N. Engl. J. Med. 382, 2289–2301 (2020)

A phase 3 trial of givosiran, an RNA-interference therapy, for acute intermittent porphyria resulted in a reduced rate of porphyria attacks.

Acute hepatic porphyria is a set of rare diseases in which porphyrins build up, which results in neurotoxic effects. Intermittent hepatic poryphyria is the most common form and is caused by upregulation of hepatic delta-aminolevulinic acid synthase 1, which results in attacks that include symptoms such as abdominal pain, muscle weakness and neuropathy. Treatment options are limited; however, givosiran has shown promise.

In a double-blind, placebo-controlled, phase 3 trial of 94 patients with acute hepatic porphyria, those receiving givosiran had a significantly lower rate of attacks, in addition to improvements in other disease-associated symptoms.