Alnylam shares rise on expanded heart drug approval

March 21 (Reuters) - Alnylam Pharmaceuticals' ALNY.O shares rose about 7% before the bell on Friday following U.S. approval for its drug for a rare and deadly heart disease, securing an entry into a market dominated by Pfizer's PFE.N blockbuster Vyndaqel.

The injectable drug, Amvuttra, was approved to treat adult patients with ATTR-CM, in which faulty transthyretin proteins accumulate in the heart, potentially causing the organ to fail.

The green light also makes it the first drug capable of addressing both forms of the disease after it was approved in 2022 to treat nerve damage related to the disease.

Amvuttra's approval "checks the box" for convenient, less frequent dosing, which will eventually underpin broader commercial opportunities, said Jefferies analyst Maury Raycroft.

The drug also reduces the production of the disease-causing protein at the source, unlike Pfizer's Vyndaqel and BridgeBio's BBIO.O Attruby, which stabilize transthyretin production.

Amvuttra's label specifies that the treatment can reduce hospitalizations or death resulting from heart complications, as well as urgent visits for heart failure.

"The differentiated indication sets it off to a great launch," said BMO Capital Markets analyst Kostas Biliouris.

Needham analyst Joseph Stringer estimated $5.2 billion in sales of Amvuttra by 2030.

The drugmaker is also maintaining the list price of $119,351 per prefilled syringe for the drug, which is given once every three months, a premium to rivals.