Cambridge, Massachusetts — Alnylam Pharmaceuticals reported $1.17 billion in global net product revenue for the second quarter of 2026, up 74% from the same period a year earlier, as sales of its transthyretin amyloidosis treatments continued to expand.
The RNA interference therapeutics company generated $1.03 billion in combined revenue from AMVUTTRA and ONPATTRO, an increase of 89% from the second quarter of 2025.
AMVUTTRA revenue totaled $1.01 billion, while ONPATTRO generated $18 million.
Alnylam lowered its full-year 2026 guidance for TTR net product revenue to between $4.2 billion and $4.5 billion, down from its previous forecast of $4.4 billion to $4.7 billion. The midpoint of the revised range represents growth of about 75% compared with 2025.
The company attributed the change to early commercial trends in the evolving market for transthyretin amyloid cardiomyopathy, or ATTR-CM, including a normalization in second-line patient volume after an initial period of pent-up demand.
“During the first half of 2026, we continued to meaningfully advance our business, generating over $1 billion in quarterly product revenues for the first time in our history during the first quarter and, building on that momentum, over $1 billion in TTR revenues during the second quarter,” said Yvonne Greenstreet, M.D., Chief Executive Officer of Alnylam.
Greenstreet said the results reflected the growing global reach of Alnylam’s TTR franchise and AMVUTTRA’s position as a treatment approved across the spectrum of ATTR amyloidosis.
“We have lowered our TTR product sales guidance for full-year 2026 to reflect learnings from the initial phase of our launch in the evolving ATTR-CM market, in particular the normalization of growth in second-line volume after satisfying pent-up demand from patients waiting for a new therapy,” she added.
U.S. TTR net product revenue increased by $106 million from the first quarter of 2026. Alnylam said the increase was driven by $129 million in additional demand, partially offset by an inventory impact of about $20 million and a modest decline in net pricing.
International TTR revenue increased by $14 million sequentially, primarily because of higher demand for treatments used in hereditary ATTR polyneuropathy and ATTR-CM.
Alnylam also reported combined second-quarter revenue of $142 million from its rare disease products GIVLAARI and OXLUMO, up 11% from a year earlier. GIVLAARI generated $90 million, while OXLUMO produced $52 million.
The company continued to expand the global reach of AMVUTTRA through a recent launch in Spain and an exclusive commercialization agreement with BeOne Medicines covering mainland China and Macao, subject to regulatory approval.
Alnylam also highlighted new analyses from the Phase 3 HELIOS-B trial of vutrisiran in patients with ATTR-CM. Data presented at Heart Failure 2026 showed that reductions in all-cause mortality and recurrent cardiovascular events were maintained across major patient subgroups receiving a range of heart failure therapies.
A pooled analysis representing more than 25,000 patient-years of treatment with TTR-silencing RNAi therapies also showed a consistent safety profile, according to the company.
Alnylam said it is collaborating with a large California healthcare system on the DETECT-ATTR study, which will evaluate an artificial intelligence-enabled echocardiography screening tool for cardiac amyloidosis. The study is intended to improve earlier detection of the disease in routine clinical care.
The company also outlined plans for DemonsTTRate, a prospective observational study expected to enroll more than 2,000 patients with ATTR-CM and follow them for as long as five years.
During the quarter, Alnylam initiated a Phase 2 trial of ALN-6400 in patients with von Willebrand disease and heavy menstrual bleeding. It also began a Phase 1 study of ALN-6222, an RNAi therapeutic targeting inhibin E in patients with obesity.
The company completed enrollment in the Phase 2 cAPPricorn-1 study of mivelsiran in cerebral amyloid angiopathy and began a separate Phase 2 trial in patients with Down syndrome-associated Alzheimer’s disease.
Additional Phase 1 data presented at the Alzheimer’s Association International Conference showed sustained reductions in biomarkers associated with amyloid production after treatment with mivelsiran, with no evidence of an increased risk of amyloid-related imaging abnormalities.
Alnylam also presented preclinical findings and Phase 1 study details for ALN-5288, an investigational RNAi therapy targeting tau for Alzheimer’s disease and other tauopathies.
Regeneron Pharmaceuticals, an Alnylam collaboration partner, recently announced that U.S. and European regulators accepted applications for cemdisiran in adults with generalized myasthenia gravis who test positive for anti-acetylcholine receptor antibodies. The FDA granted the application Priority Review and set a target action date in November 2026.
Alnylam also entered a strategic collaboration with Inceptive Nucleics to apply artificial intelligence and foundation models to RNAi drug discovery. The company expanded its partnership with Komodo Health to deploy the Marmot analytics platform across additional business functions.
Benjamin Franklin Cravatt III, Ph.D., was appointed to Alnylam’s Board of Directors during the period.
