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Alnylam Stock Plunges 25% on Weak Demand Outlook
Why did Alnylam stock plunge 25%?
Alnylam (ALNY) stock fell 25% to $174 on Thursday after the drugmaker gave a weak demand outlook for heart drug Amvuttra and warned Medicare changes may hurt sales.
Key numbers
| Alnylam share price | $174.00-25.1% in one day |
|---|---|
| Q3 net product revenue | $1.29B+52% YoY |
| Amvuttra Q3 revenue | $1.13B+65% YoY |
| 2026 revenue forecast | $4.7B–$5.1BReiterated |
| Stifel price target | $225Cut from $318 |
What happened
Alnylam (ALNY) stock fell 25% to $174 on Thursday after the drugmaker gave a weak demand outlook for heart drug Amvuttra and warned Medicare changes may hurt sales. Third-quarter sales of its medicines rose 52% from a year earlier to $1.29 billion, yet management said it is not satisfied with how fast new patients are starting treatment. Tighter Medicare Advantage rules limit patient access, and a proposed rule on a hospital drug-discount program (340B) adds uncertainty. Alnylam kept its 2026 sales forecast of $4.7–5.1 billion.
Why it matters
Alnylam depends on Amvuttra, a treatment for a serious heart condition, as its main source of growth. Sales are still rising fast, but investors now worry that insurer rules and hospital pricing changes could slow how many patients get the drug. A 25% drop in one day shows how much of the company's value rested on rapid growth continuing.
Who this affects
- MarketbearishMedium impact
- Biotech investors saw a sharp one-day loss in a major name.
- CompanybearishHigh impact
- Alnylam shareholders lost a quarter of value; growth doubts rise.
- CompetitorsmixedLow impact
- Pfizer and BridgeBio barely moved; Ionis slipped about 1%.
- IndustrybearishMedium impact
- Drugmakers face tougher Medicare coverage and discount-program rules.
Alnylam vs BridgeBio, Ionis, Pfizer
How we got here
Alnylam reports Q3 sales up 52% and keeps its 2026 forecast
Company expands heart-drug trial to 2,250 patients from about 1,750
Stifel cuts Alnylam to Hold from Buy, lowers price target to $225
Shares close at $174.00, down 25.1%, near a 52-week low
What to watch
- Whether heart-drug (TTR) sales land at the low end of the $4.2–4.5B forecastQ4 2026
- Final version of the proposed federal 340B hospital drug-discount ruleQ4 2026
- Whether more Medicare Advantage plans require other treatments before AmvuttraQ4 2026
Educational content only. Not investment advice.
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