Investors weren't in a very forgiving mood with commercial-stage biotech Alnylam Pharmaceuticals (ALNY 1.52%). After the company reported its latest set of quarterly results, those folks showed their displeasure by trading the stock down by more than 4% that trading session.
Amvuttra powers revenue growth
Alnylam took the wraps off its fourth-quarter and full-year 2025 results before market open. These revealed that the company's revenue nearly doubled on a year-over-year basis, landing at just under $1.1 billion.
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Net income not in accordance with generally accepted accounting principles (GAAP) ballooned over that one-year stretch. It was nearly $169.8 million, or $1.25 per share, against the year-ago profit of slightly over $8 million.
With those numbers, Alnylam edged past the $1.19 per share consensus analyst estimate for non-GAAP (adjusted) profitability. On the other hand, it missed the pundits' $1.15 billion revenue forecast.
The company's key top-line driver was Amvuttra, the net sales of which were responsible for the bulk (83%) of its net product revenue for the period.
In March 2025, Amvuttra -- an RNAi medication that was first approved by the Food and Drug Administration (FDA) in 2022 -- was given the nod by the regulator for the treatment of transthyretin amyloid cardiomyopathy (ATTR-CM). This is a disorder in which protein deposits can lead to a thickening of the heart.

NASDAQ: ALNY
Key Data Points
Victim of success
For the entirety of 2026, Alnylam is guiding for total revenue of $5.3 billion to $5.8 billion; the analyst consensus of $5.55 billion falls within this range. It did not provide a net income forecast.
Alnylam is enjoying robust sales with Amvuttra's new(ish) indication, so I feel that much of the investor reaction was due to extremely optimistic expectations. I'd be more bullish on the stock, as take-up has been quick, and the product is clearly resonating with clinicians and patients. I feel it has plenty of room to run at this stage.





