Merck’s patent involved the use of alendronate in the manufacture of a medicament for treating osteoporosis in humans, in need of such treatment, wherein said medicament is orally administered to said human as a unit dosage comprising about 70mg of the alendronate compound, on the basis of alendronic acid active weight, according to a continuous schedule with a dosing interval of once per week.

Use of alendronate for the treatment of osteoporosis was well known, and it was a widely prescribed drug, but with a different dose of 10 mg per day. The Merck patent therefore was for a new dosage of 70 mg once a week.

Merck alleged that the weekly dose claimed made possible to reduce the side effects (including in the gastro-oesophageal area) compared to the daily dosage known.

17 pharmaceutical companies, among which BIOGARAN, have filed opposition against this patent.

The patent was revoked in the first instance for lack of inventive step, in view of a publication of the prior art which suggested weekly doses of 40 or 80 mg of alendronate.

Merck filed an appeal against the first instance decision.

The Board of Appeal of the EPO upheld the revocation decision made by the Opposition Division, but on other grounds, holding that the claimed subject matter went beyond the content of the parent application as filed (the MERCK patent being from a divisional application).

Indeed, Merck added on appeal the further restriction on its main claim, that alendronate was administered in tablet form.

In its decision, the Board of Appeal has applied particularly strict by the provisions of Article 123 (2) EPC (or Article 76 (1) EPC for a divisional application), and held that the claims limited by Merck on appeal, limited to the administration of alendronate in tablets, violated these provisions: indeed, in the application as filed, the tablets were disclosed either in a list of galenic forms (powders, capsules , syrups, ...) or in the examples but again as an alternative to the liquid form.

The tablets were not disclosed in the original application as the preferred form of administration, and the choice of this form, together with the particular dosage (70 mg once a week) and the specific treatment of osteoporosis led, according to the Board, to a specific treatment not disclosed as such in the parent application as filed.

Following the revocation of the patent, Merck filed a petition for review before the Enlarged Board of Appeal of the EPO, alleging that, during the hearing before the Board of Appeal, its right to be heard had been violated. This request was rejected by the Enlarged Board of Appeal, as manifestly unfounded.