RNA interference therapy in acute hepatic porphyrias

Area of Science:

• Biochemistry
• Genetics
• Pharmacology

Background:

• Acute hepatic porphyrias (AHPs) are inherited disorders of heme biosynthesis.
• Attacks are triggered by factors increasing hepatic 5-aminolevulinic acid synthase 1 (ALAS1) activity, leading to neurotoxic precursor accumulation.
• Chronic complications include kidney disease and hepatocellular carcinoma risk.

Purpose of the Study:

• To evaluate the efficacy and safety of givosiran, an RNA interference therapeutic targeting ALAS1, for treating AHPs.
• To assess givosiran's impact on acute attack rates, precursor levels, and quality of life in AHP patients.

Main Methods:

• Givosiran, a small interfering RNA targeting ALAS1, was administered subcutaneously monthly.
• Clinical trials assessed changes in urinary ALA and porphobilinogen, acute attack frequency, and patient-reported outcomes.
• Safety monitoring included common side effects and laboratory parameters.

Main Results:

• Monthly givosiran administration significantly reduced hepatic ALAS1 mRNA levels.
• This led to decreased urinary ALA and porphobilinogen, and a reduction in acute attack rates.
• Quality of life was improved, with common side effects including injection site reactions and elevated liver enzymes.

Conclusions:

• Givosiran is an effective treatment for AHPs, reducing acute attacks and improving patient well-being.
• While approved, long-term data on sustained ALAS1 suppression's safety and effect on chronic complications are limited.