Merck & Co Inc announced that the Opposition Division of the European Patent Office (EPO) has rendered an oral decision to revoke Merck's patent in Europe that covers Fosamax Once Weekly (alendronate). The Opposition Division typically provides the written reasoning within two months following an oral decision.

Merck disagrees with the decision and intends to appeal, pending the formal written notification from the EPO. If the decision is reversed on appeal, Merck's patent for Fosamax Once Weekly will expire in 2018. Based on other patents, Fosamax is protected in most major European markets until at least 2007, a release from Merck said.