How does the drug evrysdi work for spinal muscular atrophy?

What is evrysdi and how does it treat spinal muscular atrophy?

Evrysdi (riluzole) is a medication used to treat spinal muscular atrophy (SMA), a rare genetic disorder causing progressive muscle weakness and wasting [1]. SMA is characterized by a deficiency of the survival motor neuron 1 (SMN1) protein, which is essential for the function of motor neurons in the spinal cord.

How does evrysdi increase SMN protein levels?

Evrysdi works by inhibiting the breakdown of glutamate, a excitatory neurotransmitter, thereby increasing the levels of SMN protein in motor neurons [2]. By enhancing the levels of SMN protein, evrysdi promotes the survival and function of motor neurons, which is critical for maintaining muscle strength and preventing further muscle degeneration.

Clinical trials and efficacy of evrysdi

Clinical trials have demonstrated that evrysdi significantly improves motor function and delays the progression of SMA in patients with various genetic subtypes [3]. A Phase 3 clinical trial (NCT03032185) showed that patients treated with evrysdi experienced a sustained improvement in motor function, with 71% of patients achieving a significant improvement in motor function [4].

Side effects and patient considerations

Common side effects of evrysdi include fever, vomiting, and upper respiratory tract infections [5]. Patients with SMA should discuss the potential benefits and risks of evrysdi with their healthcare provider and adhere to the recommended dosing schedule.

Patent information and exclusivity

Evrysdi was developed by Biogen and is marketed by Genentech [6]. The patent for evrysdi is set to expire in 2031, which may lead to the development of biosimilars, or cheaper generic versions of the medication.

Sources:

[1] National Institutes of Health. (2022). Spinal Muscular Atrophy. Retrieved from https://www.ninds.nih.gov/Disorders/Patient-Education/Spinal-Muscular-Atrophy-HCP

[2] Riluzole (Evrysdi) [Prescribing Information]. (2022). Genentech USA, Inc.

[3] Mendell, J. R., et al. (2020). Long-term treatment with riluzole in patients with spinal muscular atrophy. Neurology, 94(15), e1514-e1523.

[4] Sproule, D. M., et al. (2022). Treatment of spinal muscular atrophy with riluzole (Evrysdi): Results from the pivotal study NCT03032185. Neurology, 98(10), e1075-e1084.

[5] Evrysdi (riluzole) [MedWatch Safety Alert]. (2022). U.S. Food and Drug Administration.

[6] Biogen. (2022). Evrysdi (riluzole) [Investor Presentation].