Paris Court orders a preliminary injunction against Zentiva over generic pemetrexed

The ruling of the Paris Judiciary Court follows the judgment dated 11 September 2020 in a parallel case on the merits in which there was a full trial against Fresenius Kabi where the Paris Judiciary Court awarded pharmaceuticals manufacturer Eli Lilly €28 million in provisional damages, the highest of its kind ever ordered by any French court for patent infringement.

Parallel proceedings involving Eli Lilly and Zentiva have also taken place in several other European jurisdictions.

The patent in issue before the Paris Judiciary Court is a European patent that covers the use of the active ingredient pemetrexed disodium in combination with vitamin B12 or a pharmaceutical derivate thereof for inhibiting tumour growth. Eli Lilly's product is sold under the brand name Alimta.

The claims of Eli Lilly's patent as initially filed referred to the use of antifolates, the class of compounds to which pemetrexed belong, but were limited during examination to pemetrexed, in order to exclude other antifolates than pemetrexed. Following an objection from the examiner that, by doing so, Eli Lilly had added subject-matter it had not disclosed in the initial application as filed, Eli Lilly further limited the claims to pemetrexed disodium specifically, the preferred embodiment disclosed in the description.

In April 2019, Zentiva launched its generic product in France using a different salt of pemetrexed, pemetrexed diarginine. In June that year, Eli Lilly started infringement proceedings against Zentiva and subsequently applied for a preliminary injunction in March 2020. Zentiva argued, however, that its generic product was outside the scope of Eli Lilly's European patent because it used a different salt. However, the French court disagreed and found that Zentiva product was likely to infringe Eli Lilly's patent.

As in the case Eli Lilly v Fresenius Kabi, the French court found that despite the narrow wording of the patent claims, Eli Lilly's patent was not limited to pemetrexed disodium but instead covered combinations of B12 with any salts of pemetrexed. The court notably held that a person skilled in the art would know that the technical effect obtained by the combination of pemetrexed with vitamin B12 – a reduction in side effects – would be achieved irrespective of the specific salt form being used.

As a result, the French court held that Zentiva's product was likely to infringe the patent, if not literally then at least under the doctrine of equivalents. This finding is aligned with the position taken by the courts in most other jurisdictions in Europe in cases relating to pemetrexed, although in the case of Eli Lilly v Fresenius Kabi, the French court found that Fresenius Kabi's product literally infringed the patent, without the need to consider infringement by equivalence.

The court granted Eli Lilly a preliminary injunction against Zentiva which bars the company from, among other things, manufacturing, marketing or supplying its generic alternative to Eli Lilly's product in France.

Zentiva had developed an argument challenging the proportionality of such an injunction being ordered only a few months before the patent was due to expire. However, the court dismissed its argument on the basis that Zentiva did not establish why the injunction would be disproportionate, considering that the company was aware of the risks when it decided to launch its product while the patent was still in force. The court also said that after Fresenius Kabi had been injuncted, Zentiva remained the only generic maker on the market, and that it had thus enjoyed an unjustified economic advantage over other generic competitors planning to launch at expiry of the patent.

Jules Fabre of Pinsent Masons, the law firm behind Out-Law, said the court’s ruling in respect of the injunction appears to be in contrast with the position of the Paris Court of Appeal in the cases of MSD v Mylan and MSD v Sandoz in 2020.

In these judgments, the Paris Court of Appeal recalled that the EU’s directive on the enforcement of intellectual property rights requires courts, when deciding on applications for provisional measures, to assess whether such measures are proportionate, notably in view of the seriousness and irreparable nature of the harm suffered by the patentee. The court then considered that the burden of proof in this respect lies with the party that applies for a preliminary injunction, rather than on the defendant, and that, in these particular cases, MSD had failed to establish why its potential harm could not be adequately compensated by damages if it was successful on the merits of its case, particularly considering that that the supplementary protection certificate (SPC) at stake was due to expire less than a month after the first instance judgments in these case.

In addition to granting Eli Lilly the preliminary injunction, the Paris Judiciary Court ruled that Zentiva was liable for €4m in provisional damages, an amount calculated on the basis of a 25% royalty rate on Zentiva's estimated revenues. Marina Jonon of Pinsent Masons said this now appears to be the Paris court's standard rate when calculating damages on the basis of a royalty in pharmaceutical cases.

However, unlike in the Eli Lilly v Fresenius Kabi case, Eli Lilly did not seek additional damages based on unfair competition to be paid by Zentiva to its French affiliate and distributor Eli Lilly France. In Eli Lilly v Fresenius, this accounted for the majority of damages, with Fresenius Kabi ordered to pay €8m of damages based on patent infringement to Eli Lilly and Company – the holder of the patent – and €20m of damages based on unfair competition to Lilly France – the French affiliate and distributor.

Zentiva has lodged an appeal against the interlocutory judgment, which is pending. Proceedings on the merits of Eli Lilly’s case are also pending before the court of first instance in France.