NEW YORK, (GenomeWeb News) - The European Patent Office narrowed the scope of the Kreutzer-Limmer RNAi patent claim after a number of companies objected, Sirna Therapeutics, one of the objecters, said today.

The patent, which is owned by RNAi drug company Alnylam, now only covers methods of making and using double-stranded RNA with lengths and structures of limited use as RNAi-based therapeutics, according to Sirna. The decision will also substantially limit the commercial utility of that patent.