Learning from Case Law: Case C‑456/24, AG opinion on whether or not a Supplementary Protection certificate (SPC) can be granted for an excipient

This post is an attempt to provide salient information on Case C-456/24 which concerns Halozyme Inc. vs the Supreme Administrative Court, Czech Republic.

Specifically, it concerns the events leading up to the CJEU getting involved in the case as well as the opinion of Attorney General Emiliou delivered in a preliminary ruling on 23 April 2026 which attempts to answer the question posed in the title of this post.

Background to the case

Year/Date	Event
2000	Trastuzumab is a monoclonal antibody used as an active substance in the treatment for breast cancer and other malignancies. It has been marketed in the European Union since the early 2000s in a medicinal product known as ‘Herceptin’, by Roche, a pharmaceutical company not directly involved in the present proceedings. In 2000, Roche was granted an MA by the European Commission under the centralised procedure, covering the intravenous administration of that product
August 2013	In August 2013, the Commission granted a line extension of that MA for a new subcutaneous formulation of Herceptin (Herceptin SC), a combination of trastuzumab with rHuPH20. In the MA documentation, trastuzumab is identified as the active ingredient, whereas rHuPH20 is classified as an excipient and described as a ‘novel excipient’.
Halozyme Inc.	Halozyme, the appellant in the main proceedings, is the proprietor of European patent EP 2 163 643, entitled ‘Soluble hyaluronidase glycoprotein (sHASEGP). That patent concerns an invention relating, in essence, to certain enzymes which, by degrading hyaluronic acid in the body, facilitate the dispersion and absorption of co-administered medicinal products injected subcutaneously. Recombinant human hyaluronidase PH20 (rHuPH20) is one such engineered enzyme. The claims of the basic patent refer to the use of such an enzyme in combination with an anti-cancer agent – more specifically, a monoclonal antibody – for the treatment for breast cancer
21 July 2015	Halozyme sought SPC protection across several Member States in respect of the subcutaneous formulation Herceptin SC and, more specifically, for the combination of trastuzumab and rHuPH20. In the Czech Republic, it filed an application on 21 July 2015 with the Industrial Property Office, relying on the basic patent and the above mentioned MA. In its application, Halozyme characterised rHuPH20 as an active ingredient and, accordingly, identified the ‘product’ for which protection was sought as a combination of two active ingredients, namely trastuzumab and rHuPH20.
11 January 2019 and 6 November 2020	By decision of 11 January 2019, the Industrial Property Office rejected Halozyme’s application, a decision that was subsequently upheld by its President on 6 November 2020. That office and its President found, in essence, that the conditions laid down in points (a), (b) and, as the case may be, (d) of Article 3 of the SPC Regulation were not satisfied. In that regard, they considered, first, that trastuzumab is not referred to in the claims or the description of the basic patent and, secondly, that rHuPH20 is classified as an excipient in the MA, without it having been established that it has an anti-cancer effect of its own.
13 June 2022	Halozyme challenged the decision of the President of the Industrial Property Office before Prague City Court, Czech Republic. By judgment of 13 June 2022, that court dismissed the action on the ground that rHuPH20 cannot be regarded as an ‘active ingredient’ within the meaning of Article 1(b) of the SPC Regulation. In reaching that conclusion, it observed that it did not clearly appear from the evidence before it that rHuPH20, when used in combination with trastuzumab, exerts its own pharmacological, immunological or metabolic action in the treatment for breast cancer.
	Halozyme subsequently lodged an appeal on a point of law before Supreme Administrative Court. Entertaining doubts as to the interpretation of Article 1(b) and Article 3(a) of the SPC Regulation, that court decided to stay the proceedings and to refer several questions questions to the European Court of Justice for a preliminary ruling. Question 1 is provided below. Is Article 1(b) of [the SPC Regulation] to be interpreted as meaning that a substance expressly designated as an excipient, in the authorisation for a medicinal product, cannot be regarded as an active ingredient? Six questions were referred to the CJEU. You can read all of the question in the Opinion.

A request from the European Court Of justice concerning Opinion

The Court requested that the present Opinion focus solely on the first four questions referred.

By those questions, the referring court seeks, in essence, clarification as to how to determine whether a substance may be regarded as an ‘active ingredient’ within the meaning of Article 1(b) of the SPC Regulation, and thus as forming part of a ‘product’ eligible for the grant of an SPC.

The conclusion of the Attorney General Emiliou’s Opinion

In the light of the foregoing, I propose that the Court of Justice answer the first question referred as follows:

Article 1(b) of Regulation (EC) No 469/2009 of the European Parliament and of the Council of 6 May 2009 concerning the supplementary protection certificate for medicinal products

must be interpreted as meaning that the qualification of a substance as an ‘active ingredient’ within the meaning of that provision is to be determined by reference to the classification of substances set out in the marketing authorisation relied upon in support of the application for a supplementary protection certificate. Consequently, a substance which is expressly designated as an ‘excipient’ in that marketing authorisation cannot be regarded as an ‘active ingredient’ for the purposes of that regulation.

In order to fully understand the AG Opinon, it is important to read it in its entirety. The articles in the section Further Reading below should also help you to better understand the case.

Note that the AG opinion is not binding on the court. The CJEU’s ruling is expected later in 2026.

Note also that national authorities across the European Union have reached divergent conclusions in respect of equivalent SPC applications submitted by Halozyme.
Decisions favourable to Halozymehave been adopted in Belgium, Bulgaria, Spain, Italy, Cyprus, Luxembourg, Poland and Slovenia, whereas the French, Dutch and Swedish competent authorities have rejected the application.