Alnylam to seek approval for second RNAi drug

Alnylam thinks it has strong enough clinical data for its gene-silencing drug for rare disease acute hepatic porphyria (AHP), and plans to move ahead with regulatory filings in the US and Europe. The US biotech made a bit of biotech history last August after getting the first-ever FDA approval for a gene-silencing drug based on RNA interference (RNAi) technology – Onpattro (patisiran) for hereditary transthyretin-mediated amyloidosis (hATTR) �� and now plans to add to its stable with AHP therapy givosiran. If it gets approved, givosiran would be a much-needed new therapeutic option for patients with AHP, a genetic disease caused by a deficiency in one of the enzymes used to synthesize haem in the liver that causes a toxic build-up of metabolites and in turn severe pain, muscle weakness, and nerve damage. Alnylam had originally hoped to file givosiran on the strength of biomarker results from the phase III ENVISION study last year but held off for the final readout – released yesterday – on clinical outcomes after discussions with the FDA. At the time, analysts said the short delay would not have any impact on givosiran’s approvability or commercial potential.