GlaxoSmithkline has turned down options to take on board Ionis Pharmaceuticals' experimental antisense therapies inotersen and IONIS-FB-LRx following a pipeline revamp.

Inotersen is being developed for patients with TTR amyloidosis (ATTR), a rare disease caused by the build-up of amyloid within the tissues of the body damaging the structure and the function of the organs affected.

Ionis said it recently completed a Phase III trial of inotersen demonstrating its “significant benefit” on both primary clinical endpoints of neurological disease progression and quality of life in patients with polyneuropathy due to hereditary ATTR, and that it plans to file the drug with regulators later this year with a view to a launch in 2018.

IONIS-FB-LRx is a ligand conjugated antisense drug in development for the treatment of diseases mediated by the complement system, a part of the immune system concerned with innate immunity.

In a Phase I trials earlier this year the therapy achieved dose-dependent reductions in plasma factor B and also demonstrated a safety and tolerability profile supporting further clinical development, the US biotech noted.

According to Ionis, GSK’s decision to step away from these therapies stems from a reprioritisation of its pipeline and move away from rare diseases, and that, consistent with its focus on treatments for infectious diseases, the drug giant continues to advance two drugs targeting hepatitis B virus (HBV) under its collaboration with Ionis - IONIS-HBVRx and IONIS-HBV-LRx - which are currently in Phase II trials.