Dosage Regimen Patent Found Obvious

Mylan have been successful in challenging the validity of a dosage regimen patent.

May 2014

In the case, Generics (UK) Ltd (t/a Mylan) v Richter Gedeon Vegyeszeti Gyar RT [2014] EWHC 1666 (Pat) (22 May 2014), Mylan brought a claim for a declaration that Richter’s European Patent (UK) no. 1 448 207 B1 entitled "Dosage Regimen and Pharmaceutical Composition for Emergency Contraception" ("the Patent") was invalid and should be revoked. The Patent concerned a dosage regimen for use of levonorgestrel as a method of emergency contraception. 

The regimen for which the Patent was claimed was for use of a single dose of levonorgestrel of 1.5 mg taken within 72 hours of sexual intercourse. The previous dosage regimen required two doses of 750 µg taken 12 hours apart.

The grounds of invalidity relied on were (1) obviousness, and (2) insufficiency.

For its obviousness case, Mylan relied upon common general knowledge ("CGK") and the publication in late 2000 of a report discussing interim results of a Dr von Hertzen's research for the WHO regarding the effectiveness of a regimen involving a single dose of 1.5 mg of levonorgestrel, as compared (in particular) with the two-dose regimen which was in widespread use. The report was by Professor Stephen R. Killick, the Editor-in-Chief of Gynaecology Forum, in a special issue of that journal to report the highlights of the XVI FIGO World Congress of Gynecology and Obstetrics in September 2000 in Washington DC, USA ("the Killick article").

In the article, Professor Killick reported on a presentation by three speakers, who had been involved in extensive studies organised by the WHO, who summarised work of the previous 10 years.  At three places in the article, Professor Killick referred in error to the research study being in relation to a regimen involving a single dose of 1.5 g of levonorgestrel (rather than 1.5 mg). It was considered that this would have been appreciated to be an obvious mistake by a clinician skilled in the art relating to emergency contraception and that such a clinician would have made further enquiries as to the true dosage.

The Killick article included a table comparing the results to the date of the presentation from blind trials of three emergency contraception treatments: two doses of levonorgestrel, a single, larger dose of levonorgestrel and a single dose of mifepristone.  In reference to the table, it was stated that “The suggested summary from the floor was that a single dose of 1.5 g levonorgestrel was the preferred oral method because there was no difference between groups in the most recent WHO study, but Dr Glasier advised great caution with this assumption as the trial was still incomplete. The last few subjects could alter the data and it was wrong to try to guess which group was which, however tempting this might be."

Judge Sales applied the 4 step Pozzoli test for obviousness.  He considered that the additional research work (finalising the study which was already well advanced as reported at the time of the presentation in September 2000) and additional information (confirmation of the preliminary findings presented in September 2000) were “not of the character or extent that one could reasonably describe them as a significant additional contribution to human knowledge such that one would expect them to attract protection in the form of a patent monopoly of exploitation”.

“The possibility of using the single dose regimen involving levonorgestrel for emergency contraception had already been substantively revealed and attested by the extant research findings reported in September 2000 as an obvious likely way forward in the field of emergency contraception, notwithstanding the caveat regarding the need to finish the study mentioned at the end of the Killick article.

 For these reasons it was judged that the challenge to the validity of the Patent on the ground of obviousness should succeed and the Patent found invalid.  The insufficiency challenge did not need to be considered.  

This update was prepared by Martyn Fish: Partner of HGF Law, Leeds  Tel:  +44(0) 113 233 0148

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