In 2019, Alnylam Pharmaceuticals received FDA approval for Givlaari, the first RNAi therapy for patients with acute hepatic porphyria. Although some were initially worried about the therapy’s safety and efficacy, open-label Givlaari data from the Phase 3 Envision study shows positive results. Read the full results on Alnylam’s website.

Acute Hepatic Porphyria

To understand acute hepatic porphyria, you need to first understand its nuances. Acute hepatic porphyria is part of a group of 8 rare, inherited metabolic disorders. People with porphyria don’t have enough enzymes to produce heme, a blood pigment in hemoglobin that helps transport oxygen throughout the body. As a result, porphyrins (chemicals) accumulate in the cell and reduce oxygen.

Hepatic porphyria occurs when patients lack enzymes in their liver. There are a few subtypes of acute hepatic porphyria, including acute intermittent porphyria, variagate porphyria, hereditary coproporphyria, and hereditary deficit of delta-aminolevulinic acid dehydratase.

When experiencing an “attack,” patients may present with:

• Skin lesions, blistering, and inflammation after exposure to light
• Muscle weakness and convulsions
• Irritability or anxiety
• Auditory and visual hallucinations
• Confusion
• Intense abdominal cramping

Attacks are often brought on from external triggers such as stress, alcohol, infections, or a poor diet. However, they can also result from hormonal changes. Learn more about hepatic porphyria here.

Givlaari Data

In fact, Givlaari effects, and attack reduction, were sustained over a 1-year period. Patients receiving a higher dose had better outcomes. Additionally, Givlaari seemed to be safe and well-tolerated, without many adverse reactions.