An Open Label Extension Study of Monepantel in Individuals With Motor Neurone Disease

ALS/MND is a progressive, fatal neurodegenerative disease; characterized by motor neuron loss resulting in muscle weakness and atrophy, disability, and eventually death from failure of the ventilatory muscles. The median age of onset is 55 years and average survival is 3-5 years after onset of the first symptoms. The only FDA-approved disease modifying medications confer only a modest survival benefit. Given the poor prognosis and dearth of effective treatments, clinical studies are of primary importance for people with ALS/MND.

Abnormal protein accumulation within motor neurons of the brain associates with the cause of ALS/MND. Inhibition of the mTOR signaling pathway slows disease progression in certain preclinical models of ALS/MND and is suggested to provide synergy with the ALS/MND standard-of-care drug, riluzole. PharmAust has shown that MPL and its major metabolite MPL sulfone (MPLS) have activity against mTOR signaling pathways in humans; based on published data, the inhibition of mTOR may be relevant to the treatment of ALS/MND.

This Phase I Open Label Extension will further test the hypotheses that MPL administration to individuals living with ALS/MND will safely reduce disease associated protein accumulation in motor neurons and provide therapeutic benefit. The safety and tolerability of oral monepantel administration and markers of efficacy will continue to be tested in the same participants that completed the Phase I Study (MON-2021-001).

A daily dose of 10 mg/kg monepantel (QD) will be studied in the Open Label Extension Study (MON-2023-001) to further evaluate long-term safety and efficacy in participants with MND/ALS that completed the Phase I Study (MON-2021-001). Based on the previous pre-clinical efficacy data and clinical safety data, a dose of 10 mg/kg QD is estimated to produce the most robust mTOR inhibition while still being well tolerated. The 10 mg/kg QD dose was the maximum dose evaluated in the Phase 1 Study.