Posted: November 4th, 2020
On 27 October 2020, the Court of Appeal of The Hague (“CoA”) delivered its judgment in a case between Eli Lilly and Company (“Lilly”) and Fresenius Kabi Nederland B.V. (“Fresenius”). The case for Lilly relates to its patent which protects, inter alia, Lilly’s product Alimta® in combination therapy with vitamin B12 and folic acid. The case involves the assessment of infringement and validity.
Turning to infringement first. The main legal issue relates to the assessment of the patent’s scope of protection. The claimed combination therapy literally refers to the disodium salt form of pemetrexed. Fresenius developed a generic version of Alimta® albeit with a different pemetrexed salt form. Instead of using pemetrexed disodium, Fresenius used the tromethamine salt form in an attempt to escape patent infringement.
Main issue: is the use of a pemetrexed salt form other than pemetrexed disodium covered by the scope of protection of the patent?
The CoA answered the question in the affirmative. The CoA considered that the generic pemetrexed product marketed by Fresenius constitutes patent infringement under the doctrine of equivalence, reversing the decision of the District Court of The Hague of 19 June 2019. The CoA issued a permanent injunction which means that Fresenius is enjoined from marketing its generic pemetrexed product in the Netherlands.
Legal test: two-step approach
For the assessment of the scope of protection, the CoA faced the task of striking the right balance between the two extremes as referred to in article 69 of the European Patent Convention (“EPC”) and the Protocol on Interpretation of Article 69 of the EPC (the “Protocol”). More specifically, the CoA had to strike a balance between relying on the literal wording of the claims and relying on the claims as a mere guideline for determining what the skilled person would perceive as the claimed subject matter.
The CoA adopts a two-step approach for the assessment of the scope of protection. This approach is consistent with the approaches seen elsewhere in Europe. The first step is the assessment of whether the product literally satisfies the features of the claim. If not all features are literally satisfied, then a second step is needed to assess whether the distinguishing elements of the product are equivalent to the features of the patent pursuant to Article 2 of the Protocol.
For the assessment of the second step, the CoA considers that the following questions require answering:
1. Is the distinguishing element of the product a technical equivalent compared to the claimed feature?
2. From the point of view of fair protection for the patentee: is it appropriate to take into account equivalent elements when determining the scope of protection?
3. From the point of view of a reasonable degree of legal certainty for third parties: is it appropriate to allow protection for equivalent elements?
4. Is the variant novel and does it involve inventive step over the prior art relevant to the patent?
The CoA considered that that the tromethamine salt form of pemetrexed does not constitute a literal infringement of the patent. This meant that the CoA needed to assess the questions under the second step.
Regarding the first question: the CoA considered that the tromethamine salt form of pemetrexed is a technical equivalent to pemetrexed disodium. Fresenius admitted biological equivalence, but raised the argument that bioequivalence cannot be equated with technical equivalence in patent law. The CoA rejected this argument by considering that the tromethamine salt form of pemetrexeds performs the same function in the context of the invention. Moreover, the CoA considered that there is equivalence at the level of the biological effect in the patient after administration and at the level of the pharmaceutical preparation, i.e. is it the pemetrexed anion that is responsible for the efficacy and toxicity of the drug and the cation (i.e. the salt) is merely used as a ‘carrier’ of the anion.
Regarding the second question: the CoA considered that the skilled person would understand that the claimed invention can also be performed with the use of a different salt form of pemetrexed. According to the CoA, the skilled person would even be encouraged by the patent description to search for alternative salt forms of pemetrexed for use in the invention, and that the selection of such an alternative salt form is a routine exercise. Therefore, the requirement of fair protection for the patentee does not preclude Lilly from relying on the doctrine of equivalence.
Regarding the third question: the CoA considered that the skilled person would appreciate that the teaching of the patent is broader than the literal wording of the claims. It also considered that there is no good reason to assume that the scope of protection is limited to the use of pemetrexed disodium. In particular, the CoA had looked at the prosecution history of the patent and considered that Lilly had tried to get a claim for “pemetrexed” but that the examiner refused such a claim by raising an added matter objection, which caused Lilly to amend the claim to “pemetrexed disodium”.
The CoA considers that such an amendment to overcome an added matter objection does not preclude the patentee from relying on the doctrine of equivalence. According to the CoA, the assessment of added matter and the assessment of the scope of protection are distinctive assessments which should not be mixed. Therefore, the requirement of a reasonable degree of legal certainty for third parties does not preclude Lilly from relying on the doctrine of equivalence.
The fourth question did not require answering as there was no position to assert that the generic pemetrexed product lacks novelty or inventive step over the prior art relevant to the patent.
In the light of the answers to these questions, the CoA concludes that the tromethamine salt form of pemetrexed falls within the scope of protection of the patent under the doctrine of equivalence.
Fresenius put forward a lengthy inventive step attack against the patent. The CoA considered that this attack should fail and that the patent should be considered valid. This validity outcome is similar to what the District Court of The Hague ruled on 16 January 2019 in the validity case between Lilly and Sandoz.
Summary and translation: Klaas Bisschop, Dirk-Jan Ridderinkhof and Joost Duijm, Hogan Lovells