Alnylam Pharmaceuticals lowered its full-year 2026 sales guidance, citing a normalization of second-line Amvuttra demand after an initial surge. This guidance cut, despite beating Q2 adjusted EPS, led to a significant stock plunge, reflecting investor concerns about future growth in the ATTR-CM market.
Alnylam Pharmaceuticals announced a reduction in its fiscal 2026 sales guidance, primarily due to a slowdown in the growth of second-line Amvuttra demand in the ATTR-CM market, which had previously seen pent-up demand. This news, despite a Q2 adjusted EPS beat, caused Alnylam's stock to plummet, indicating investor concern over the company's future revenue trajectory and the competitive landscape. The broader ATTR-CM market is also under scrutiny following the recent failure of Ionis and AstraZeneca's eplontersen in a Phase 3 trial, which could impact other developers like Alnylam, though Alnylam remains confident in its Nucresiran program. Short-term, ALNY faces significant selling pressure; long-term, its ability to differentiate Nucresiran and capture market share will be crucial. The key risk for traders is continued downward pressure on ALNY and potential ripple effects on other ATTR-CM developers.