Alnylam up on patisiran Phase II extension data

Alnylam Pharmaceuticals Inc. (NASDAQ:ALNY) jumped $13.83 (19%) to $86.68 after six-month data from a Phase II study of patisiran ( ALN-TTR02) suggested the compound may have halted progression of transthyretin (TTR)-mediated amyloidosis (ATTR) in patients with familial amyloidotic polyneuropathy (FAP). Alnylam gained more than $1 billion in market cap with the move.

Preliminary data from the ongoing open-label extension study showed a mean 0.95 point decrease in modified Neuropathy Impairment Score (mNIS+7) at six months. Alnylam estimated that untreated FAP patients with similar baseline characteristics typically experience a seven- to 10-point increase in mNIS+7 at the six month mark, based on historical data. ...