In its first commercial quarter for ATTR-cardiomyopathy, Alnylam’s Amvuttra reached roughly 1,400 patients and made more than $490 million.
In its first commercial quarter in the ATTR-CM market, Alnylam’s siRNA therapy Amvuttra carried the biotech’s revenues to a comfortable beat over consensus estimates and gave the company enough confidence to substantially raise its full-year 2025 guidance.
Amvuttra made $491.9 million in the quarter, a 112% increase from the same period last year. Those sales are from both of its indications: polyneuropathy of hereditary transthyretin-mediated amyloidosis (ATTR), for which Amvuttra was initially approved in 2022, and ATTR-cardiomyopathy (CM), its newest indication that was granted in March.
Some 1,400 ATTR-CM patients were on Amvuttra at the end of its first quarter of availability for the condition, according to Alnylam’s second-quarter earnings report on Thursday.
Writing to investors on Thursday, analysts at Stifel called Amvuttra’s Q2 performance “very impressive,” noting that its total revenues deliver a “significant beat versus Street expectations” of $342 million. Investors also seemed impressed by Alnylam’s execution of Amvuttra’s ATTR-CM launch. The company was up more than 15% at market close.
“Even in the backdrop of high Street expectations, Amvuttra performance’s here clearly aligns with the bull case and makes us more optimistic on peak sales potential,” Stifel added.
BMO Capital Markets wrote in their own note late Thursday that Amvuttra’s sales “reflect strong patient demand,” given a growing prescriber base, robust uptake without price adjustments and apparent penetration of the drug into first and second line settings.Given Amvuttra’s strong launch, Alnylam on Thursday lifted its full-year sales guidance from $2.05 billion to $2.25 billion, as previously forecasted, to $2.65 billion to $2.8 billion, a 27% increase. The company also now expects the growth of its net product sales to hit 59% to 68%, year-on-year at constant exchange rates, versus its prior guidance of 26% to 39%.
The biotech made $773.7 million in Q2, representing a 17% year-on-year growth and a substantial beat over the consensus revenue forecast of $651 million.
In the ATTR-CM market, Alnylam is facing off against Pfizer, which owns the transthyretin stabilizer tafamidis. That drug was approved in 2019 as Vyndaqel and Vyndamax and has used its first-to-market advantage well: In 2024, Pfizer logged $5.45 billion in sales for its tafamidis products, a hefty 60% year-on-year growth.
Pfizer remains confident that it can protect its slice of the ATTR-CM market, with CEO Albert Bourla telling investors at a TD Cowen event in March that as long as treatment is going well, doctors “will never switch a patient to something different.” Pfizer “will maintain a lion’s market share” for new ATTR-CM prescriptions, Bourla added, noting the pharma’s extensive network and deep understanding of physician prescription patterns.
Also competing with Alnylam is BrdigeBio, which owns Attruby, another transthyretin stabilizer. Since its approval in November 2024, Attruby had delivered 1,028 unique prescriptions as of Feb. 17. As of April 25, more than 2,000 unique patients had been treated with Attruby, resulting in $36.7 million in sales during the drug’s first commercial quarter.
