This shows the long-term therapeutic benefit of givosiran in patients with acute hepatic porphyria (AHP)—an orphan disease that can be life threatening. The results were presented by study investigator Eliane Sardh, MD, during a webinar hosted by Alnylam. In an interim analysis of the OLE period, givosiran, which is approved in the US and EU and marketed as GIVLAARI, demonstrated sustained efficacy and safety through 12 months of treatment, with evidence for potentially improved efficacy over time.
“Less than eight months after GIVLAARI’s first regulatory approval based on the ENVISION Phase 3 study results, we are pleased to share encouraging new data from our OLE program that we believe continue to support the sustained therapeutic benefit of this RNAi therapeutic. The improvements in daily worst pain and quality of life exploratory endpoints, and consistent safety profile, help us better understand the potential of GIVLAARI to provide ongoing and long-term benefit for patients living with AHP,” said Akin Akinc, General Manager of Givosiran at Alnylam. “We remain committed to bringing GIVLAARI to patients with AHP around the world as we pursue marketing authorizations in additional countries and territories.”
The ENVISION Phase 3 study evaluated the efficacy and safety of givosiran in patients with AHP. As previously reported and recently published in the New England Journal of Medicine, givosiran met the primary endpoint in the 6-month double-blind (DB) period, with a 74% mean reduction in the annualised rate of composite porphyria attacks (AAR) that required hospitalisation, urgent healthcare visit or intravenous hemin administration at home, and a median AAR of 1.0. Givosiran also demonstrated an acceptable safety and tolerability profile in this high unmet need indication. Upon completion of dosing in the DB period, all eligible patients (93 out of 94; 99%) enrolled in the OLE period of the trial to receive monthly givosiran at either 2.5 mg/kg or 1.25 mg/kg. A dose of 1.25 mg/kg was initially studied in some patients to generate additional data at a lower dose level; all patients enrolled in the OLE period are now in the process of transitioning to the 2.5 mg/kg dose level, due to evidence for increased efficacy at the higher dose.
“AHP is a tremendously burdensome disease, characterised by painful, often disabling attacks and chronic symptoms that can greatly impact a patient’s ability to function on a daily basis,” said Eliane Sardh, MD, Porphyria Centre Sweden, Centre for Inherited Metabolic Diseases, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden. “In the placebo-controlled period of the ENVISION Phase 3 study, givosiran showed a reduction in AAR and, based on secondary and exploratory measures, an improvement in patients’ health status, daily functioning and quality of life. These results, paired with the new long-term efficacy and safety data, provide further evidence that treatment with givosiran has the potential to significantly reduce the high burden of disease for patients and families affected by AHP.”