Stock slide continues for Alnylam, Ionis after Pfizer readout

Shares of Alnylam Pharmaceuticals Inc. (NASDAQ:ALNY) and Ionis Pharmaceuticals Inc. (NASDAQ:IONS) continued to fall Monday, following data released March 29 showing that tafamidis meglumine from Pfizer Inc. (NYSE:PFE) met the primary endpoint in a Phase III study to treat transthyretin (TTR) cardiomyopathy. Alnylam and Ionis each have compounds targeting TTR under regulatory review.

Alnylam shed $17.92 (15%) to $101.18 on Monday, and has lost $2.9 billion in market cap since markets closed March 28. Ionis slipped $1.96 to $42.12, losing about $478 million in value over the same period. U.S. markets were closed on Friday. The stocks fell amid a broader sell-off in the markets on Monday, with the NASDAQ Biotechnology Index (NBI) falling 4%, the NYSE Arca Biotechnology Index (BTK) dropping 5% and the NASDAQ Composite off 3%...