Alnylam shares fall on Europe patent dispute loss

NEW YORK—Shares of Alnylam Pharmaceuticals Inc. fell Friday after the company said it lost a challenge in Europe on a key patent which covered certain areas of its gene-silencing technology.

The stock fell 37 cents to $28.96 Friday.

In a statement, Cambridge, Mass.-based Alnylam said claims on the "Glover" patent were overturned by the Opposition Division of the European Patent Office. The patent is licensed from Cancer Research Technology Ltd. and Alnylam said it plans to appeal the decision.

"As is well known, the European patent process is lengthy, often involving opposition and appeal procedures that result in varied outcomes, and we consider this outcome just one step for our Glover patent," the company said.

The decision, Alnylam added, does not alter the position of the company's intellectual property for developing and commercializing RNAi therapeutics, nor does it impact any ongoing business development discussions. The patent is one of 11 held by Alnylam.

The goal of gene-silencing, or RNA-based, treatments is to turn off -- or "silence" -- the gene at the root of a medical condition, treating the affliction at a genetic level.

In a separate statement, London-based Silence Therapeutics said it successfully challenged Alnylam's patent. The company also develops RNAi technology.

"The Glover patent was arguably Alnylam's broadest patent and the successful opposition represents an important victory for us in allowing us to maintain our freedom to operate," said Jeff Vick, chief executive of Silence Therapeutics.