Alnylam's RNAi drug candidate shows promise

Alnylam released new date late Friday evening, expanding on how its experimental gene-silencing RNAi drug, givosiran, affects patients with acute intermittent porphyria, a rare disease that can cause acute and sometimes life-threatening attacks.

The drug shows more promise for some patients than it does for others: Half the patients had none of the attacks characteristic of the disease. Patients, overall, saw a 74% reduction of symptoms, which include severe pain, gastrointestinal distress, and breathing problems.

Alnylam views this as a win for its Nobel-winning technology. But some say the drug might only have value in patients with the most severe forms of acute intermittent porphyria.