Extension of the term of the Eurasian patent for the combination Ceftazidime + [Avibactam] in Russia has been invalidated

Eurasian patent No. 004920 for the invention titled “Azabicyclic compounds, a process for their preparation and their use as medicinal products, in particular as antibacterial agents” was published in 2004. The patent holder is Pfizer Ireland Pharmaceuticals. The patent term was extended with respect to claims 1–7 and 13–15 until July 24, 2026, based on the marketing authorization for the medicinal product Zavicefta (active ingredients – ceftazidime + [avibactam]).

On May 22, 2025, Jodas Expoim LLC filed an opposition with the EAPO against the extension of the patent term in the territory of the Russian Federation.

Jodas Expoim’s interests in this case were represented by Zuykov and Partners.

According to the opponent, the unlawfulness of the EAPO decision lies in the fact that the extension was granted in violation of paragraph 2 of Article 1363 of the Civil Code of the Russian Federation, as enacted by Federal Law No. 231-FZ of December 18, 2006, as amended.

In particular, it was noted that claims 1–7 and 13–15 of the patent, in respect of which the term extension had been granted, do not contain a set of features characterizing Zavicefta, which is a combination of the active ingredients ceftazidime and [avibactam].

For its part, the patent holder disagreed with the opposition and submitted to the EAPO a response to the opposition and a supplement thereto. According to the patent holder, the extension was granted lawfully, since claims 1–7 and 13–15 provide patent protection for avibactam as one of the active components of Zavicefta.

The review of claims 1–7 and 13–15 revealed the following.

Independent claim 1 and dependent claims 2–6 relate to a chemical compound described by general structural formula (I), covering the compound avibactam with the formula trans-7-oxo-β-(sulfoxy)-1,6-diazabicyclo[3,2,1]octane-2-carboxamide. However, none of claims 1–6 discloses a combination of two active compounds, avibactam and ceftazidime.

Dependent claim 7 lists, as one of the group of compounds, trans-7-oxo-β-(sulfoxy)-1,6-diazabicyclo[3,2,1]octane-2-carboxamide and its salts with bases, in particular the sodium salt, which is avibactam sodium, i.e., exactly the compound that is one of the active ingredients of Zavicefta. However, this claim also does not disclose the combination of avibactam and ceftazidime.

Independent claim 13 relates to “a medicinal product comprising a product of formula (I) according to claim 1, as well as its salts with pharmaceutically acceptable acids and bases.” From this wording, it follows that patent protection is granted to a medicinal product in which one compound is selected from the group of compounds included in independent claim 1 or their salts with bases or acids. Avibactam is covered by independent claim 1. The wording of independent claim 13 does not imply that the medicinal product is a combination of active compounds where, in addition to avibactam (the product of formula (I)), another active compound is present that does not belong to the product of formula (I), in particular, ceftazidime.

Independent claim 14 relates to a medicinal product comprising a product defined in any of dependent claims 2–7, as well as its salts with pharmaceutically acceptable acids and bases.

At the same time, dependent claim 7 specifies, as one of the group of compounds, trans-7-oxo-β-(sulfoxy)-1,6-diazabicyclo[3,2,1]octane-2-carboxamide and its salts with bases, in particular the sodium salt, which is avibactam sodium, i.e., precisely the compound that is one of the active ingredients of Zavicefta. Thus, independent claim 14 in conjunction with dependent claim 7 provides legal protection for the active compound avibactam, but not for its combination with ceftazidime.

Finally, independent claim 15 relates to a pharmaceutical composition containing, as an active ingredient, at least one medicinal product according to claims 13 or 14. Such wording of independent claim 15 makes it possible to conclude that legal protection is granted to a pharmaceutical composition which, in one of its alternative embodiments, contains at least two active substances, one of which is avibactam sodium, while the other compound is selected from the group of compounds included in independent claim 1 or their salts with bases or acids.

That is, claim 15 likewise does not provide legal protection for the combination of the active ingredients avibactam and ceftazidime of the medicinal product Zavicefta.

Since marketing authorization No. LP-004289 dated May 15, 2017, based on which the decision to extend the term of Eurasian patent No. 004920 was made, was issued for the medicinal product Zavicefta, which is a combination of two active ingredients, avibactam and ceftazidime, and this authorization is relevant specifically to the combination of the two active ingredients, rather than to either of them individually.

Therefore, the EAPO Board concluded that marketing authorization No. LP-004289 dated May 15, 2017, cannot serve as a basis for extending the term of Eurasian patent No. 004920 with respect to claims 1–7 and 13–15. In view of the above, it was decided to satisfy the opposition and invalidate the extension of Pfizer’s Eurasian patent No. 004920 in the territory of the Russian Federation.