Detailed narrative
First billion-dollar product-revenue quarter, led by TTR
Alnylam delivered $1.03 billion in combined net product revenues, up 121% YoY and 4% QoQ, its first quarter above $1 billion in product sales. The TTR franchise (AMVUTTRA plus ONPATTRO) contributed $910 million, up 153% YoY and 6% QoQ, while the rare-disease portfolio added $126 million (+15% YoY).
Management framed the quarter as evidence of a differentiated, durable innovation engine, noting six Alnylam-invented medicines now collectively generate several billion dollars in annual revenue reaching hundreds of thousands of patients.
U.S. ATTR-CM launch dynamics: first-line preference deepening
One year into the ATTR-CM launch, U.S. TTR revenue grew more than 230% YoY and 9% QoQ, a $59 million sequential gain achieved despite fewer shipping weeks and insurance-reauthorization dynamics. More than 1,200 unique new U.S. prescribers have adopted AMVUTTRA since last March.
Management described a natural second-line-to-first-line evolution: new prescribers initially balance first/second line, second-line use (switch or combo from progressing stabilizer patients) normalizes over time⏳, and physician experience 'breeds' a greater proportion of first-line scripts. The business is now modestly weighted toward first line, with prescriber-base expansion cited as the key growth lever.
International launches and the Germany price reset
International TTR revenue declined $7 million QoQ but grew 35% YoY, with the sequential dip driven by a previously announced Germany price adjustment following ATTR-CM launch — the most significant international impact in Q1. Results outperformed February expectations on strength in Japan (CM launch on track with leading analogs) and PN performance across markets.
Management characterized the CM-launch repricing as a deliberate mix shift — trading a smaller, higher-priced PN segment for a much larger patient population — expected to turn net-positive for growth from Q2. Recent European CM launches were cited in Austria, the U.K., Switzerland and Italy.
Pipeline: 25+ programs and next-generation TTR
Alnylam advanced a pipeline of more than 25 clinical programs. It presented ACC data on vutrisiran (real-world adherence/persistence and a HELIOS-B diastolic-dysfunction post-hoc), initiated a Phase I of ARN-2232/ALN-2232 (first adipose-directed RNAi, targeting ACVR1, in obesity), and expanded the TRITON-CM Phase III of next-generation nucresiran by ~500 patients (1,250 to ~1,750) to mitigate low-event-rate risk given faster-than-expected enrollment and milder-disease patients. 2026 milestones include completing Capricorn 1 (mevelsiran in CAA) enrollment, initiating Alzheimer's and second-bleeding-disorder Phase II trials, and H2 readouts from ALN-6400, ALN-HTT02 and ALN-2232, with an RNA Roundtable-style webinar series starting this summer.
Financials: margin, opex and profitability
Product gross margin was 80%, down 5 points YoY on a higher average Sanofi royalty rate that resets each calendar year and rises with volume — management guided to further quarterly margin declines through the year. Non-GAAP R&D rose 39% to $335 million (Xenith, TRITON-CM/PN, plus bleeding-disorder, Huntington's and CAA programs) and non-GAAP SG&A rose 36% to $283 million on launch investment.
Non-GAAP operating income reached $339 million (>4x YoY), a third consecutive quarter of GAAP and non-GAAP profitability. Collaboration revenue was $82 million (-17% YoY, lapping a $30M milestone) and royalty revenue $49 million (+85%). Cash, equivalents and marketable securities ended at $3 billion.
Competitive landscape and generic-stabilizer positioning
Management fielded repeated questions on competitor AstraZeneca's upcoming CARDIO-TRANSFORM readout (expected later this year) and on a Pfizer settlement enabling generic tafamidis. It reiterated that Alnylam's growth outlook is not dependent on generic-stabilizer timing, citing broad first-line access (>90%), 0 out-of-pocket for most patients, >75% new-patient share in PN, and a large untreated ATTR-CM population (~200,000 U.S. patients, >80% untreated).
Management expects a positive combination readout from competitors would further validate the silencer class and pointed to its own combination label and TRITON-CM (silencer-on-stabilizer) data package as reinforcing leadership.