RNA-targeted therapy company Ionis Pharmaceuticals Inc (Nasdaq:IONS) on Tuesday declared positive topline results from a 35-week interim analysis of the Phase 3 NEURO-TTRansform study of eplontersen in patients with hereditary transthyretin-mediated amyloid polyneuropathy (ATTRv-PN), a severe, progressive and life-threatening disease caused by the abnormal formation of the transthyretin (TTR) protein and aggregation of TTR amyloid deposits in various tissues and organs throughout the body, including in peripheral nerves, the heart and intestinal tract.

Eplontersen is an investigational antisense medicine that uses Ionis' advanced LIgand-Conjugated Antisense, or LICA, technology designed to inhibit the production of the TTR protein at its source. The drug is being jointly developed and commercialised as part of a global agreement between Ionis and pharmaceutical company AstraZeneca plc (STO:AZN) (LON:AZN) (Nasdaq:AZN) in the United States. It will be developed and commercialised in the rest of the world by AstraZeneca (with the exception of Latin America).

According to Ionis, eplontersen demonstrated a statistically significant and clinically meaningful change from baseline for the co-primary endpoints of percent change in serum TTR concentration and the modified Neuropathy Impairment Score +7 (mNIS+7), a measure of neuropathic disease progression, versus the historical placebo group. It also met its key secondary endpoint of change from baseline in the Norfolk Quality of Life Questionnaire-Diabetic Neuropathy (Norfolk QoL-DN), showing treatment with eplontersen significantly improved patient-reported quality of life versus the historical placebo group.

The study showed that eplontersen demonstrated a favourable safety and tolerability profile with no specific concerns. Based on these results, the companies will seek regulatory approval for eplontersen for ATTRv-PN and plan to file a new drug application with the US Food and Drug Administration this year.

Eplontersen has been granted Orphan Drug Designation in the US. It is also currently being evaluated in the Phase 3 CARDIO-TTRansform study for amyloid transthyretin cardiomyopathy (ATTR-CM), a systemic, progressive and fatal condition that leads to progressive heart failure and death within four years from diagnosis.