(April 4, 2018, 11:27 AM EDT) -- ALEXANDRIA, Va. — In an April 2 petition for post-grant review (PGR) filed with the Patent Trial and Appeal Board, a pharmaceutical company warns that allowing small interfering ribonucleic acid (siRNA) molecules to be patented could create a risk of “blocking or delaying life-extending, disease modifying technologies” (Alnylam Pharmaceuticals Inc. v. Silence Therapeutics GmbH, No. PGR2018-00059, PTAB)....