Shares of Alnylam Pharmaceuticals rose by over 32%, the company’s largest single-day gain in nearly two years, after announcing its drug vutrisiran helped reduce the number of deaths and cardiovascular events in a study of patients with a rare heart disease.
It’s the largest single-day gain for the company in nearly two years.
Alnylam shares jumped to $225.35 as of Monday morning, following an earlier surge in premarket trading.
This is the largest single-day gain for the company since August 3, 2022, when shares rose by over 49% to $210 after Alnylam announced its nerve disease drug improved the walking ability in patients with a form of heart disease.
Alnylam said Monday that vutrisiran, an experimental drug for treating a rare condition called transthyretin amyloid cardiomyopathy (ATTR-CM), reduced deaths by all causes and heart-related events by 33%, compared to 28% among patients who received Pfizer’s Food and Drug Administration-approved drug for treating ATTR-CM and a placebo.
Trial patients received either vutrisiran or a placebo once every three months for as long as three years.
The trial resulted in statistically significant improvements in reducing disease progression, including how far patients could walk in six minutes, Alnylam said.
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Alnylam plans to apply for regulatory approval of vutrisiran later this year.
Up to 300,000. That’s how many people are affected by ATTR-CM worldwide, according to Alnylam’s estimates. Testing for ATTR-CM is difficult, though more patients at risk of cardiovascular failure are being screened as technology advances, according to a 2023 study, which estimates between 5,000 and 7,000 new cases are diagnosed each year in the U.S.
ATTR-CM restricts the function of the heart’s muscles because of the accumulation of irregular proteins. Only Pfizer’s drug—sold as Vyndaqel and Vyndamax—is available for treating the disease, though other pharmaceutical companies like BridgeBio and Ionis Pharmaceuticals are developing treatment options. Shares of BridgeBio dropped about 17% Monday morning.