Alnylam, Ionis fall as heart-drug data raise doubts over combination treatment

Pfizer

28/08/2026 13:43

** Shares of Alnylam Pharmaceuticals ALNY.O fall 5.3% to $224, while those of Ionis Pharmaceuticals IONS.O fall 1.3% to $61.62 in premarket trading
** Detailed data presented at the ESC Congress showed AstraZeneca AZN.L and Ionis' experimental drug eplontersen provided no added benefit in patients already taking Pfizer's PFE.N tafamidis for a deadly heart condition caused by abnormal protein buildup
** The overall study missed its main goal of reducing cardiovascular deaths and recurring heart problems, as previously disclosed in July, although eplontersen showed a possible benefit when used alone
** RBC says the findings weaken the case for seeking approval of eplontersen for the heart condition, weighing on Ionis shares
** Stifel says the results raise concerns about Alnylam's late-stage nucresiran trial because many patients are likely receiving tafamidis, and may prompt the company to focus more on nucresiran used alone
** Stifel expects little impact on sales of Alnylam's approved drug Amvuttra, as few patients currently use it with tafamidis
** As of last close, ALNY down 40.5%, IONS down 21.1% YTD 

 (Reporting by Sahil Pandey and Kunal Das in Bengaluru)
 ((Sahil.Pandey@thomsonreuters.com))