Alnylam ends revusiran development due to safety concerns

Alnylam Pharmaceuticals Inc. (NASDAQ:ALNY) plummeted $29.40 (42%) to $40.90 in early after-hours trading Wednesday after it said it will discontinue development of revusiran ( ALN-TTRsc) due to an "imbalance of mortality" in the Phase III ENDEAVOUR trial. The placebo-controlled study evaluated the RNAi candidate to treat familial amyloidotic cardiomyopathy (FAC), a form of transthyretin (TTR)-mediated amyloidosis (ATTR).

The company requested a review of the ENDEAVOUR data following four reports of new onset and worsening peripheral neuropathy in a Phase II open-label extension study of revusiran. Alnylam said a data monitoring committee (DMC) did not find evidence of drug-related neuropathy in ENDEAVOUR, but told the company revusiran's benefit-risk profile "no longer supported continued dosing." Alnylam said it identified the mortality imbalance after its own review of the data following the DMC's recommendation. ...