ARX-SAFINAMIDE

What it is

ARX-Safinamide is indicated for the treatment of adult patients with fluctuating idiopathic Parkinson's disease (PD) as add-on therapy to a regimen that includes levodopa (L-Dopa). ARX-Safinamide tablets contain 50 or 100 mg safinamide (as mesilate). Safinamide is a highly selective and reversible monoamine oxidase B (MAO-B) inhibitor that causes an increase in extracellular levels of dopamine in the striatum, with MAO-B inhibited with more than 1000-fold selectivity over MAO-A.

Approved indications

— Fluctuating idiopathic Parkinson's disease in adult patients as add-on therapy to levodopa.

Dosing overview

ARX-Safinamide treatment should be started at 50 mg/day, with the dose able to be increased to 100 mg/day after two weeks on the basis of individual clinical need. Safinamide may be taken with or without food. ARX-Safinamide 50 mg can be discontinued without down titration, whilst ARX-Safinamide 100 mg should be tapered by decreasing the dose to 50 mg for one week prior to discontinuation.

Key safety warnings

The development of serotonin syndrome has been reported in patients on concomitant treatment with MAO inhibitors (including selective MAO-B inhibitors), selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, tetracyclic antidepressants, triazolopyridine antidepressants, cyclobenzaprine, opioid drugs and methylphenidate, amphetamine and their derivatives. Serotonin syndrome symptoms may include mental status changes (such as agitation, hallucinations, delirium, and coma), autonomic instability (such as tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, and hyperthermia), neuromuscular symptoms (such as tremor, rigidity, myoclonus, hyperreflexia, and incoordination), seizures, and/or gastrointestinal symptoms (such as nausea, vomiting, and diarrhoea). ARX-Safinamide should not be administered to patients with ophthalmological history that would put them at increased risk for potential retinal effects (such as family history of hereditary retinal disease, or history of uveitis). In clinical trials no retinal degeneration was noted in patients at the maximum human dose. Safinamide may potentiate the side effects of levodopa and/or other dopaminergic drugs, and pre-existing dyskinesia may be exacerbated. In clinical studies, dyskinesia was generally mild to moderate in intensity, with very few patients reporting severe dyskinesia, and there was no increase in troublesome dyskinesias. Somnolence and dizziness may occur during safinamide treatment, and patients treated with dopaminergic medications have reported falling asleep while engaged in activities of daily living, including the operation of motor vehicles, which sometimes has resulted in accidents.

Contraindications

ARX-Safinamide is contraindicated in patients with hypersensitivity to the active substance (safinamide) or to any of the tablet excipients. Concomitant treatment with other monoamine oxidase (MAO) inhibitors is contraindicated, with at least 7 days required between discontinuation of safinamide and initiation of treatment with another MAO inhibitor. Concomitant treatment with pethidine is contraindicated, with at least 7 days required between discontinuation of safinamide and initiation of treatment with pethidine. ARX-Safinamide is contraindicated in patients with severe hepatic impairment, albinism, retinal degeneration, uveitis, inherited retinopathy or severe progressive diabetic retinopathy.

Regulatory history

ARX-Safinamide safinamide (as mesilate) 50 mg and 100 mg tablet blister packs were first listed on the ARTG on 2025-07-08. This medicinal product is subject to additional monitoring in Australia, which will allow quick identification of new safety information.