der erfinderischen Tätigkeit, wenn der beanspruchte Stoff eine überraschende Wirkung oder Eigenschaft aufweist.
The judgment refers to some (very) old decisions of the German Federal Supreme Court (X ZB 11/68 – Disiloxan; X ZB 2/71 – Imidazoline) and some decisions of the Boards of Appeal of the EPO in a footnote in support of this view. Sounds familiar, doesn’t it? But the judgment also refers to Ralf Uhrich’s PhD thesis ‘Stoffschutz’ (available in full text here) criticizing it. The latter is a phantastic read, indeed. Now, that could have been a very interesting aspect of the decision; but the discussion stops right there.
/MW
—
BIBLIOGRAPHY
Case No. S2021_006 | Judgment of 26 April 2022 | ‘Sorafenib tosylate’
Bayer HealthCare LLC
./.
Helvepharm AG
Panel of Judges:
-
- Dr. Mark SCHWEIZER
- Dr. Tobias BREMI
- Dr. Andreas SCHÖLLHORN
Judge-rapporteur:
-
- Dr. Tobias BREMI
Court Clerk:
-
- Dr. Lukas ABEGG
Representative(s) of Plaintiff:
Representative(s) of Defendant:
-
- Andrea MONDINI (Times)
- Robin ELLIS (Reddie & Grose), assisting in patent matters
—
JUDGMENT
—
PATENT IN SUIT
—
BE ON THE KNOW