Barcelona patent court finds oxycodone and naloxone patent invalid due to added matter

Facts
Decision

On 19 December 2018 Barcelona Commercial Court Number 4 dismissed a patent infringement action brought by Mundipharma against two generics of its oxycodone and naloxone medicinal product for the treatment of pain (Targin) and upheld the defendants' counterclaim that the asserted patent was invalid.

Facts

Mundipharma holds European Patent EP2425825 (EP'825), entitled 'Pharmaceutical preparation containing oxycodone and naloxone'. Claim 1 of the patent relates to an oral sustained release pharmaceutical formulation comprising 10mg to 150mg of oxycodone hydrochloride and 1mg to 50mg of naloxone hydrochloride in a weight ratio of 2:1.

In April and May 2018 Mundipharma filed infringement actions against two generic companies, while also seeking preliminary injunctions.

The preliminary injunctions were initially granted ex parte, but were subsequently revoked based on the prima facie invalidity of Mundipharma's patent. The decisions revoking the preliminary injunctions were confirmed on appeal.

In the main proceedings on the merits, the defendants claimed that EP'825 was invalid due to:

• added matter;
• insufficiency of disclosure;
• lack of novelty; and
• lack of inventive step.

As regards added matter, the defendants argued as follows:

• The claims of the patent as granted amounted to combination of features, which was not individualised in the original application as filed.
• The claims of the patent as granted entailed an inadmissible generalisation of the original application as filed because they omitted essential features of the latter.
• The patentee's argument that the specific combination of features of Claim 1 derived from the examples of the application as filed would lead to an intermediate generalisation.

The patentee counterargued that all of the claimed features were preferred features within the application as filed and thus constituted a clear pointer that led to their specific combination. Mundipharma, by way of an ancillary claim, also filed an auxiliary request, claiming an oral sustained release pharmaceutical formulation comprising 20mg of oxycodone hydrochloride and 10mg of naloxone hydrochloride.

Shortly before the trial, the European Patent Office Opposition Division announced the revocation of the asserted patent due to added matter.

Decision

The court upheld the defendants' counterclaims and revoked the patent in a ruling deliberated by the three Barcelona patent judges.

The judgment first analysed all of the features of Claim 1 of the patent as granted – namely:

• the selection of oxycodone hydrochloride salt;
• the selection of naloxone hydrochloride salt;
• the amount of oxycodone hydrochloride (10mg to 150mg);
• the amount of naloxone hydrochloride (1mg to 50mg); and
• the specific 2:1 ratio

The court stated that there was no pointer in the original patent application that led to the specific five-element combination as ultimately claimed. Hence, the combination of features of Claim 1 could not be directly and unambiguously derived or deduced by the person skilled in the art.

Further, the judgment explained that the claims of EP'825 amounted to an inadmissible generalisation because they omitted essential elements of the invention as disclosed in the application as filed. More specifically, whereas the original application required the formulation to provide an invariable and independent release at all times, the claims of the patent as granted did not require such release to be invariable and independent.

The court found it unnecessary to further tackle the rest of the invalidity grounds brought by the defendants (ie, insufficiency of disclosure, lack of novelty and lack of inventive step).

The judge examined the validity of Mundipharma's auxiliary request and concluded that it also featured added matter on the grounds of selection and combination of features and inadmissible generalisation.

Mundipharma has not appealed this judgment. As such, the patent's revocation is final in Spain.

For further information on this topic please contact Núria Ribera​ at Grau & Angulo by telephone (+34 93 202 34 56) or email (n.ribera@ga-ip.com). The Grau & Angulo website can be accessed at www.ga-ip.com.