Alnylam Presents New Clinical Results for Givosiran at the 2019 International Congress on Porphyrins and Porphyrias

Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, announced today that the Company and its collaborators presented new clinical results at the 2019 International Congress on Porphyrins and Porphyrias (ICPP), held September 8-11, 2019 in Milan, Italy. Presentations included additional results from the ENVISION Phase 3 study and the Phase 1/2 open-label extension (OLE) study of givosiran, an investigational RNAi therapeutic targeting aminolevulinic acid synthase 1 (ALAS1) in development for the treatment of acute hepatic porphyria (AHP).

“The new results that we and our collaborators presented this week at ICPP reinforce our belief in the potential of givosiran to reduce the disease burden associated with AHP and to improve quality of life for patients,” said Akin Akinc, Ph.D., Vice President and General Manager, Givosiran Program at Alnylam. “Of note, patients in our open-label extension studies have continued to experience sustained reduction of both porphyria attacks and levels of toxic intermediates known to be causative of disease manifestations. Accordingly, we are hopeful that givosiran will continue to provide the potential for long term benefit for AHP patients.”

“AHP is a tremendously burdensome condition accompanied by disabling symptoms that have a profound impact on quality of life. To that end, the patient reported outcomes in response to givosiran treatment are highly encouraging, with patients reporting significantly less pain – a primary manifestation of this condition – less reliance on analgesic medication, improvements in their daily functioning, and ability to lead a more normal life,” said Laurent Gouya, M.D., Ph.D., Paris Diderot University, Head of Centre Français des Porphyries, investigator in ENVISION Phase 3 study. “With patients reporting a positive treatment experience and data suggesting an improved quality of life based on exploratory endpoints, I am hopeful for the AHP patient community and look forward to the continued evaluation of givosiran.”

ENVISION Phase 3 OLE Results
As of the data cut-off date of January 31, 2019, all eligible patients (N=93) from the ENVISION Phase 3 study of givosiran rolled over into the OLE phase of the study. Reduction in the composite porphyria attack rate with givosiran treatment, which had been observed in the ENVISION Phase 3 study as early as one month after dosing, was shown to be sustained with continued dosing in the OLE phase of the study. Sustained reduction in levels of aminolevulinic acid (ALA), an intermediate in the heme biosynthesis pathway believed to be the primary neurotoxic intermediate responsible for causing both porphyria attacks and ongoing symptoms in between attacks, was also observed with continued dosing. Rapid and sustained lowering of attack rate and ALA levels was also observed in placebo patients who crossed over after the six-month double blind phase of the ENVISION Phase 3 study to receive givosiran in the OLE phase of the study. Givosiran’s safety profile in the OLE phase has remained consistent with the profile observed in the double blind phase of the ENVISION study.