Agreement to differ

FDA’s approval of Alnylam’s Onpattro marks the start of a showdown in the Orphan disease hATTR amyloidosis, with Akcea’s Tegsedi likely coming to the U.S. market in less than two months. Alnylam has used its first mover advantage to set the stage with a novel outcomes-based payment model that Akcea will have to at least match to gain a competitive foothold for reaching patients.

That the drugs notch several “firsts” is not a surprise. The Aug. 10 announcement made Alnylam Pharmaceuticals Inc.’s Onpattro patisiran the first RNAi drug to be approved -- a breakthrough 20 years in the making...