Why Is Alnylam Pharmaceuticals Stock Trading Lower Thursday?

Core Viewpoint - Alnylam Pharmaceuticals reported strong third-quarter earnings, but the stock is trading lower due to unmet investor expectations regarding Amvuttra sales, despite significant year-over-year growth in revenue and earnings [1][2][7]. Financial Performance - The company reported adjusted earnings of $2.90 for Q3 2025, a significant improvement from a loss of $0.50 in the same quarter last year, surpassing analyst estimates of $0.75 [2]. - Quarterly sales reached $1.25 billion, representing a 149% increase year-over-year, exceeding the consensus estimate of $977.79 million [2]. Revenue Breakdown - Total net product revenues increased by 103% (99% at constant currency), primarily driven by Amvuttra's growth due to increased patient demand, particularly among patients with ATTR amyloidosis with cardiomyopathy in the U.S. [3]. - Amvuttra sales surged by 165% to $685.30 million, while Onpattro revenue decreased by 22% to $39.07 million. Oxlumo sales increased by 31% to $52.83 million, and Givlaari sales reached $73.87 million, up 4% year-over-year [4]. Guidance and Future Outlook - Alnylam raised its fiscal 2025 sales guidance from $3.3 billion-$3.55 billion to $3.6 billion-$3.8 billion, compared to the consensus of $3.53 billion [6]. - Total TTR net product revenues (Amvuttra and Onpattro) are now expected to be $2.48 billion-$2.53 billion, an increase from the previous guidance of $2.175 billion-$2.275 billion [6]. Market Reaction - The stock experienced an 8.05% decline, trading at $442.81, attributed to high investor expectations for Amvuttra sales, which fell short of the anticipated range of $695 million to $700 million [7].