EPLAW PATENT BLOG

DK – FRESENIUS KABI V. ELI LILLY (PEMETREXED)

Posted: February 21st, 2019

Fresenius Kabi AB v/Fresenius Kabi and Fresenius Kabi Oncology Plc. (“Fresenius Kabi”) v. Eli Lilly and Company and Eli Lilly Danmark A/S (“Lilly”), the Danish Eastern High Court, 20 December 2018, Case number B-2735-17

The case concerns the infringement of Lilly’s patent DK/EP 1 313 508 (“DK/EP ‘508”) which relates to the use of the active ingredient pemetrexed in combination therapy with vitamin B12 and optionally folic acid (formulated as a so-called Swiss-type claim).

On 8 December 2017, the Danish Maritime and Commercial High Court granted a preliminary injunction against Fresenius Kabi’s medicinal product “Pemetrexed Fresenius Kabi” in Denmark (the decision was reported on the EPLAW Patent Blog on 22 December 2017, see the article here).

Fresenius Kabi appealed the decision to the Eastern High Court of Denmark, and on 20 December 2018, the High Court affirmed the preliminary injunction against Fresenius Kabi.

In essence, Lilly maintained its arguments from the first instance proceedings. Lilly thus argued, among other things, that “Pemetrexed Fresenius Kabi” infringed Lilly’s DK/EP ‘508 patent, on the basis of equivalence. In this connection, Lilly argued, inter alia, that the selection of the specific salt is irrelevant to the invention, and that it was obvious to the skilled person at the priority date that they could find an alternative salt.

Fresenius Kabi argued, inter alia, that “Pemetrexed Fresenius Kabi” did not infringe Lilly’s DK/EP ‘508 patent because “Pemetrexed Fresenius Kabi” does not contain pemetrexed disodium, which is the salt of pemetrexed mentioned in Lilly’s DK/EP ‘508 patent.

In addition, Fresenius Kabi argued that Lilly could not claim protection under the doctrine of equivalence, since Lilly had intentionally limited the scope of protection of the DK/EP ‘508 patent by amending the wording of the claims from “pemetrexed” to “pemetrexed disodium” due to an objection under EPC Article 123(2) during the prosecution of the patent application before the EPO.

Moreover, Fresenius Kabi argued that there was no infringement by equivalence since the use of the tromethamine salt of pemetrexed in “Pemetrexed Fresenius Kabi” was not obvious to the skilled person at the priority date.

The validity of the DK/EP ‘508 patent had been uncontested by Fresenius Kabi until shortly before the oral hearing of the case before the High Court, where Fresenius Kabi submitted a request for revocation of the DK/EP ‘508 patent with the Maritime and Commercial court containing new arguments and evidence in this regard. Fresenius Kabi also tried to introduce this evidence in the High Court proceedings. However, the High Court did not allow Fresenius Kabi to submit these arguments and evidence. Therefore, the High Court took as a basis when handing down the decision that the DK/EP ‘508 patent is valid.

In relation to the question of infringement by equivalence, the High Court firstly assessed the relevance of the prosecution file history. In this regard, the High Court stated that in case of unclear patent claims, it may be relevant to take into account whether the applicant itself limited such unclear claims before the patent authorities in order to comply with the requirements for novelty and inventive step.

However, limitations made due to objections under EPC Article 123(2) were not relevant in this connection. The High Court noted in this regard that the question of equivalents is not comprised by the EPO’s assessment of basis under EPC Article 123(2), and that the EPO only assesses whether the patent can be issued, but not the scope of protection of the patent in possible subsequent infringement proceedings.

The High Court further agreed with the Maritime and Commercial High Court that Lilly’s amendment was not made in order to overcome lack of novelty or lack of inventive step, but was made due to an objection under EPC Article 123(2). The High Court therefore found that the scope of protection of the DK/EP ‘508 patent was not limited to covering pemetrexed disodium only and that protection by equivalence could not be ruled out.

The High Court then assessed whether the essential part of the invention covered by the DK/EP ‘508 patent was found in “Pemetrexed Fresenius Kabi”. In this connection, the High Court found that the invention related to a treatment regimen, and that the essential part of the invention related to the use of the active ingredient pemetrexed in combination with vitamin B12 and optionally folic acid. The specific salt of pemetrexed was not essential to the invention, and the essential part of the invention was therefore found in “Pemetrexed Fresenius Kabi”.

Furthermore, the High Court found that Lilly had at least rendered it probable that

(i) the skilled person would understand that in relation to the invention’s beneficial effect on toxicity it is not important whether the salt is the disodium salt or another form of pemetrexed;

(ii) that the skilled person would assume that the invention could be carried out using pharmaceutically acceptable salts other than the disodium salt;

(iii) that the skilled person in this connection was familiar with tromethamine being generally suitable in pharmaceuticals; and

(iv) that it would be characterised as routine laboratory work to find alternative salts of pemetrexed with acceptable physico-chemical properties compared to the known product Alimta.

On that basis, the High Court confirmed the Maritime and Commercial High Court’s decision that Lilly had rendered it probable that the DK/EP ‘508 patent was infringed under the doctrine of equivalence.

A copy of the decision (in Danish) of the Danish Eastern High Court can be accessed here.
A copy of the decision (in Danish) of the Danish Maritime and Commercial High Court here.

Reported by: Mikkel Vittrup, Peter-Ulrik Plesner, Mette Hygum Clausen and Julie Brøndt Glarkrog, Plesner Advokatpartnerselskab, and Ejvind Christiansen and Casper Struve, Zacco, who advised Lilly during the PI proceedings in Denmark.

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