US FDA nod for first acute hepatic porphyria treatment

Shares of RNAi therapeutics company Alnylam Pharmaceuticals (Nasdaq: ALNY) closed up 10.5% at $108.21 on Wednesday, after the company revealed earlier than expected approval for its rare genetic disease candidate, and with a broader label than was anticipated.

The US Food and Drug Administration granted approval to Givlaari (givosiran) for the treatment of adult patients with acute hepatic porphyria, a rare genetic disorder resulting in the build-up of toxic porphyrin molecules which are formed during the production of heme (which helps bind oxygen in the blood).

The FDA approval of Alnylam’s Givlaari was received in less than four months after acceptance of the New Drug Application (NDA) and was based on positive results from the ENVISION Phase III study – a global study and the largest ever interventional study conducted in AHP, which showed that AHP patients on Givlaari experienced 70% fewer porphyria attacks – requiring hospitalization, urgent health care visits, or IV hemin administration at home – compared to the placebo arm.