ENVISION: A Study to Evaluate the Efficacy and Safety of Givosiran (ALN-AS1) in Patients With Acute Hepatic Porphyrias (AHP)

Inclusion Criteria:

- ≥ 12 years of age

- Diagnosed with Acute Hepatic Porphyria (Acute Intermittent Porphyria, Hereditary
Corproporhyria, Variegate Porphyria, ALA dehydratase deficient porphyria)

- Elevated urinary or plasma PBG or ALA values within the past year,

- Have active disease, with at least 2 documented porphyria attacks within the last 6
months

- Willing to discontinue or not initiate the use of prophylactic hemin throughout the
study.

- Women of child bearing potential must have a negative serum pregnancy test, not be
nursing, and use acceptable contraception

Exclusion Criteria:

- Clinically significant abnormal laboratory results

- Anticipated liver transplantation

- History of multiple drug allergies or intolerance to subcutaneous injections

- Active HIV, hepatitis C virus, or hepatitis B virus infection(s)

- History of recurrent pancreatitis