FDA Approves First Acute Hepatic Porphyria Drug

The US Food and Drug Administration (FDA) has approved givosiran (Givlaari) for the treatment of adult patients with acute hepatic porphyria.

The indication makes the Alnylam Pharmaceuticals therapy the first approved to treat the genetic disorder which results in the buildup of toxic porphyrin molecules. The molecules are formed during heme production.

As Richard Pazdur, MD, director of FDA's Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA's Center for Drug Evaluation and Research, noted, the disease can cause severe painful and paralyzing acute attacks which can result in respiratory failure, seizures, and mental status change.

“These attacks occur suddenly and can produce permanent neurological damage and death,” Pazdur said in a statement.

Givorsiran’s approval was based on the findings of a clinical trial assessing the drug versus placebo in 94 patients with acute hepatic porphyria. Investigators gauged the therapy’s performance based on the rate of porphyria attacks that resulted in hospitalization, urgent health care visits, or at-home intravenous hemin infusion.

Patients administered givorsiran reported 70% fewer porphyria attacks compared to patients on placebo. Common adverse events among patients on therapy included nausea and injection site reactions.

Prescribing physicians are advised to monitor patients for anaphylactic reaction and renal function issues, and to test patient liver function prior to and periodically during treatment.

The therapy was previously granted Breakthrough Therapy, Priority Review, and Orphan Drug designation.