Alnylam's second quarter delivered one of the strongest profit quarters in its history - the company reached GAAP profitability for the first time only in 2025 - and the market reacted as if it had disappointed. Total revenue climbed 67% to $1.29 billion, net product revenue passed the billion-dollar mark for a straight second quarter, and GAAP earnings swung to a $1.21 diluted per-share profit from a $0.55 loss a year earlier - the first time the company has printed a GAAP profit at this scale. Yet the shares touched a 52-week low near $205 on the July 30 print before recovering to about $224. The reason is guidance. Management trimmed its full-year TTR product-revenue forecast to a range of $4.2 billion to $4.5 billion from $4.4 billion to $4.7 billion, explaining that growth in second-line patients - those progressing on stabilizer therapy who had been waiting for a new option - has "normalized" after the initial burst of pent-up demand that flattered the franchise's launch. The stock's reaction is the market pricing that read-through: a superb quarter whose growth rate the company itself is now tempering.
The quarter and the cut are not contradictory; they describe the same launch at two different moments. The TTR franchise, led by AMVUTTRA, grew 89% to just over $1.0 billion in the quarter alone - AMVUTTRA alone rose 106% to $1.01 billion - as the drug established itself as the only approved therapy for the full spectrum of transthyretin amyloidosis, polyneuropathy and cardiomyopathy. That is a genuinely enormous product. What changed is not the demand base but its shape: after patients who had accumulated on stabilizer therapy were converted, new second-line starts settled back to a normal pace. The financials beat every prior Alnylam print - including $318 million of non-GAAP operating income, up 233% - while the forward forecast conceded that the explosive early phase outsizes the durable trajectory. Investors at roughly $30 billion of market value are now paying a large-cap price for a company whose question has shifted from "can it reach profitability" to "how fast does the ATTR-CM launch compound now that the easy conversions are done."