Isis Pharmaceuticals, Inc. announced today that it has earned an $18 million milestone payment from GlaxoSmithKline related to the advancement of the Phase 2/3 study of ISIS-TTRRx in patients with familial amyloid polyneuropathy . "ISIS-TTRRx is the most advanced drug in our collaboration with GSK, and aside from KYNAMRO, it is also the furthest advanced in our late-stage clinical pipeline.