Alnylam shares tumble to $250 after cutting full-year revenue guidance for its TTR franchise

Alnylam Pharmaceuticals saw its share price slide to about $250 after the company lowered its full-year revenue outlook for its transthyretin (TTR) franchise. The guidance cut, announced in July, followed a second‑quarter sales shortfall for its TTR silencer Amvuttra.

The company reduced its full-year revenue target by roughly $200 million, prompting investors to question the product’s growth potential in a market where small‑molecule TTR stabilizers from BridgeBio Pharma and Pfizer are already established. Analysts noted that the miss raised doubts about peak sales and could create a near‑term credibility overhang.

Despite the setback, several analysts remain cautiously optimistic about Alnylam’s longer‑term commercial prospects, citing ongoing tailwinds for RNAi therapeutics and the company’s broader pipeline. However, they caution that the guidance revision may temper enthusiasm until the TTR franchise demonstrates more consistent performance.